galene irrigation system project

Preliminary Design of Gelana Irrigation Project June 2009

CHAPTER ONE

1. INTRODUCTION

1.1 GeneralIrrigation is essential to overcome water deficiencies and ensure stable agricultural production throughout the year. It is vital in areas where the amount and timing of rainfall are not adequate to meet the moisture requirement crops. This is the fact why management of water resource became very important. Through country has enough source of water for irrigation and arable lands, only insignificant amount has been utilized. Major cereal food production in the country is based on rain-fed agricultural by small-holder farmer. This situation has exposed to rural population to repeated cycle of famine as the result of annual crop failure due to drought.

To increase the role of irrigated agriculture in the country, the water sector development program for the period from 2002-2016 gives irrigation a prominent place by proposing about 274,000 hectares of lands to developed in the 15-years period of under large, medium and small scale irrigation. One of the projects in this program is Gelana irrigation project.

1.2 Location of project area The project area is located in an Abaya-Chamo sub-basin 0f the rift valley lakes basin found in the southern part of the country with in Oromiya and SNNPR regional states. The Gelana irrigation project area is located between 50 25'-6O18'N and 37050'-380 20' E at about 450 km south of Addis Ababa both in SNNPRS (Amaro special District) and Oromia reginal state (Galana District) to south of lake Abaya

1.3 RiverThe available flow is the Gelana River which flow of Yirga Chefe (upper valley) and enter a narrow gorge though which it descends down the stream edge of the African Rift Valley. Finally, the River traverses through a

Arba Minch University Department of final year projectWater Resources &Irrigation Eng’g 1


seasonally flooded zone known as the Bore swamp and eventually flow to Abaya Lake. The annual flow in the Gelana River in the valley varies considerable with a mean flow of 5.6 m3/s(180M m3) with dry season discharge reaching as low as 300 l/s.

1.4 TopographyThe Gelana irrigation project is in the middle valley of Gelana River, with elevation 1300m M.S.L. The proposed irrigation area covers about 11,834 hectares of which 0nly some 6200 hectares area will be irrigated. The balance area is left out due to unstable soil, uneven topography and dense bush area along Gelana and Jelo River. The slope analysis is important to classified the capability of land, land use planning and conservation need. The result of slope analysis in the major party of the project is a gentle slope.

1.5 Climate of the areaThere are six observation stations for recording climate data near the project area.Those metrological stations are located Amarokello, Arba Minch, Burji,Fisseha Gent,Ager Mariam andYirga Chefe.There fore ,Arba Minch station is used as an alternative station located in the same climatic condition to the project area. This station is adapted for estimation of both the open water evaporation (EO) and Reference ETO for the project area.

1.6 Objective of the projectThe main objectives of the project are:

To increase the income of beneficiaries that gradually changes their living standards.

To utilize exiting resource in better way and reduce wastages material and human dependency in rainfall

To improve the socio economic life community by increasing per capital income.

1.7 Socio and Economic study

1.7.1General

Farming with traditional cultural practices forms the livelihood of the community. Around the project area rain fed agriculture is the existing



means of survival for the farmers, which is supported by live stock production. Because of the poor performance of agricultural production system its consequent results, the farmers are exposed to food shortage and forced to live below the subsistence level. Irrigation development is the option to improve the living standard of the area. This ensures food self-sufficiency and reduces poverty.

1.7.2 Labor supply and Demand

During construction in the project area there is no shortage of labor. For excavation and other unskilled construction works labor can be easily found around the site. Farmers can be immediately available labor directly to involve in the labor contribution and large quantities of material in which accessibility, uniform and availability for engineering materials constriction.

1.7.3Project Benefits

The implementation of the project will have social and economic importance in improving the livelihood of the population .It also increases the productivity and production, brings changes in social development, improves income of the beneficiaries and improves socio cultural facilities

1.8 Geology

1.8.1General

Generally the geological observation around Gelana irrigation project is covered by volcanic rocks principally basalt dipping to wards east. The rock is found highly weathered and distributed to a depth 5m in the center valley and to greater depth on the right and left abutment. Afoul zone was identified near main flow River.

1.8.2Soil

The soil of the project area is the result of weathering and decomposition of volcanic rocks particularly from the basalt. Soil has been recognized in the vicinity of the project which is alluvial loam silt soil.Generally the project area has good potential for agricultural have the following physical.

Land form; The land form of Gelana Commanded undulating slope 5-8%



Altitude; Altitude of Commons area is from 1300m above sea level from top dawn of command.

Slope shape; the command area has almost irregular shape. Ground water; the command area has deep ground water. Permeability: The command area soils have moderately slow

permeability Flooding: There is no flooding problem in entire command area. Accumulation water: There is no problem of pounding water in enter

of command area. Erosion condition: It is undulating micro topography of slope (5%-8%)

acceleration of erosion at the project is slightly and surrounding is middle.

Effective soil depth: The command area has very effective depth of soil of greater than 150 cm.

Color: The command area has reddish brown surface color when moisture.

Structure: The surfaces oil structure of the command area is medium. Consistency: The consistency of soil of command area is slightly hard

when dry, friable when moist and plastic when wet. Pores: Pores are common with medium site Parent material: The parent material of the area is igneous rock

basalt)

1.9 Water qualityThe qualities of available water more desirable than soil characteristics in determine the suitability of lands for irrigation. So quality of Gelana River is good for irrigation and salinity problem of the water is expected free. This may concluded that the area selected for irrigation project.

The various types of impurity which the water unfits for irrigation area classified us;

Sedimentation concentration in water. Total concentration of soluble salt in water. Proportion of sodium ions to other cation. Concentration of potentially toxic element present in the water. Bacteria contamination



CHAPTER TWO

2 HYDROLOGICAL DATA ANALYSES

2.1 GeneralHydrology, which treats all faces of the earth water, is subject of great importance for people and there environment. Practical applications of hydrology are found in such tasks as the design and operation of hydraulic structures. The role of hydrology is to help analyzing the problems involved in these tasks and to provide guidance for the planning and management of water resources.Different attributes of hydraulic structures are directly dependant on the peak flood magnitude adopted in the design process and the stream flow records available at the project site. Hence, stream flow (precipitation) records are the major data required in planning and operation of hydraulic structures.

2.2 Checking Available DataIn the design of a project it is vital to collect or to obtain relevant data. For realistic and accurate design, it is essential that the collected data should be continuous, consistent, reliable and adequate.Gauged mean monthly rainfall station &monthly volume of stream data are available in the Gelana irrigation project. These data are not used to determine the maximum flood. The maximum probable rain fall is obtained from rainfall intensity duration frequency analysis &depth storm, so it is sufficient for analysis. As a result it is necessary to go for the determination of runoff using complicated relationship between precipitation and runoff.



2.2.1 - Adequacy

It refers primarily to length of records, but scarcity of data collecting stations is often a problem. If the sample is too small, the probabilities derived can not be expected to be reliable. Generally a minimum of 30 years of data is considered as essential. Smaller lengths of records are also used when it is unavoidable. However, frequency analysis should not be adopted if the length of records is less than 10 years. Therefore, 23-years record of mean rain fall available for Gelana irrigation project that is enough to determine the maximum flood.

2.2.2 - Continuity

The continuity of a record may be broken with missing data due to many reasons such as damage or fault in recording gauges during a period. Fortunately the given 23-year rain fall record of Gelana irrigation project was not found with missing data.

2.2.3 Design Discharge Determination

A flood used for the design of a structure on consideration of its safety, economy, life expectancy and probable damage consideration for important structure at strategic locates, virtually non-risk can be taken for its failure. The flood selected for design of such structure should be probably be the highest For any structure hydrological analysis at least ten year daily peak discharge should available .The available rainfall should also be recent collected, but for Gelana irrigation project the available data mean monthly rainfall& monthly flow, which is not recommended to generate peak flood. Table 2.1 Mean monthly rainfall value over the study in mm.

Station Duration

Jan Feb Mar Apr May Jun July Aug Sep

Amaro killo 1983-2005

23.5 32 73.5 203.3 165.4 57.6 48.7 66.4 96.



Arba Minch

1987-2005

34.1 39.2 50.2 167.9 150.9 65.1 43.0 46.3 70.2

Burji 1956-2005

30.5 31.2 87.6 180.8 157.5 44.7 39.6 38.1 76.4

f.genet 1983-2005

33.9 46.8 83.5 196 231.4 97.9 80.2 97.2 141.5

H.mariam 1975-2005

15.5 26.3 79.3 194.4 225.2 68.8 42.1 37.2 66.2

Y.chefe 1970-2005

26.2 41.2 10.5 259.1 266.9 115.8 91.5 109.8 186.3

Continues from above table duration Oct Nov Dec Annual

Amorokello 1983-2005 149.7 73.8 24.2 1014.1

Aba Minch 1987-2005 120.7 62.2 41.3 891.6

Burji 1956-2005 245.0 77.2 27.5 1036.2

f.genet 1983-2005 195.4 76.1 33.3 1313.3

Hagere mariam 1975-2005 128.1 72.8 14.7 970.6Yirga chefe 1970-2005 236.4 86.5 26.6 1551.8

2.2.4 Rainfall intensity –duration frequency (IDF) analysis

IDF relation ships are use full to determine the depth of storm rainfall of different return periods & duration. According to regional IDF curvethe total storm rainfall starting from 1-hour duration to 72-hours is shown in table 2.2 for various return periods occurances.the24-hour total storm rain fall depth is recommended for the irrigation engineer to generate the design parameters of discharge at field level.

Table2.2 the rainfall depth for different duration &return period to be used for GelanaIntensity(mm/hr)for T returnPeriod

Total rainfall depth(mm) for T return period



Hrs

T=2 T=5 T=10

T=25

T=50

T=100

T=2 T=5 T=10

T=25

T=50

T=100

1 32.2 41.9 48.1 53.3 58.2 41.9 32.2 41.9 48.1 53.3 58.2 41.13 12 16.6 19.2 21.3 23.5 16.6 37.7 49.7 57.5 63.9 70.4 49.76 6.8 8.9 10.3 11.5 12.7 8.9 40.6 53.5 62.1 68.7 75.9 53.512 3.6 4.7 5.5 6.1 6.7 4.7 43.3 56.9 66.1 72.8 80.6 56.924 1.9 2.5 2.9 3.2 3.5 2.5 46.0 60.1 69.9 76.5 84.7 60.948 1.O 1.3 1.5 1.7 1.8 1.3 48.8 63.3 73.6 80.1 88.7 63.372 0.7 0.9 1.1 1.1 1.3 0.9 50.4 65.2 75.8 82.2 91.0 65.2The 50 years return period &24-hour duration is selected for maximum probable storm depth from table 2.2The IDF curve generate from Gelana storm rainfall Design storm=84.7mm

Table 2.3 data for determination design flood

Maximum probable depth of storm

P mm 84.7

Area of catchment A Km2 250Length of main water course from watershed divide to proposed diversion or storage site

L m 80000

Elevation of watershed divide opposite to the head of the main water course

H1 m 1700

Elevation of stream bed at proposed or storage site(top0 map)

H2 m 1293.5

Slope of main water course ; S=(H1-H2)/L

S m/m 0.005

2.2.5 Estimate of peak flood

1. Rational Method 2. Empirical formula Method



3. Synthetic Unit Hydrograph Technique (Snyder’s method) 4. Flood Frequency Analysis Method 5. USSCS (United States Soil Conservation Service)

1. Rational Method

The rational formula is found to be suitable for peak flow prediction in small catchments up to 50km^2 in area. It finds considerable application in urban drainage designs and in designs of small Culverts and Bridges. The basic equation of rational method is given by

Qp=1/360*A*C*I

Where Qp is peak discharge (m3/s)

C -runoff coefficientItc, I-The mean intensity of precipitation (mm/Hr) for a duration

equal to tc . P- Precipitation

A- Drainage area in hectare (ha)The use of this method to compute Qp requires parameters; Tc, (Itc, p) and Limitation:

a. Calculation of weighted run off coefficient is by far difficult as the catchments covered by different land features with varying area coverage (which is not known for Gelane project catchments)

b. This method is applicable for small areas up to 50km2.c. Estimation of Itc, p requires some other regional

constants based on catchments behavior.

Because of the above limitations (250km2greaterthan50km2), rational method is not convenient for the determination of peak flood for Gelana irrigation project.

2. Empirical formula Method The empirical used for estimation of flood peak are essentially regional formula based on statistical correlation of the observed peak and observed catchments parameters.Generally, this method is given as a function of catchments area.



QP=f (A)

For example Admassu developed an empirical formula through regression analysis of 42 catchments in Ethiopia with area ranging from 200-9980km^2.

QP=Q (1+kt*Cv) ---------------------------general formula

Q=.87*A^.7---------------------------------Dr.Admassu’s relationWhere A-Catchments area (km2) Kt-frequency factor

Kt =

T=return periodCv=the average Coefficient of variation (=.38 for most cases)

The formula is safely adopted for most Ethiopia basins under the given area range, however; the basin area under our consideration is not in the domain and hence we can’t use this method to estimate the peak discharge.

To developed unit hydrographs for catchments, detailed information about the rain fall is needed. Then the resulting flood hydrograph are obtained. However, this formula not applicable for our case, because we have the area & the length catchments

2. Synthetic Unit Hydrographe Technique (SNYDER’S METHOD)

such information would-be available only at few locations and in majority of catchments the data would normally be scanty .In order to construct unit hydrograph for such areas, empirical equations of regional validity that relate the salient hydrograph characteristics to the basin catchments are available .Unit hydrographs derived from such relation ships are known as Synthetic Unit Hydrographs.

Snyder’s Method

Snyder (1938) developed a set of empirical equation for synthetic unit hydrographs in USA. This equation used with some modifications in many other countries and so called Snyder’s Synthetic Unit Hydrograph.



The first of the Snyder’s equation relates the basin lag tp, defined as the interval from the mid point of the unit rain fall excess to the peak of unit hydrograph, to the basin characteristics as ,

Tp=Ct (L*Lca) hr

L – Basin length measured along the watercourse from the basin divide to the gauging station in km.

Lca – distance along the watercourse from the gauging station to appoint opposite the watershed centered in km.

Ct – regional constant, representing watershed slope &storage.

Better correlation of basin lag tp with catchments parameter, (L*Lca)/ is obtained by et al .as

Tp=Ctl [

Where Ctl and n are basin constants & s is basin slope

Snyder as gives standards duration tr hrs of effective rainfall

Tr=

The peak discharge Q[m3/s] of a hydrograph of standard duration tr hrs is given by Snyder as

QP= where A-Catchments area km2

Cp – a regional constant

If anon standard rain fall duration tr is adopted, instead of the standard value tr derive a unit hydrograph, the value of the basin lag’s affected .The

modified basin lag is given by: tp’=tp+ where tp – basin lag in

hrs for an effective of Tr hr. =



The peak discharge for a non standard effective rainfall of duration Tr in m3/s is

QP=

When Tr=tr, QP=Qps

Snyder as gives the time base (tb) of unit hydrograph

Tb=3+

Finally, to assist in the sketching of unit hydrographs at 50 percentage &75% of the peak have been found US catchment’s by the US army corps of engineers. These widths are given by:

W50=

Where W5 – width of unit hydrograph in hr at 50% peak discharge

W75-width of unit hydrograph in hr at 75% peak discharge

Q=QP/A, peak discharge per unit catchments area in m3/s/km

Since the coefficients Ct and Cp vary from region to region , in practical application .It is advisable that the value of these coefficients are determined from known unit hydrograph of a meteorologically homogeneous catchments and other used in the basin under study.For our case Snyder’s method is not applicable because, it works for derivation of unit hydrograph for cachement, where rain fall & run off data not available.

4. Flood Frequency Analysis Method

When the stream flow peaks are arranged in the descending order of magnitude, they constitute statically array whose distribution can be expected in terms of frequency of occurrence. The probability ‘p’ of each event being equal to or exceeded (plotting position) formula.

P=

Where m=order number of the events and N=Total number of events in the data. The recurrence interval (T) return interval, is calculated as



T=

In our case there is measured flow data it is possible to determine the probability of occurrence of daily maximum rainfall (rain fall frequency analysis).The general equation for flood frequency analysis is:

XT=Xav+k*sd-------------------------------------- (Chow 1951)

Where XT=Value of variant(X)of random hydrologic series with return period (T)

Xav=Mean value of variant

sd=standard deviation of variant

k=frequency factor which depends up on the return period (t) and assumed frequency distribution.

This also not applicable, because our given data are area, length& slope of the catchments’.

Table 2.4 Guidelines For selecting Design floods [source R.Baban,page30]

№ Structure Return period

1 Spillway for projects with storage of more than

60*10m3/sec

1000

(a)



2 2 Barrage and minor dams with storage less than

60*106 m3/sec

100(a)

3 Spill way of small reservoirs dams in the country sides ,not endangering urban resident

10-20(b)

4 As above (3) but located so as endanger other structure Or urban residences incase of failure

50-100(b)

5 Diversion weir 50-100(a)

6 Small bridges on main highways 50-100(b)

a- Subrimanya 1989

b- Nemec 1972

5. USSCS (United States Soil Conservation Service)

This method also known as hydrologic soil cover complex number method was developed by united state: under department agricultural soil conservation for determine peak rate of run off from water shades. a run off curve number(CN)is developed through field studies by measuring run off from different soil at various lacotion.the antecedence moisture condition &physical characteristics of the water shade are correlated to give hydrologic soil groups. Finally this method hydrograph synthesis to be represent in a simple geometric form as a triangleThe design flood, which is expected ton, occur during period of the diversion scheme, is therefore determined by USSCS method to this end the storm that is estimated by IDF is adopted.Table 2.5 calculation for determination design flood

Step designation/formula Symbol unit value1 Area of catchment A Km2 2502 Length of main water

course from watershed divide to proposed diversion or storage site

L m 80000



3 Elevation of watershed divide opposite to the head of the main water course

H1 m 1700

4 Elevation of stream bed at proposed or storage site (topo map)

H2 m 1293.5

5 Slope of main water course ; S=(H1-H2)/L

S m/m .005

6 Time of concentration

Tc=

Tc hr 16.65

7 Rain fall excess duration D=Tc/6 ; ifTc<3hrsD=1hr.if Tc>3hrs

D hr 1

8 Time to peak Tp=.5D+.6Tc

Tp hr 14.99

9 Time base of hydrograph Tb=2.67Tp

Tb hr 40.02

10 Lag time TL=.6Tc TL hr 9.9911 Peak rate of discharge

created by 1mm run off excess of whole of the catchments qp=(.21A)/Tp

qpM3/s.mm 3.502

12 13 14 15 16 17 18 19duration Daily

point rainfall for return

RainfallRatio as daily rainfall

rainfall

Areal toRainFall

arealrainfall

incremental

DescendingOrder



peroid of 50 years

ratio

Hr mm % mm % mm mm Number0-1 84.7 45.7 38.7 55 21.8 21.8 (1) 21.281-2 58.6 49.6

366 32.7

611.48 (2)11.48

2-3 67.1 56.83

71 40.35

7.59 (3)7.59

3-4 71.4 60.48

74 44.76

4,41 (4)5.07

4-5 76.4 64.71

77 49.83

5.07 (6)4.41

5-6 78.6 66.57

78 51.92

2.09 (7)2.07

12 Fill 0-Dhr, D-2Dhr, …5D-6Dhr13 Determine the magnitude of the daily rain fall with the given

recurrence interval by applying statistical method 13Determine the magnitude of the daily rainfall with the given recurrence

interval by applying statistical method.14 Read from Annex ----fig---,the rain fall profile

(%) occurring in D, 2D, 3D, 4D, 5D, 6Dhrs and put in 14.15 Multiply col.13 and col.14 to find the rainfall profile (mm) enter in 15.16 Read from table ----area to point rainfall ratio for different duration in

particular catchments.17 Multiply col.15 and col.1618 Calculate incremental rainfall by deducting the current Arial rainfall

from the preceding Arial rainfall as written in 18.19 Assign order to the rainfall depths in descending order 1-620 21 22 23 24 25Rearranged order

Rearranged incremental rain fall

Cumulative rainfall

Time of incremental hydrograph



Time of beginning(hr) Time to peak(hr)

Time to end(hr)

6 2.09 2.09 0 14.99 40.024 5.07 7.16 1 15.99 41.021 21.28 28.44 2 16.99 42.022 11.48 39.92 3 17.99 43.023 7.59 47.51 4 18.99 44.025 4.41 51.92 5 19.99 45.02

20 From 19 mention the rearranged order as6,4,3,1,2,5 (arbitrary but considering ascending and descending feature of hydrograph ordinate where peak value is middle of the hydrograph).

21 Fill in the corresponding incremental rain fall value to the rearranged order of 20 from 17.

22 Fill in the cumulative rainfall value of 21 by adding with the rainfall value in preceding duration.

23 Fill in the time of beginning of the hydrograph 0,D,2D…,5Dhr24 Fill in the time peak as Tp,D+Tp,2D+Tp,…,5D+Tp or add Tp in every

value of 23 and mention in24.25 Fill in the time of end as Tb,D+Tb,2D+Tb,…5D+Tb26 27 28 29 30Land use cover

Area ratio (%)

“CN”Hydrological soilGroup “C”

Weighted”CN” “CN”AMC CN

1.Row crop-poor

52 88 45.76 II 84.0

2.bush land-Fair

23 73 16.79

Grass land-Poor

25 86 21.5 III 93



26 Identify all type of land cover such as cropped area, woodland, fallow land, pastures, meadow, etc...From catchments map or areal photo.

27 Find ratios of each type of land use cover to the total catchments area is and enter 27.

28 As certain hydrological soil groups each types of land use cover as below. Group A: low run off potential Group B: moderate run off potential Group C: moderate high run off Group D: high run off potential Find the corresponding curve number(CN) From table 2.6 Annexe- B

29 Multiply column.27 and col.28 and inter in col. 29

30 Add col. 29 the CN is corresponding to antecedent moisture condition III (AMC-III). Find CN for AMC-III from table 2.7 Annex-B

No

Description/Formula Symbol

Unit Example

31 Find the maximum potential deference b/n rainfall(P) and direct run off (Q), which is given by the following formula.

S=

CN= value of corresponding to AMC -III

S M CN=93S=19.12

32 Substituting the value of “S” in the following formula, giving the relation b/n direct run off (Q) and rainfall (P).



Q=

33

Substituting the value of P1 as mentioned in col. 20,in the above formula and fined find the corresponding value of Q(33)enter ;Enter the value of Q in col. 35.

22 23

P(mm) Q(mm)2.09 0.17297.16 0.495628.44 14.112839.92 23.596047.51 30.386951.92 34.4148

34 35 36 37 38 39Duration

Value of Q

Incremental run off

Peak runoff for increment

Time of beginningCol.(23)

Time to peakCol.(24)

Time to endCol.(25)

Composite hydrograph

Hr mm mm M3/s Hr Hr Hr1-0 0.1729 0.1729 0.6055 0 14.99 40.021-2 0.4956 0.3227 1.1300 1 15.99 41.022-3 14.112

813.6172 47.6874 2 16.99 42.02

3-4 23.5960

9.4832 33.2102 3 17.99 43.02

4-5 30.3869

6.7909 23.78117

4 18.99 44.02

5-6 34.4148

4.0459 14.1687 5 19.99 45.02

34 Enter the same time as in col.12, 0-D,D-2D,2D-3D,…,5D-6D.35 There are the value of Qas found out in col.33 corresponding to the



value of P36 F incremental runoff by reducing the value of col;35 by preceding

value.37 Multiply col. 36 and peak rate of run off corresponding to 1mm run off

excess as found incol.1138 Plot triangular hydrograph with time of beginning, peak time and time

to end as mentioned in 23,24,25 and peak run off as mentioned in col.37

39 Plot composite hydrograph by adding all the triangular hydrographs .The resultant hydrograph will be composite hydrograph of desired return period. The coordinate of the peak of hydrograph will give the peak run off with desired return period.

Table 2.6 determination of triangular hydrograph

HOUR Q1 Q2 Q3 Q4 Q5 Q6 QT0 01 0.04 0 02 0.08 0.0754 0 0.0754

3 0.12 0.15083.1833 0 3.3341

4 0.16 0.22626.3644 2.2182 0 8.8088

5 0.2 0.30169.5455 4.4335 1.5865 0 15.8671

6 0.24 0.37712.727 6.6488 3.173 0.9438 23.8692

7 0.28 0.452415.908 8.8641 4.7595 1.8891 31.8728

8 0.32 0.527819.089

11.0794 6.346 2.8344 39.8764

9 0.36 0.6032 22.2713.2947 7.9325 3.7797 47.88

10 0.4 0.678625.451 15.51 9.519 4.725 55.8836

11 0.44 0.75428.632

17.7253 11.1055 5.6703 63.8872

12 0.48 0.829431.813

19.9406 12.692 6.6156 71.8908



13 0.52 0.904834.994

22.1559 14.2785 7.5609 79.8944

14 0.56 0.980238.175

24.3712 15.865 8.5062 87.898

14.990.60524

1.05485

41.325

26.5643

17.435635

9.442047

95.82156

15 0.605 1.055641.357

26.5865 17.4515 9.4515 95.9016

15.990.58104

1.13025

44.506

28.7796

19.022135

10.38735

103.8252

16 0.5808 1.12644.538

28.8018 19.038 10.3968

103.9002

16.990.55684

1.08145

47.687

30.9949

20.608635

11.33265

111.7046

17 0.5566 1.08147.662

31.0171 20.6245 11.3421

111.7263

17.990.53264

1.03645

45.775

33.2102

22.195135

12.27795

114.4952

18 0.5324 1.03645.756 33.194 22.211 12.2874

114.4848

18.990.50844

0.99145 43.87

31.8803

23.781635

13.22325

113.7469

19 0.5082 0.99143.851 31.867 23.767 13.2327

113.7089

19.990.48424

0.94645

41.965

30.5533 22.8265

14.16855

110.4598

20 0.484 0.94641.946 30.54 22.817 14.161 110.41

21 0.4598 0.90140.041 29.213 21.867 13.595

105.6168

22 0.4356 0.85638.136 27.886 20.917 13.029

100.8236

23 0.4114 0.811 36.23 26.559 19.967 12.463 96.0304

24 0.3872 0.76634.325 25.232 19.017 11.897 91.2372

25 0.363 0.721 32.42 23.905 18.067 11.331 86.444

26 0.3388 0.67630.515 22.578 17.117 10.765 81.6508

27 0.3146 0.631 28.61 21.251 16.167 10.199 76.8576

28 0.2904 0.58626.704 19.924 15.217 9.633 72.0644



29 0.2662 0.54124.799 18.597 14.267 9.067 67.2712

30 0.242 0.49622.894 17.27 13.317 8.501 62.478

31 0.2178 0.45120.989 15.943 12.367 7.935 57.6848

32 0.1936 0.40619.084 14.616 11.417 7.369 52.8916

33 0.1694 0.36117.178 13.289 10.467 6.803 48.0984

34 0.1452 0.31615.273 11.962 9.517 6.237 43.3052

35 0.121 0.27113.368 10.635 8.567 5.671 38.512

36 0.0968 0.22611.463 9.308 7.617 5.105 33.7188

37 0.0726 0.1819.5576 7.981 6.667 4.539 28.9256

38 0.0484 0.1367.6524 6.654 5.717 3.973 24.1324

39 0.0242 0.0915.7472 5.327 4.767 3.407 19.3392

40.02 0 0.04513.8039

3.97346 3.798 2.82968

14.45014

41.02 01.8987

2.64646 2.848 2.26368

9.656836

42.02 01.31946 1.898 1.69768 4.91514

43.02 0 0.948 1.13168 2.0796844.02 0 0.56568 0.5656845.02 0 0



Fig 2.1: Composite triangular Hydrograph

From composite triangular hydrograph the maximum peak flood is 114.95 m3/s. Design Flood with a return period of 50 years is Qd=115m3/s

CHAPTER THREE

3. WATER DEMAND AND WATER DELIVER

3.1 GeneralEvery crop requires a certain quantity of water after a certain field interval

throughout its period growth .If the natural rain is sufficient and timely soas

satisfy both those requirement no irrigation water is required for raising

that crop. But countries like Ethiopia the natural rainfall is erratic if it does

so meeting the timely requirement is a must. Crop water requirement is



defined as the total amount of water required at fixed head to mature a

crop, of course, it is includes the amount required to meet loss though

evaporation losses through transpiration, plant metabolism needs

application and quantity of water required for operational land preparation,

leaching etc.

3.2 Crop Water RequirementCrop water requirement is the total quantity of water needed by it’s from

the time it is shown the time it is harvested. The crop required water

through out the growing period. The water requirement of crop may be

contributed from different source such as irrigation, effective rain fall, soil

moisture storage and ground water contribution

CRW=IR+ER+S+GW

Where CWR=crop water requirement

IR=irrigation requirement

ER=effective rain fall

S=soil moisture in root zone

GW=ground water contribution

Irrigation requirement of crop (IR); it is defined as the part of water

requirement

of crops that should be fulfilled by irrigation.

IR =CWR-(ER+S+GW)

effective rain fall defend as the rain fall that stored in root zone & can be

utilized by crop. But all the rain fall that falls is not use full or effective

different methods to determine effective rain fall from monthly total rain

fall data. Fixed percentage effective rain fall is taken as a fixed percentage.

The monthly rain fall

ER=% of total rain fall



1. Dependable Rain fall

Crop water need can be fully or partly meet by rain fall. Rain fall for each

Period will vary from year to year &therefore. rather than using mean rain

fall data (saying rough one year drier &next wet. a dependable level of rain

fall should be selected (saying the depth of rain fall that can be expected in

four out five years or 80% probability of exceedence).also the degree of

shortage below the dependable level during the dry year should given,

science loss in crop yield during the dry year, May significantly, affect to

the project economic visibility.

Ranking Method

Rain fall data ware arranged in descending order for each month without

change them in to annual value rainfall figure ware arranged in descending

order for each month &80% probability of exceedence obtain.

Table 3.1 Mean rainfall over the study area.

Rank

(m)

Jan Feb Mar App May Jun July Aug P=(m/

(N+1))

*100

1 34.

7

46.

8

105.

5

259.

1

266.

9

115.

8

91.

5

109.

8

14.28

2 33.

9

41.

2

87.6 203.

3

225.

2

97.8 80.

2

97.2 28.57

3 30.

5

39.

2

83.5 196.

0

231.

4

68.8 48.

7

66.4 42.86

4 26.

2

32.

o

79.3 194.

4

165.

4

65.1 43.

0

46.3 57.11

5 23.

5

31.

2

73.5 180.

8

157.

5

57.6 42.

1

38.1 83.33

6 15. 26. 50.2 167. 150. 44.7 39. 37.2 85.71



5 3 6 9 6

Extension the above table

Rank Sep Oct Nov Dec P=(m/

(N+1))*100

1 186.3 236.4 86.5 41.3 14.28

2 141.5 245.0 77.2 33.3 28.57

3 96.0 195.4 76.1 27.5 42.86

4 76.4 149.7 73.8 26.6 57.11

5 70.2 128.1 72.8 24.2 83.33

6 66.2 120.7 62.2 14.7 85.71

80% dependable rain fall is obtained from table 3.1 by interpolating.

Jan Feb Mar App May Jun Jul Aug

23.8

4

31.30 74.2

3

182.2

6

158.

5

58.5

5

42.

2

39.1

4

Sep Oct Nov Dec

70.9

8

130.8

0

72.9

2

24.50

The above table dependable rainfall used to determine crop water

requirement. Dependable effective rainfall give minimum value compared

the other method, So it is desirable for design purpose.

Where m=ranking

N=number of sample

P=probability exceedence



2. Method of USDA Soil Conservation Service

The effective rain fall is collected accurately to the formula developed by

the USDA soil conservation service.

Effective rain fall =

Ground Water Contribution (GWC):

The actual contributed from the ground water table is dependable on the

depth of ground water table below the root zone & capillary character tic

of soil .for clay soil the rate of movement is slow &distance p ward

movement is high while for light texture soil the rate is high &distance of

movement is slow.

Soil moisture (S)-this the moisture retained in the root zone between

cropping season.

Net irrigation requirement (NIR)-after the exact evapotranspiration of

crop has been determined. The NIR should be determine .this is the net

amount of water applied to the crop by irrigation exclusive of ER, S & GW

NIR=CWR-ER-S-GW

Gross irrigation requirement (GIR) more amount of water than the NIR is

applied during irrigation to compensate for un avoidable losses.

GIR= where Ea is application efficiency

3.3 Selection of CropCrop is selected basis of the following guideline

1. Climatic requirement



2. Marketability (demand)

3. Popularity (stable food for local people) requirement

4. Yield response and water utilization

6. Soil requirement

7. Method of irrigation

Based of the guideline and suitability for Gelana irrigation project the

following crops are selected from feasibility study of the area. Those are

Industrial-cotton Cereal crops-maize and beans Vegetables-paper and onion

Fruit- Banana Crop selected are found to be suitable with the overall

condition of the project. The crops along with proposed colander are shown

below. As stated can the area has got two rain seasons and the dry seasons

occur from September to March.

Table 3.2 proposed calendar crop

NO crop Base

period

Land

preparatio

n

Sowing

date

Harvestin

g date

1 Cotton 195 May-1 Jun-30 Jan-1

2 Maize-1 80 Feb-1 March-1 Jan-4

3 Maize-2 125 Aug-1 Sep-1 Jun-20

4 H/bean-1 100 Feb-1 March-1 Jun-9

5 H/bean-2 75 Aug-1 Sep-1 Jan-15

6 paper 210 Aug-1 Sep-15 App-13

7 banana 365 Feb-1 March-1 March-1

8 onion 210 Aug-1 Sep-15 App-13

Area coverage



Area distribution of each crop is shown below, the criteria for land

distribution is yield for the crop, price on the market and allocation

Table3.3 area covered by selected crop, for season one & two.

Season -1

Planting date from September

Intensity 75%

Cultivable Area =6200ha*0.75=4650ha

Crops Areain

percentage

Planting date Area in (ha)

Maize-2 30 Sep-1 1860

H/been 20 Sep-1 1240

Paper 10 Sep-15 620

Onion 10 Sep-15 620

Season -2

Planting date from March

Intensity 100%`

Cultivable Area =6200ha*1=6200ha

Crops Area in

percentage

Planting date Area in (ha)

Cotton 25 Jun-30 1550

Maize-1 40 March-1 2480

h/been 30 March-1 1860



Banana 5 March-1 310

3.4 Cropping PatternIt is the sequence of crop grown over the area in cropping season. There

are two cropping season in the project area, the crop pattern must be

planned, in order to irrigated during the critical demand of water. Crop

pattern depend on the following factors

Type of the soil: Detail survey should be carried out to determine the

suitability of the soil.

Climatic condition: The climatic condition of the area should be suitable

for the proposed crop.

Value of crop: The selected crop which have high market value

Socio-economic aspect: When deciding the crop pattern, the socio-

economic aspect and requirement of the region must be considered.

3.5 Determination of Crop water requirementThe amount of water required compensate the evapotranspiration loss from

the filed is defined as crop water requirement. Using to the difficulty of

obtaining accurate filed measurement predication method for crop water

requirement are used .the most important data needed to be known.

1. The effect of climatic in crop water requirement.

2. The effect of crop x-ices in crop water requirement

3. This is generally given by crop coefficient (KC) which presents the

relationship between references ETO of evapotranspiration ETC or

ETC=KC*ETO

4. The effect of local condition & agricultural practice s on crop water

requirements.



This includes the local effect of variations in climate over time, distance &

altitude. Size of fields, soil water availability irrigation water quality etc.

3.5.1Reference evapotranspiration (ETO)The reference evapotranspiration is defined as the rate of

evapotranspiration from an extensive surface of 8 to15cm tall, green grass

cover of uniform height actively growing, completely shading the ground

and not short of water. It can be measured or computed by

1. Direct method

2. Indirect(empirical) method

1. Direct method

-by soil moisture sampling

-by filed experiment

2. Indirect method

Blenny criddle method.

Radiation method

Pan evaporation.

Modification pen man method.

Penman Monteith method.

Determination of ETO

1 Blaned-criddle method

This method in suggested where only the temperature data available and

given

ETO=c (p (0.467+8)

Where ETO=reference crop evapotranspiration in mm/day from the month

considered.

T= mean daily temperature in degree centigrade over month



P= mean daily percentage of total annual day hour obtain from table for a

given Month & latitude

C= adjustment factor which depends on minimum relative humidity

sunshine hours& daytime wind estimate

2. Thorn Waite method

This also available for temperature data

ETO=1.6*b*(10*Tm/I)

Where ETO=potential evapotranspiration cm/month

Tm =mean monthly temp in cº

I=actual heat index obtain from monthly heat index I the year

I=(Tm/5) 1.514 and I= = (Tm/5)

Constant a & b obtained as

A = (67.58*18 ) I -(7.71*10 ) I + (0.01791) I+ (0.492)

B=

2. Hargreaves class A Pan evaporation Method

CU is related to pan evaporation (EP) by constant Kc consumptive use

coefficient

ET=Kc*EP

Where EY =CU =consumptive use

EP = pan evaporation

EP = 0.4592*Ct*Cw*Ch*Cs*Ca

Where Ct= coefficient of temperature



=0.393+0.0279bTc+0.0001189Tc

Tc =mean temperature in c

Cw=coefficient of wind velocity

=0.078=0.0034V-0.0000038V

Where V =mean wind velocity at 5m above the ground km/day

Ch=coefficient of relative humidity

=1.25-0.0087H-0.75*10H -0.85*10 H

H=mean percentage relative humidly at noon

Ca =coefficient elevation

=0.97+0.0098E

E =elevation 100m

Cs =coefficient for percentage a possible sun shine

=0.542+0.0085-0.78*10 S +0.62*10 S

S=mean sun shine percentage

Where

ETO =reference evapotranspiration in mm /day

C= constant to convert units from kg /m /s to mm/day

RN= net radiation at the earth’s surface in kg /m

= (1-r) Rs-Rnl

Where r=lobed=0.23(gross)

Rs= (0.25+5n/N) Ra

Ra =extraterrestrial radiation

Rs=short wave radiation

RnL=long wave radiation

=

=



3. Modified Penman Method

For area measured data’s on temperature humidity sunshine duration or

radiation are available ,the pen man adopted the method use mean daily

climate data ,since day& night time whatever condition considerably affect

level ET an adjustment for this is included. The Modified Pen man equation.

ETO= (W*RN+ (1-W)*+f (U)*(ea-ed)

Where W*RN=radiation term

(1-W)*f (U) (ea-ed) =aerodynamics term

ETO=referee crop evapotranspiration, mm/day

W=temperature relative weight factor

Rn=net radiation in equivalent evaporation, mm/day

f (U) =wind related function.

(Ea-ed)=difference between the saturation vapor pressure at mean air

temperature, the mean actual vapor pressure of the air, m bar

C = adjustment factor to compensate for the effect of day & night weather

condition

4. Pen man-Monteithe method (direct estimate of ETO)

Penman equation has been adopted to estimate evapotranspiration in

mm/day as follows.

ETo =

Where; ETo = reference evapo transpiration, mm/day

Rn = net radiation at the crop surface, Ms/m /day

G = soil heat flux density, MJ/m /day



Tm = mean daily air temperature at 2m height, °c

U2 = wind speed at 2m height, m/s

Es = saturation vapor pressure, kpa

Ea = actual vapor pressure, kpa

Δ = slope vapor pressure curve, kpa/ °c

γ = psychometric constant, kpa/°c

Steps used to calculate Penman-Montith method

U = U *( , U = wind speed in km/day

z = elevation from sea level, m

2. Atmospheric pressure

P = 101.3*( , kpa

z = elevation above sea level, m

3. Mean temperature

Tm = , °c

4. emax = 0.6108*exp ( , kpa

5. emin = 0.6108*exp ( , kpa

6. es = , kpa

7. Δ = , kpa/° c

8. ea = , RHm = relative humidity in %

9. γ = 0.665*10 *p

10. Ra = extra terrestrial radiation in mm/day, from table

11. N = maximum possible sunshine, hr



12. Rs = (a + b* Ra, a = 0.25 & b = 0.5

13. Rns = (1-α)*Rs, mm/day, α = 0.23i

14. Net log wave radiation

Rnl = δ*Ta *(0.34-0.14* )*(0.1+0.9* )

δ = Stefan Boltzmann constant

= 2.01*10 mm/day

15. Rn = , MJ/m /day

16. Sun shine heat exchange from the surface to the soil

17. G month i = 0.07*(Tm monthi+1 -Tm monthi-1), MJ/m2/day

+

From the above five method s for determination of ETO because of Blane-

Criddle & Thornthwaite method use temperature data mix so that other

climatic condition all ignored Hard grave’s and modified pen man method

are over estimated .

The pan –man Monteithe method is done using the comparative soft ware

crop watt window 4.3 as follows for variable climate data.

Country: Ethiopia Station: Gelana

Altitude: 1300 meter(s) above M.S.L.

Latitude: 6.08 Deg. (North) Longitude: 37.90 Deg. (E)

Table 3.4 ETO to determine using pen man monteithe method

Arba Minch station is taken to calculate ETO, because the same climatic

Condition with the command area.

Month Max

tem(c)

Min

tem(c)

Humidity Wind

speed

m/s

Sun

shine

hrs

ETO

mm/day

Jan 31.4 14.29 51.8 95.0 9.09 4.51



Feb 32.57 15.22 47.9 103.5 8.83 4.96

March 33.6 16.16 52.47 121.0 8.10 5.19

Apr 30.61 16.47 63.51 129.6 7.33 4.77

May 28.73 16.15 69.02 155.5 7.85 4.58

Jun 28.02 16.23 64.19 164.2 6.41 4.30

July 27.50 16.83 63.26 155.5 4.77 3.97

Aug 28.41 16.26 59.87 155.5 5.45 4.35

Sep 26.65 16.11 60.06 138.2 6.86 4.67

Oct 29.56 15.66 65.84 103.5 7.60 4.38

Nov 30.15 14.04 60.20 95.0 9.13 4.41

Dec 30.83 13.89 53.71 95.0 9.14 4.34

Sample calculation by manually

Month - Jan a = 0.25

Latitude = 6.08 0N b = 0.5

Elevation (z) =1300m for most crop

Tmax = 31.440 c Ta = Tmean + 273 = 294°k

Tmin = 14.290 c RHm = 51.80%

Tmean=22 .870c U2 = 1.1 m/s

N = 9.09 hrs

1. Wind speed, U2 = 1.1 m/s

2. Atmospheric pressure = 101.3 * {(293 - 0.0065 * z)/293} ^5.26, kpa

= 101.3 * {(293 - 0.0065 * 1475)/293} ^5.26

= 85.04kpa

3. Mean temperature, Tm = =22.87°c

4. emax = 0.6108*exp ( ) = 4.61 kpa



5. emin = 0.6108*exp ( ) = 1.63kpa

6. es = = 3.12 kpa

7. D = 4098*es = 0.189 kpa/°c

(Tm+237.3)2

8. ea = RHm*es = 1.616 Kpa

9. g = 0.665*103*P = 0.0.056 Kpa/oC

10. Ra = 113.46 mm/day……………………………from table3.7 annex- B

11 N = 11.76 hr…………………………………... from table3.6 annex-B

12 Rs = (a + b )*Ra = 8.76 mm/day

13 Rns = (1 - a )*Rs = 6.74 mm/day

14 Rnl = ðTa *(0.34-0.14*ea1/2)*(0.1+ 0.9 ) = 1.98 mm/day

15 Rn = Rns – Rnl = 11.67 MJ/m2/day 0.408

16. G = 0.07*(Tmin (i+1) - Tmin(i-1)) MJ/m2/day

December max =33.83 oc Tmin=13.89 oc &Tmean = 22.36 oc

February Tmax =32.57 oc Tmin=15.22 0c & Tmean = 23.89 oc

G Jan = 0.07*(Tmean (Feb.) –Tmean (dec)) = 0.107 MJ/m2/day

17. ETO = =4.56 mm/daY

3.6 Crop Coefficient (kc)Crop coefficient is used to relate the potential evapotranspiration (ETO) to the

Consumptive evapotranspiration of the crop ETC

ET crop =KC*ETO



The selection of KC depends on the following information &crop date of

growing.Climate data –these are wind speed and humidity length and total

growing season, includes

Initial stage –germination to18% ground cover

Development stage –from 10% to 80% ground cover

Mid stage -80% ground cover to repairing

Last stage –from start, repairing to harvesting

Procedure steps needed to arrive at KC value for different growing stage

are as follows

1. Establish planting or growing date from locale information or from

principal climate zone.

2. Determine total growing season and length of crop development stage

from local information or literatures.

3. Initial stage predication irrigation and rainfall frequency for

predetermined

4. ETO obtained KC value from graph &ETO verses assumed irrigation

interval and plot KC value may be selected from table known humidity

and wind value FAO,33)& (FAO,24)

5. Mid season stage for given climate (humidity and wind) select KC value

(from table FAO,24)

6. Late season stage for time of full maturity or harvesting with a few day,

select KC value from table (FAO, 24) & plot value at end growing season

&full maturity. Assume straight line between KC values at mid -season

period at the end of growing

7. Development stage: Assume straight line between KC values at end of

initial to start of the mid season.



Table 3.5 growing stage & KC value proposed crop.

Growing stage &KC value & proposed

KC

Base

perio

dcrop are

a

Plantin

g date

initial de

v

mi

d

lat

e

initial dev mid late

Maize-

1

40

%

1-mar 20 20 30 10 0.5 0.8 1.0

1

1.0

1

80

Maize-

2

30

%

1-sep 20 35 40 30 0.4 0.8 1.2 0.9 125

Cotton 25

%

30-Jun 30 50 60 55 0.45 0.7

5

1.2 0.9 195

Onion 10

%

15-sep 20 35 11

0

45 0.5 0.6

5

1.0

5

0.7

5

210

Pepper 10

%

15-sep 30 40 11

0

30 0.35 0.7 1.0

5

0.9

0

210

banan

a

5% 1-arch 115 85 11

0

55 1 1.0

5

1.2 1.1 365

Bean-1 30

%

1-arch 20 30 35 15 0.35 0.7 1.1

5

0.9

2

100

Bean 2 20

%

1-sep 15 25 25 10 0.35 0.7

5

1.0

5

0.9

0

75

Source (FAO. 24) (FAO irrigation and drainage paper 24 and FAO irrigation

and drainage paper 33) from appendix crop wat, the total amount of water

that to divert to crops at field level. Gelana irrigation project has two

seasons, the maximum field water supply one of the seasons is selected for

design, because the maximum field water Supply satisfied both of the

seasons.



Field water supply= 0.41l/s/ha *6200 ha=2542l/s

3.7 Irrigation Efficiency.

The amount of irrigation water supplied to the land is not fully utilized for

the growing of crops .this due to various losses now the ratio of the amount

of water available (output) is as irrigation efficiency .it expressed in

percentage to accurate the losses of water increased during convergence

and application to the field an efficiency factor should be include d when

c/c voting the project irrigation requirement project efficiency sub divided

on to the following stages.

1. Conveyance efficiency (EC) - the ratio between the amount supplied

water to the land, amount of water supplied from reservoir.

EC=

2. Field canal efficiency (Eb) the ratio water receives at the field inlet and

received at the inlet of block.

Eb=

3. Field application efficiency (Ea) –the ratio between water directly

available to the field inlet.

Ea=

Project efficiency (KP) the ratio between water made directly to the crop

that release at the head work.

EP=Ea*Eb*Ec

Conveyance (EC), field (Eb) and application (Ea) efficiency criteria

Source ( siyrce FAO, 1978) ICID/ILRI

1. Conveyance efficiency (Ec)

Continuous supply with no substantial change flow.



Rotational supply in project, 3000-7000 hectare & rotational area

EC=0.9

70-300hectarwith efficient management

EC=0.8

Rotational supply in large sachems (>10,000hactar) & small

schemes (<1000hactar) with respective problem, Communication

& less effective management.

Based on predetermine schedule

EC=0.7

Based of advanced request

EC=0.65

2. field canal efficiency(Eb)

Blocks larger than 20 hectare

Eb=0.8 for unlined.

Eb=0.9 for lined or pipe

Block up to 20 hectare

Eb=0.7for unlined.

Eb=0.8 for lined or pipe

3. Filed application efficiency (Ea)

0.55 light soil

0.7 medium soils

0.6for heavy soil

For Gelana irrigation project, has been selected

Eb=0.8 for unlined &

Ea= 0.7 Medium soil.

EC=0.7

Project efficiency (EP) =0.80*0.7*.07=0.392



3.8 Irrigation SchedulingIrrigation scheduling is the schedule in which water is applied to the field.

The schedule of irrigation can be field Irrigation scheduling and Field

irrigation supply scheduling.

3.8.1Field Irrigation ScheduleIt is practiced at the field. The two, parameter of irrigation scheduling.

a)Root depth (D)Rooting depth is that depths of soil in which plant root

penetrate & extract moisture& nutrient for its growth rooting depth

increasing with increasing in the age of the plant crop water requirement

are largely govern by the root zone depth.

The depth irrigation (d) is given by

Dnet = As*D (FC-Pwp) *P

Where Dnet=net depth (m)

AS=apparent specific gravity of soil

D=effective root zone depth (m)

FC=water content of soil at FC

Pwp= water content of soil at Pwp

P=depletion factor

Due to the application losses such as deep percolation and run off losses,

the

total depth of water to be applied will be greater than the net depth of

water.

The gross depth of application (dgross)

Where Ea=field application efficiency and other are as defined above.

a) Depletion factor (P)



Depletion factor is the fraction of available soil water that can be depleted with

Out Causing, soil water deficiency.

Yield response factor (KY)

The response of yield, to water supply in quantity through the yield

response Factor this related yield decrease (1-ya/ym) to relative

evapotranspiration deficit (1-ETa/ETm).

Where ETa=actual evapotranspiration

ETm=maximum evapotranspiration

Ya=actual yield

Ym= maximum yield

(1-

b) Irrigation interval (I)

It is the gap in day between two successive irrigation applications.

Where ET Crop peak =the peak rate crop evaportrapiration, mm/day and

other are defined above.

3.8.2 Field irrigation supply schedulingThis is the schedule of water supply to individual field. It is the schedule of

the total volume of water to be applied to the soil during irrigation is

expressed that



Where q=application rate l/sec

t=application time

Ea= application efficiency

P=depletion factor

AS=application specific gravity

A=area of field

D=effective root zone depth (m)

Qt= indicate the total volume of water applied to field during irrigation at

the head of the field. But the total volume water diverted at head work will

absolute be greater than this value since there is loss of water during

Conveyance and Distribution channel.

The volume of water to be diverted is given by

Where Q=flow rate at head work/sec

Ep=project efficiency

3.8.3 Method of water Delivery and Delivery SchedulingThe objective of water delivery and distribution system is to deliver water

adequately, efficiency and reliably to the required farm level. The system

must deliver the required water that comes sustain the field crop with

irrigation interval (T).



CHAPTER FOUR

3. DESIGN OF IRRIGATION APPILICATION SYSTEM

4.1 GeneralWhen the rain fall of area is not enough to satisfied crop water demand, additional water has to be applied from available water source based on their quality for irrigation proposes to get the expected crop. Three main types of water application 1) Sprinkler irrigation 2) Trickle irrigation 3) Canal (surface water) irrigationThe implementations depend up on the economy, type of crop to be grown, type of soil, climatical condition and topography of area to be irrigated. For Galena irrigation project we proposed canal (surface) irrigation. Due to the following reason.

Low capital investment Cultivation easer in medium loam soil Successfully used in irrigation like crops cotton, maize, &

vegetable etc.

4.2 Surface Water ApplicationSurface irrigation refers to broad class of irrigation in which the soil surfaces convey and distributed water over the irrigated field at the same time infiltration in to under laying profile. As the crop to be irrigated, the soil and topography of our project area necessary the use of furrow irrigation, we managed to design this system alone for crops.



4.2.1 Furrow IrrigationFurrow irrigation refers to water that is into as runs down sloping channels which are cut or pressed into the soil. Design could be accepted if water application efficiency is greater than 60%-70%, with less than 10% deep percolation and 20% run of loss, while storage efficiency is greater than 85 to 95%.Most crops could be irrigated by furrow and is best suited to medium to moderate fine texture soil will relative high holding capacity and conductivity.

4.2.2 Design of Furrow Irrigation SystemTo be best efficient irrigation by furrow method is obtained by selecting proper combination.

- furrow spacing- furrow length- furrow slope- suitable size of irrigation stream- Duration of water.

1. Furrow SpacingSpacing depend on up on type of crop grown and type of machine used for planting and cultivation. Crop like maize and potato are placed 60 to 90cm apart and vegetable (carrot, anion, lettuce) crops are selected 30 to 40cm. while fruit crops are required wide spaced, generally more than one furrow between crop rows.

Table 4.1 Spacing between crop row and plant.(FAO,24)

Crop Spacing between row and plant

Peppers 80*30cm

Onion 60*40cmMaize 75*40cmBean 100*50cmBanana 200*200cmCotton 85*50cm 2. Furrow Length – the optimum length furrow is usually the longest furrow so that can be safe& efficient irrigate. the length furrow which can be efficient irrigated As short as 45m on soil which take up water rapidly or



as much as 300 m longer On soils with low infiltration rate .the length of furrow limited by size & shape of the field

Table 4.2 Furrow length suggested maximum lengths of cultivated furrow (m) for different slope are depth of water applied (A.M. Michael, 1978)

Furrow slope %

Average depth of water applied(mm)75 150 225 300 50 100 150 250 50 75 100Clay Loam Sand

0.05 300 400 400 400 120 270 400 400 60 90 1500.1 340 400 470 500 180 340 440 470 90 120 1900.2 370 470 530 620 120 370 470 530 120 190 2500.3 400 500 620 800 280 400 500 600 150 220 2800.5 400 500 580 750 280 370 470 530 120 190 2501 280 400 500 600 280 300 370 470 90 150 2201.5 280 340 430 500 220 280 340 400 80 120 1902 220 270 340 400 180 280 300 340 60 90 150

3. Furrow Slope – the slope on grade of furrow is important because it control the speed at which water flow Dow furrow. A minimum furrow grade 0.05% is needed to ensure quick surface drainge.the following slope are suitable for different type of soilRecommended slope

Sand loam to sandy soil 0.25%-0.6%Medium loam soil 0.0.2%-0.4 %( for Gelana project)Clay to clay loam soil 0.05%-0.2%

Source (A.M.Michael, 1978) slope recommended for border apply to furrowalso.

4. Furrow Stream – the size of furrow stream the one factor which can be valid after furrow irrigation system has been instead. The size of furrow



stream usual varied from 0.5 to 0.25l/season. We use the general guide line for slop which has been developed by Furrow in flow is given by infiltration rate which for depend on soil texture.

4.3 Table furrow infiltration and inflow rate.

Soil texture Infiltration rate(mm\hr)

Furrow inflow(l/s/1000m) length

Clay 1-5 0.03-0.15Clay loam 5-10 0.15-0.3Silt loam 10-20 0.3-0.5Sand loam 20-30 0.5-0.8Sand 30-100 0.8-2.2

United state soil conservation service (1983)Application DepthThe depth of water applied per irrigation .it can be calculated from cropwat. Opportunity timeThe difference between the time at which water front reaches a particular point along the furrow and the time the tail water recedes from the same point.Advance time (TA) the time at which the advanced water reaches a particular point.Furrow stream (q) the size of furrow stream is one of the factors which can be varied after the furrow irrigation system has bean installed. The size of the stream varied from 0.2l/s to0.3l/s the maximum non erosive flow rate in furrow is given by the following formula

qm=0.6/s=0.6/2=0.3l/s

Where qm= maximum non erosive flow rate (l/s) S=slope of furrow expressed in percentFor Gelana irrigation project recommended parameter for alluvial loam soil. Intake family=0.6 Slope =0.2%-0.4% (we use for calculation 0.4%)

Table 4.5 Values of constant and advance coefficient for different intake families

Soil type Intake family

a b c F g



Very heavy clay

o.5 0.5334 0.018 7.0 7.16 1.088*10-4

heavy clay 0.1 0.6198 0.661 7 7.25 1.251*10-4

Moderateheavy clay

0.15 0.7110 0.683 7 7.34 1.414*10-4

Very heavy clay loam

0.2 0.7772 0.699 7 7.43 1.578*10-4

Heavy clay loam

0.26 0.8534 0.711 7 7.52 1.741*10-4

Moderateheavy clay/light clay loam

0.3 0.9246 0.720 7 7.61 1.904*10-4

light clay loam

0.35 0.9957 0.729 7 7.7 2.067*10-4

Very light clay loam

0.4 1.0810 0.736 7 7.79 2.230*10-4

Very fine silty

0.45 1.1300 0.742 7 7.88 2.393*10-4

fine silty 0.5 1.1960 0.748 7 7.79 2.556*10-4

Moderate fine/coarser silt loam

0.6 1.3210 0.757 7 8.15 2.883*10-4

coarser silt loam

0.7 1.4430 0.766 7 8.33 3.209*10-4

Very coarser silt loam

0.8 1.5600 0.773 7 8.50 3.535*10-4

Fine sand loam

0.9 1.6740 0.779 7 8.68 3.862*10-4

coarse sand loam

1 1.7860 0.785 7 8.86 4.188*10-4

Fine sand 1.5 2.2840 0.799 7 9.78 5.819*10-4

coarse sand

2.0 2.7530 0.808 7 10.56 7.451*10-4

For design we use furdev computer programme see the results each crops in annex- A

Table4.6 Summarized furrow design by furdev soft ware



Tt min Tn min

Ti min Tav min

Fav mm

Fg mm

RO mm

DP mm

Ea%

Onion 934 86 1020 103 30 39 8 3 70

Maize 3631 373 4064 432 60 84 19 7 70

Pepper 869 148 1017 234 40 41 2 11 70

Bean 1663 366 2029 578 61 63 2 17 70

cotton 2157 367 2524 547 69 74 5 17 70

Where Tt= advance time Tn= net opportunity time Ti= design inflow time Tav= average opportunity time Fav= average intake design Fg= groos application RO= surface run off DP=deep percolation

CHAPTER FIVE

5. ALIGNMENT & DESIGN OF CANAL & CANAL STRUCTURE

5.1 General A well designed distribution system consisting of a net work canal is required to take away water from the canal head works such as weir,barrage,reserviour or storage dam to the field .based on the water requirement of the crop on the area to be irrigated the entire system of the main canal, secondary canal, tertiary canal &field distribution should be design properly for a certain realistic value of peak discharge that must pass through them to provided sufficient irrigation to the commands



5.2 Canal AlignmentIn relatively plan areas it should attempt to align the main canals along ridgeline between adjacent valleys. Branch canal &distribution May also be aligned along the ridge lines of secondary valleys .this

configuration reduced the need for costly cross drainage works &facilitate the construction of drainage canal along the lowest lying areas ,how ever this would increase the number of drops in the main canal, thereby reducing the gravity command able area .It is therefore, preferable that the main canal would follow the highest possible counter with minimum slope where as secondary& tertiary canals are suggested to be either along or across the contours to mach the topography,sothat finally the field canals are aligned across & the furrow along the counter canals should be as straight as possible because Sharpe curve lead to scour on the out side &siltation on the inner side of the canal, thereby requiring constant alternation .

In hill area it should be design so as to balance cut &fill earth work as far as possible for economy reason .but canals in high fill area more difficult to construct ion &would in genera high loss of water by seepage for this reason when ever possible the whose canal section is preferable if it is in cutting.

5.3 Hydraulic Design of CanalA canal is said to be designed when it’s longitudinal and cross sections are worked out to suit requirements. Thus various canal dimensions for example bed width, depth said slop, longitudinal slop are to be fixed in design of irrigation canal. Irrigation canal are designed to take maximum required discharge safely which is called full supply discharge. Since there is Adam 30 Km before diversion head work, it is considered that sufficient water is available. So the canal is designed for continuous supply system. soil of Galina is alluvial, this type of soilis formed by transport of different soil particle. Based on arbitrary particle size Kennedy propose critical velocity ratio (m).

Table 5.1

Sedment type critical velociti ratio mlight sand 0.9-1.1sandy,loam silt 1.2hard soil 1.3



Where m=v/v. m critical velocity ratio

v flow ratev. critical velocity

5.3.1 Design DischargeDesign discharge in the maximum flow that the canal carry at all season to fulfill the water demand of cops. The net scheme Irrigation requirement has been found to be 0.41 l/sec/ha.The FSL of MC1that is found at the right bank of Gelana river is 8.205 m3/s where as 1.78 m3/s of MC2 at the left bank.Available data

FWS max=0.41 l/sec/ha Total command area=6200ha Conveyance efficiency=0.7 Field canal efficiency=0.8 Future expansion=10% Working hour=12hr

Qd= (Fws*area*time factor*future exp)/(project efficiency)

=0.41l/sec/ha*6200ha*1.1/ (0.7*0.8)

Qd=9.98 m3/s

5.3.2 Permissible Velocity

It is the maximum mean velocity that will not cause erosion of the canals body. There commended permissible velocity for living material and soil type is tabulated blow

Table 5.2 permissible velocity

Type of soil Maximum permissible velocity

Ordinary soil 0.6-0.9

Very light loose to averaged 0.3-0.9



sandy soil sandy loam black cotton soil

Murum,hard soil 0.9-1.8

Gravel or rock (disintegrated) 1.5

Teble 5.3 maximum permissible velocity

Type of lining Maximum permissible velocity(m/s)

Boulder lining 1.5

Brick tile lining 1.8

Cement concrete 2.7

5.3.3 Roughness Coefficient (n)Roughness coefficient is depending up on the roughness of the canal boundary. For the soil of Gelana project that is alluvial estimated roughness coefficient is 0.0225 if the canal types in fair and for the lining material different value of n is tabulated

Table 5.4 manning coefficient

Material Coefficient(n)Wood 0.013-0.165Steel 0.0125-0.018Concrete 0.013-0.018Masonry 0.02-0.036Earth 0.0225-0.035



5.3.4 Canal Side SlopeThe side slop of the canal should be as steep as possible being un stable either wet or dry. For smaller canal in the system side slop 1V:1H has been adopted. The recommended slop for main & secondary canal is 1V: 1.5H or 1V: 2H

5.3.5 Free boardIt is the margin between full supply level (FSL) of canal and bank level. The recommended free board by Lacey’s is FB=0.2+0.15Q1/3

5.3.6 Design of Main CanalThe cross section of the main canal varies as the distance of the canal increases as the design of main canal held by considering the amount of water diverted through the off taking canals up stream of each division of the main canal. For ever topography and rocky area around diversion head work of Gelana irrigation project lined cement plastered masonry type rectangular canal is provided.

Design of lined canalAvailable dataQ=8.205m3/sN=0.014

S=1/800A= BD+MD2 Fig 5.1 Rectangular Canal Efficient section



A =2D2

P=4DR=D/2

Using manning equationQ=A/n*2D2*(D/2)2/3S1/2

D= (Q*n/1.26*S1/2)3/8 = (8.205*0.014/1.26*(1/800)1/2))3/8

=1.43mA=2D2 2*1.432 =4.1m2

P=4D =4*1.43 =5.72mR= A/P = 4.1/5.72 = 0.715mV=1/n*R2/3*S1/2 =1/0.014*(0.715)2/3*(1/800)1/2

= 2m/s OKB =A/D = 4.1/1.43 =2.87m

Design of unlined canal

Using Kennedy theory

V0 =0.55 *MD0.64

Q=8.205 D=1.43n =0.0225 Z =1.5m =1.2 B=2.87Design calculation B/D =1.76*Q0.35

B/D =1.76*(8.205)0.35

A =BD+ZD2

A = (3.7+1.5) D2 =5.2D2

P = B+2D SQUAR ROOT (Z2+1) = (3.7+3.6) DP = 7.3DR = A/P =0.71D

From continuity equationQ = AV8.205 =5.2D2*0.55*1.2D0.64

D=[8.205/3.416]1/2.64 =1.39R=0.71D =0.71*1.39 =0.987V0 = 0.55*1.2*1.390.64 =0.815m/s



V = C*ROOT (RS)C = 1/n +23 +0.00155/S 1+ (23+0.00155/S) n/root(R)

Assume 0.00155/S =0 for the 1st trial

C= )*

V =0.82=0.815V=Vo…..ok MC1

Chinage(m)Discharge D B FB S V

0+0-8+00 8.205 1.43 2.87 0.5 1.25*10-3 26+00-8+00 8.205 1.6 3.2 0.5 6.67*10-4 1.68+00-3+600 8.205 1.39 5.14 0.5 3.9*10-4 0.814+600-5+600 7.49 1.63 4.84 0.5 3.5*10-4 0.85+600-8+00 6.065 1.28 4.22 0.47 3.7*10-4 0.778+00-10+400 4.64 1.18 3.54 0.45 4.6*10-4 0.7310+400-12+600 2.86 0.103 2.62 0.41 3.9*10-4 0.6712+600-16+600 1.43 0.83 1.66 0.37 3.6*10-4 0.61

MC2

ChainageDischarge D B FB S V

0+1400 1.78 0.63 1.24 0.5 5.0*10-3 2.21+00 1.78 0.91 1.82 0.4 4.3*10-4 0.63

Secondary canals of Mc1

Mc1Sc1 0.713 0.67 1.04 0.25 4.8*10-4 0.52



Mc1Sc2 1.43 0.83 1.66 0.37 4.4*10-4 0.59Mc2Sc3 1.43 0.83 1.66 0.37 4.4*10-4 0.59Mc2Sc2 0.878 0.72 1.21 0.25 2.9*10-4 0.63Mc2Sc2 0.09 0.33 0.33 0.2 5.25*10-4 0.59Mc2Sc3 0.814 0.70 1.15 0.25 4.6*10-4 0.52

5.3.7 Tertiary CanalsTertiary canal are also designed as main and secondary canals using Kennedy theory. Since the canals are designed along the contour a minimum of drop structure required. They are off taking using canal outlet from secondary canals and distribute to the field canals in the same manner.

5.4 Canal Structures 5.4.1 Expansion Transition.A canal transition is a gradual change in the cross section of a canal flow from one uniform state to another. After the end of rectangular canal expansion transition is provided to join trapezoidal unlined canal. There are three types of design method Hindus design method is recommended for deferent depth of flow. Where Bt=width of trapezoidal Br=width of rectangular

Br Bt Fig 5.3

DesignsAvailable dataFSL at exit=1295.0Bt=5.14mDt=1.39mBr=2.87mDr=1.6mQ=8.205m3/s



Splay in expansion 3:1Z=1.5:1

C. Design Procedurea) velocity at exit area of flow

A= (Bn+ZDn) Dn = 95.14+1.5*1.39)1.39 =10.04V =Q/A =8.205/10.04 =0.82m3/s

Velocity head hv Hv =V2/2g =0.822/2*9.81 =0.034TEL4.4 =FSL+hv=1295+0.034 =1295.034m.Beginning of expanding transition A=(Bf+Df) =1.87*1.6 =4.59m2

V =Q/A =8.205/4 .59 =1.78m/s Hv =V2/2*g =1.78/2*9.81 =0.163m.Loss of head in expansion transition =0.3(V3

2 - V42)/2g=0.3(1.782 - 0.822)/2*9.81

=0.038TEL3-3=TEL4-4+hL

1295.034+0.038=1295.078 Water surface and bed level WS3-3=TE3-3 - V^2/2g 1295.072-1.78^2/2*9.81 =1294.91 BL3-3=1294.91-1.6 =1293.31 WS4-4=1295.034-0.82^2/2*9.81 =1295BL4-4=1295-1.39= 1293.6

Water surface profileExpanding transitionL=3(Bn-Bf)/2 =3(5.14-2.87)/2 =3.4052x=3.405X=1.7032y=FSL-WSL3-3



=1295-1293.31 =1.69Y =0.845C=Y/X^2 =0.845/1.703^2 0.29Y=0.29X^2

Table 5.5 cross section of transition

X 0 0.25 0.5 0.75 1 1.25 1.5 1.703

Y 0 0.018 0.073 0.16 0.29 0.45 0.65 0.841

5.4.2. Drop Drop structure is constructed on a canal to lower down the water level and the bed level of the canal to minimize the potential. It is therefore designed to dissipate the energy, but it has to be resist the scoring effect. For discharge less than 8m^3/s vertical drop is best and economical.

Sample calculationAvailable dataQ=7.49m^3/sB=4.84mHl=1mD1=D2=1.36mDesignq= Q/B =7.49/4.84 =1.55m^2/sV=q/D =1.55/1.36 =1.14m/sYc= (q2/g)1/3

= (1.552/9.81)1/3

=0.65ha=v2/2g =1.142/2*9.81 =0.07E=D + ha-p =1.36 + 0.07 -0.2 =1.23mThe dimension of the cistern



It is determined asX= Yc/2 = 0.63/2 = 0.32Lc= 3*(H*E)1/2

= 3*(1*1.23)1/2

=3.3W= 18.46Q1/2/(q + 9.91) =18.46*7.491/2/ (1.55 + 9.91) =4.4m

Where X =depth of cistern Lc = length H = drop heigh W = width

E=1.23 YcD1

P

Z=1 D2=1.36

X=0.32

Lc=3.3

Fig Drop structure

Table 5.6 drop components tabulated blow



Q m3/s D (m) B (m) P (m) H (m) X (m) Lc (m) W (m)8.205 1.39 5.14 0.2 1 0.32 3.3 4.4

7.49 1.36 4.84 0.2 1 0.3 3.3 4.4

6.063 1.28 4.22 0.2 1 0.3 3 4

4.64 1.18 3.54 0.2 1 0.28 3 3.54

2.86 1.03 2.62 0.2 1 0.25 2.8 2.8

1.43 0.83 1.66 0.2 1 0.21 2 2

5.4.3 CulvertConveyance culvert is a structure built in conveyance system at the intersection of irrigation or drainage canal and road. The fundamental objective of the hydraulic design of culvert is to determine the most economical diameter at which the design discharge flow safely the following limitation is recommended. Maximum velocity = 1.5m/s A farm road =6m A minimum diameter of pipe =0.6m

Available data

Q=0.814m3/s L=6m H=0.15mAssume D=O.9m

Q=C*A

C= (1.1+ )-0.5

C=0.857

A=

=0.636Q=0.885*0.36(2*9.81*0.15)1/2

=0.966 m3/s > 0.814 m3/s ok



V =Q/A =0.966/0.636 =1.48 m/s ok

5.4.4 Division BoxDivision structures or box regulate the flow from one canal to other, or to several other canals they usually consist of box with vertical wall in which Controllable opening may provided.DesignAvailable dataQ=1.783/sQ1=0.09m3/sQ2=0.878 m3/sQ3=0.814m3/sAbroad crust formula is used to divide proportionallyQ=C*L*H3/2

= where Q=discharge over rectangular sill

C=coefficient discharge=1.77 L=effective length H=over flow depth=0.4mAssume sill hieght0.2m&dead height 0.2mL=3.94mL1=0.2mL2=1.84mL4=1.96m

5.4.5 Canal OutletCanal outlet is structure built on the bank of distributaries canal through which Water is supplied to water course. Semi modular outlet is selected for this project.b/c it is simple and discharging free pipe outlet is preferred. In practice, the pipe outlet is generally set at the level lower than 0.3D and therefore it acts as a Sub-proportional outlet because the head over the out let is increased. Pipe outlet is provided on tertiary and field canal where as division box gated rectangular outlet on the secondary canal. in canal outlet of chapter seven.

DesignAvailable dataQ=0.358 m3/s



D=0.38m C=0.62 (discharge free)h<=0.3*D <=0.3*0.83 =0.24Take h=0.21m Q= C*A*(2gh)1/2

0.358=0.62*A*(2*9.81*0.21)1/2

A=0.284m2

A= d2/4d =(4*0.284/ )1/2

=0.6mTake d =0.60.358= 0.62*x*0.62/4*(2*9.81*h)1/2

h= 0.21m ok Therefore provide 0.6m diameter pipe at a working head of 0.21m.



CHAPTER SIX

6. DRAINAGE

6.1 GeneralThe processes where by surplus water is removed from the land. It includes both internal drainage is the term applied to systems for dealing with excess water that describe all of soil and the collection and dispersal of surface runoff. By its nature, irrigation creates periodically saturation condition of upper layers of soil formation over a long period where intensive irrigation is practiced; even deep soil layers tend to become saturated and consequently underground water table rises in absence of adequate drainage facilities. The knowledge of drainage engineering is very essential to solve this problem. Waterlogged land is of little use; however, it can be utilized after providing proper drainage arrangement. Usually in undulating country, the surface slopes are sufficient to carry off this surplus water into the ditches and stream without any engineering construction. Low lying flat areas are usually invariably near or below the flood level of the river. In order to prevent the area from flooding the river must be trained; it is usually done by constructing of embankments. Like this, we must construct drainage canal in order to prevent the irrigation canal from silting.

6.2 Selections of Drainage SystemsDrainage may be artificial or natural. Drains are termed artificial when they are constructed after proper consideration of existing conditions and function to be served. Artificial drains are generally constructed to dispose off surplus water quickly, before it gets absorbed deep into the soil. Drainage can be classified into two main systems.



Those are:1 -Surface drainage system

2 -Subsurface drainage system

6.2.1 Surface Drainage SystemsSurface drainage problem occur in nearly flat area, uneven land surface with depression or ridges preventing natural runoff and in areas without outlet. Soils with low infiltration rates are susceptible to surface drainage problem. Surface drainage is intended for safe removal of excess water from the land surface through land shaping and canal construction. Function of the system may be considered as:

-Collection systems -conveying systems-Outlet system

6.2.2 Subsurface Drainage System Subsurface drainages are required for soils with poor internal drainage and a high water table. This type of drain does not hinder movement in the field but they have high initial investment cost. Water from the individual field is collected and is then removed through a system to the outlet. Generally, surface drainage is required for-1. The removal of storm rainfall where the subsurface drainage is noteconomically feasible 2. The collection and disposal of surface irrigation runoff3. The collection and disposal of drainage in deltaic area

6.3 Design of Surface Drainage Canals Mean annual rainfall (MAR)MAR is the average of the total yearly rainfall of long year record For this project the mean annual rainfall of GELANA is taken and is found to be 906.8mmTable 6.1 Max side slope for drainage canal


Soil type Sandy, Soft clay 3:1Sandy clay, Silt loam 2:1Fine clay, Clay loam 0.5:1


6.3.1 Drainage coefficient (DC)The drainage coefficient is the amount of water that must be removed from soil surface in order to have sustainable agriculture. It depends, on depth of irrigations, method of irrigation, leaching requirement and soil characteristics. There are different methods for estimating drainage coefficient. Those are: #1 10 %MAR method Where: MAR= mean annual rainfall For GELANA irrigable area, MAR =906.3 mm DC = 1 %906.3mm DC = 9.063mm #2 Hudson (1983)’s method In this method the following two conditions are considered

If MAR <1000 mm, DC = 10 mm/dayIf MAR >1000 mm, DC = MAR/100 mm/day

Since MAR =906.3 mm, DC=9.063 mm/day#3 Muzumdor methodsIn this method, the following table is provided for estimation of drainage coefficient from MAR.

Table 6.2 Estimating of drainage coefficient

MAR(mm) DC(mm)

1 <750 5.0 - 7.5

2 750 -1000 7.5 - 9.0

3 1000 -1250 9.0 - 12.04

1250 -1500 12.0 - 25.0For GELANA Project case D.C = 906.3/100=9.063mm/dayThe capacity of the drainage canal is determined based on the area coverage of tertiary and field distributes canals.From different types of drainage canals, the trapezoidal drainage canal is selected. The reason is that trapezoidal canal is more economical than the other canals.



Design of field drainAvailable data

Drainage area Adr =32ha Roughness coefficient n=0.04 Drainage coefficient DC =10mm/day Drainage Discharge Qdr =Dc*Adr

=10mm/day*32ha =0.037m3/sec

Slope of field drain is determined from top map. S= 1/500 =0.002

Side slope m=2 Manning roughness coefficient now from manning equation.

Q =1/n*AR2/3*s1/2

For trapezoidal canal:First by assuming D =0.4The area of drain section is given by B=2*D*tan (26.565/2) =0.472*D A =B*D+mD2

=2.472*D2

P =B+2*D* =4.944*D

R =

R =

=0.499*D

V = *R2/3*S1/2

=0.7046*D2/3

Q =A*V =2.472*D2*0.7046*D2/3

=1.74*D8/3

By try and errorD =0.24 mB =0.113m

Free board (FB) The top of canal banks has to be maintained higher than the level to allow for waves and possible fluctuation in supply. The vertical distance between the top of drainage canal banks and the full supply level of drainage canal,



known as free board. For our case take free board 0f 0.2m.

Design of tertiary canal Data available Drainage area Adr =96haDrainage coefficient =10mm/dayBed slope =1/800 =0.00125 from top mapRoughness n=0.04Drainage discharge Qdr =A*Dc =10mm/day*96ha =0.111m3/secB =2*D*tan (26.565/2) =0.472DA =BD+mD2

=2.472*D2

P =B +2*D*

P =0.472+2*D*P=4.708*D

R =A/P R =

=0.525*D

V = *R2/3*S1/2

=0.556*D2/3

Q =A*V =2.472*D2* 0.556*D2/3

=1.37644*D8/3

By tray and error D=0.4from this B =0.188m

Design of secondary drainage canal Available data.

Drainage area Adr =230ha Drainage coefficient Dc =10mm/day Bed slope S=O.OO1015 Roughness coefficient n=0.04 Drainage Discharge Qdr=Dc*Adr

=230ha*10mm/day =0.2662m3/secThe area of drain section is given by A = BD +mD2

B =2*D*tan (26.565/2)



=0.472*D A =0.472*D*D+2*D2

=2.472D2

P=B +2*D*

P=0.472+2*D* P=4.708*D

R=A/p =

R=0.499*D

V = *R2/3*S1/2

V =0.5D2/3

Q =A*V =1.236*D8/3

By tray & errorD =0.565mB =0.267m

Design of main canal Data available Drainage area =442ha.Drainage coefficient =10mm/day.Bed slope =1/1000Design discharge Qdr =10mm/day*442ha Qdr =0.512m3/sec The calculationB =2*D*tan*(26.565/2) =0.472*DA =BD +mD2

=2.47*D2

P =B +2*D =4.708*DR =A/p =0.5D



V = *R2/3*S1/2

V =0.5145D2/3

Q =A*V =1.272*D8/3

By tray & error B =0.337mD =0.715m

CHAPTER SEVEN

7. HEAD WORK DESIGN

7.1General Diversion head work are those works which are constructed at the head of a canal to divert the river to wards the main canal, so as to ensure a regulate continuous supply water free from silt.wier is an obstruction or a



barrier constructed across a river. The obstruction is of smaller in comparison with the dam. It raises the water level and supply water to off take canal.

7.1.1Location of weirWhen selecting location of weir the following consider1. From the counter map of state farm, the location where the required Head to irrigate the farm is develop2. The selecting site should be economical a) Having short main canal b) River bank should stable c) Should be in straight reach d) Good foundation available at the site e) Site easily accessible by road

7.1.2 Selection of Weir TypeThe weir may be broadly divided in to three:

1. Vertical drop weir this type of weir was used in most case, particularly suitable for consolidated gravel foundation.

2. Rock fill weir is suitable for fine sandy foundation. Such weir requires huge quantity of stone and is economical only when the stone is easily available.

3. Concrete glacis or sloping weir.This type of weir is used on permeable foundation and is generally provided with low crest. In deciding the type of the weir, the following conditions should be considered.

Economy of construction Foundation condition Size of the project Head across the weir and practically during implementation taking all

the above factors & the case for construction & suitability of foundation masonry weir of vertical drop is selected for this particular irrigation project.

7.2 Weir DesignAvailable Data:

Q =115 (refer data from hydrology, Chapter

River bed level=1293.5m (data from top map)Assumed data:



Afflux, =1.0m (Dr.kR. Aroara) Retrogression=0.5m (Source: Dr .kR Aroara) Silt factor, dm=0.232 G=2.24

7.3Hydraulic Design of Weir Determination of the crest level

a) Average level of highest field = 1293mb) Head loss across the field = 0.1 mc) Head loss at the turn out = 0.15 md) Head loss at the head regulator = 0.32 m (Dr .KR..Arora)e) Water depth required = 1.39m(data from canal design part)f) Slope of the canal * distance of the highest point from the weir

= 0.0014* 200+0.000198*3400=0.96 m Therefore, the crest level of the weir=1293+0.1+0.15+0.32+1.43+0.96 =1296.OO Weir height = Crest Level of the Weir – River Bed Level =1296.0-1293.5=2.5m

7.3.1Water WayIt should be adequate to pass the design flood safelyL=4.75*Q0.5

L= 4.75*(115)0.5=50.93m say 51 mLoosen factor for boulder reach between 0.45-1m (Dr .KR.Arora) take =0.50.50=le/51Le=26 mDischarge intensity (q) = Q/Le=115 m3/s/26=4.42m3/s/m

He= where He=Head over

the crest Q=Design flood discharge Le=26m C=coefficient of discharge=1.70

He=

=1.89 m

U/S TEL=1296.0+1.89



=1298.84m Regimes scour depth(R)

R=1.35 where q=Q/L=115/26=4.43

and f=1Where, mr is average particle size of riverbed at weir site in our case, the available material at weir site is formed of gravel course. mr=0.323 (from table) f=1.76 =1

R=1.35

=1.35 =3.63

Regime velocity (Va) =q/R Va=4.42/3.3.63=1.22 m/s Velocity head (ha) =Va /2g=1.22 /2*9.81=0.10m U/S HFL =U/S TEL – ha =1298.84 – 0.10 =1298.74 m Down stream (D/S) HFL =U/S HFL – Afflux =1298.74– 1.0 =1297.74 m D/S HFL before construction=D/S HFL – Retrogression =1297.74– 0.5

=1297.24 m

7.3 Design of Weir WallThe weir wall is proposed to be trapezoidal cross-section with u/s face vertical and d/s face with slope 1:2.Depth of water over crest =u/s HFL-crest level

d =129.74.5-1296.95=1.79m

7.3.1 The top width of weir wall (B )

1) B = =1.12m where, B = Top width of weir wall

Generally 1.5 to 1.8m (source Garge) 2) = s+1=0+1=1 3) =3d/2G=1.13m Adapt 1.5m



G=Specific gravity of floor material (2.24) Pond level=FSL+ working head (modular)Modular head is equal to sum of head loss in regulatory &head required to pass the fully supply discharge into canal. It usually range from 1.0-1.5 m (Dr K.Arora) FSL=RL highest point from the weir +head loss canal +field loss =1293+.0.15+0.1+1.57=1294.72 m Pond level=FSL+ working head (modular)

=1294.72+1.5=1296.73 mSeepage head=pounding level- river bed level

=1296.73-1293.5=3.23 m

7.3.2 Bottom width of weir (B) The bottom width should be sufficient so that the maximum compressive stress with in allowable limit &tension does not develop.

a) B= where H=Crest weir height

d=depth water above crest

B= =3.9 m

b) No flow condition Hs= H+s=2.5+0=2.5 m

Mo=9.81*2.5^3/6=70.1K-m-------------(a)Mr=w/12*(((G+1.5)H+H*S)B2+a(GH-H-S)B-0.5*a2+(H+2*S))---(b) =0.82(13.09B2+6.51B+3.93Equate M0=Mr 85. 48+3.93 =13.09 B2+6.51B by trial & error B=2.4 m c) High flood condition with weir just submerged Over turning moment Mo=whH2/2

q=2/3 cd (2g) 0.5d2/3

Where cd=0.58 (Dr K ARORA) q=4.42m3/s/md= (4.42/ (2/3*0.58*4.43)2/3=1.90Mo=9.81*1.90*2.52/2=114.16 KN-mUsing moment outer middle the pointMr=Wh (G-1) (B2+Ab)/12 =9.81*2.5*1.24(B2+1.5B)Equate Mo=Mr By trial &error B=4.9 m say B=5m



Take the largest of all B=5 m

7.3.3 Depth of Sheet Piles RL of bottom U/S pile=U/S HFL-1.5R

=1298.74-1.5*3.62=1293.3 mDepth of U/S pile below bed level=river bed-RL U/S pile

d1 =1293.5-1293.30=0.19 Take d1=2 mRL of bottom d/s pile=D/S HFL after regeration-2R

=1297.24-2*3.62=1290 m d2=1293.5-1290=3.5 m

7.3.4 Impervious Floor Seepage head=pounding level- river bed level

=1296.73-1293.5=3.23 mBy Bligh s theory, the total creep length (L) is given by:

L=CHs where, C=Bligh s Creep coefficient taken as (5-9) for grave foundation Let us take C=9 L=9*3.23 =29 Length of downstream impervious floor, l

L =2.21*C

=2.21*9

11mLength of upstream impervious floor, L L =L- (L +B+2d +2d )

=29-(11 +5+2*2+2*3.5) =2m

7.3.5 Protection WorkD/S protection work The total length of d/s floor and d/s protection work is given by

=L +L



=18C

=18*9 =22.4 m

Length down stream protection=L1+L2-L3

=22.4-11=11.4mMinimum length d/s concrete block=1.5d2=1.5*3.5=5.25 say 5mProvided 1m*1m*1m concrete block cover 0.5m thick in filterMinimum length d/s lunch apron=2.5d2=2.5*3.5=8.75 m

Thickness lunch apron= t= * =2.1 m

7.3.6 Up stream Protection Work Minimum length u/s concrete block=1d1=1*2=2mProvided 1m*1m*1m concrete block cover 0.6m thick gravelMinimum length u/s lunch apron=2d1=2*2=4 m

Thickness lunch apron=t= * =1.6m

Thickness of the impervious floor by Bligh’s theory. Seepage head (Hs)=3.23m Creep length (L)=29 m Specific gravity=2.24Residual head at point A the toe of weir wall

H=HS- =2 m

The thickness of D/S floor at this point is then obtained by;

t= 1.33 =1.33*( Provided a thickness of 2.15m

for a length 5mThickness of D/s Floor after 5m from the function of the weir wall.

H=HS- =1.44m

t=1.33 =1.33*(

7.3.7 Check by Khosla, s Theory a) Downstream pile:



b=18, d2=3.5 , =5.71

=38.31%

=26.22% Thickness correction for

=5.52%(-ve) Correction for mutual interference

Correction=-19*

=-19*

=-0.36%(-ve) Corrected =32.72% Percentage pressure at A =

=32.72+

=55.83% Residual head, h=0.5583*3.23 =1.80m

Thickness of the floor = 2.2m………….Ok

Percentage pressure at B

=32.72+

Residual head, h=0.3458*3.23 =1.12m

Thickness of the floor = 1.6m…………….Ok

Hence the floor is safe by Khosla s theory



Checking of the thickness of the floor by Kohsla’s theory Exit gradient

Total length of the impervious floor, b=18m Depth of down stream pile, d2=3.5m

= ,

GE= =0.15 < - ………..ok

Up lift pressureb) Up stream pile

b=18m, d1=2.m, ,

E

,

=70.54%

=29.45%

=20.44% = 79.56%Thickness correction for

=4.51%,t=1m,d1=2

Correction=19*


D

E1

D1

C1 d1=2m d2=3.5

m

FIG 7.1


=19*

=0.07 %( +ve) Corrected =75.12%

7.4 Energy DissipationDuring the flood season, when high flood occurs over the weir crest water falls from the maximum reservoir level of u/s to the d/s tail water and the difference b/n the u/s and d/s energy grade line becomes very high. There fore, the energy must be dissipated before it reaches the natural river source: other wise it causes damage to d/s of the apron. The energy tends to dissipate through a hydraulic jump d/s of the weir .To control the location of the jump stilling basin is designed.

U/S TEL

U/S HFL He=1.89 D/S HFL

D3

2.5mD2

D1

Fig 7.2 Energy dissipation

To determine the water depth of well know Bernoulli’s equation is used consider 0-0&1-1H+He=D1+V2/2*g+HL neglect the HL

2.5+1.89=D1+



4.89= D1+4.422/2*9.81*D12

4.89D12=D13+0.996 by trial &error D1=0.47 m

D2= (-1+ ) where f= =4.39

D2 = (-1+ ) =2.68

Critical depth dc is expressed by using formula

Dc = /g = /9.81 = 1.25

The head loss dissipated energy As result of jump p =HL =

= ( ) = 0.44

The length of jump, Lj= 5(D2-D1) = (2.68-0.47) = 11.05mD3 =d/s HFL –bed level

= 1297.4-1293.5 =3.9m.As D3>D2 the jump occurs on weir face, and there is no need of design stilling basin.

7.5 Stability Analysis of WeirThe design section has to be safe against sliding, over turning & tension requirement .stability analysis of the proposed weir is carried out by considering the various external. Forces acting on it. The external force including. Uplift pressure is considered for the weir wall. Water wedge weight is considered for weir crest only Self weight Unit weight of water and masonry is taken to be 9.81 and 24 KN/m

respectively. Moment is taken about the toe per meter width the effect of this force

acting on design structure varies from place to place, foundation condition of the site height of the design structure.



Ha=0.1 PH3

H1=1.79 PH1

W (H1+Ha)

4.2PH2

1.75 2.5 W1 W2 2 1

W (H2 +Ha) 1.5 3.5 O

4.2

PUFig 7.31 Forces act on weir

Table 7.1 Forces act on weir

No

Item Forces (KN)

Lever arm(m)

Moments at O(KN-m)

Vertical

horizontal

Overturning

restoring

1 W1=1.5*24*2.5 90 4.5 4052 W2=0.5*3.5*1.75*2

473.5 2.33 170.3

3 PU=0.5*5*4.2*9.81 - 3.33 342.43



102.734 PH1=9.81*1.89*2.5 43.83 1.25 54.785 PH2=0.5*2.52*9.81 30.65 0.83 25.46 PH3=1.69*1.5*9.81 24.86 3.35 83.5

TOTAL 85.63 74.65 422.4 658

Safety factors

Overturning stability, Safe

Sliding safety factor, Safe

Check for tension, And for no tension

e=0.25 No tension, ok!

7.6 Design of Under SluiceThis structure has crest at level to develop a deep channel pocket, which will help to bring flow dry weather discharge to wards this pocket, there by ensuring easy division of water in to the canal through the head regulator. This opening will also help in scouring and removing the deposited silt from the under sluice pocket.Designed with the discharge of;1) Twice the discharge of the off taking canal capacity Q=2*8.2=16.4m*3/sec2) 20% of the max. Flood, Q=0.2*115=23m*3/secTherefore, Qsluice will be max. of the above. Qsluice=23m*3/secProviding one under sluice with 2m width (divide wall is provided between the proper weir and the under sluice).

Scoured depth for the sluice section (R)



, for f=1

RL of bottom of scour depth on u/s side=U/S HFL-1.5R=1298.74-1.5*7.07 =1288.14m.Therefore, the depth of the u/s pile, 1293.5-1288.14=5.36m.RL of bottom of scour pile on d/s side= D/S HFL-2R=1297.24-2*7.07=1283.10m.Therefore, the depth of the d/s pile, =1293.5-1283.10=10.4m.

7.6.1 Impervious floor

Min. length of d/s impervious floor,

Where H=Hs=3.23mC=9 (for boulder foundation Dr.K.A.Arora, 2002)

=19.79m 20m.Min. Length of u/s impervious floor,

Therefore, take nominal value of 2m for u/s length.

7.6.2 Protection workTotal length of d/s impervious floor and protection work

Length of the d/s protection work, this length is both inverted filter and launching apron.

Length of the u/s protection work,

Note; using broad crested weir formula,

Where H=weir height + He=3.23+1.89=4.49m.L=2m and Cd=1.7

Discharge through the under sluice.



And Discharge through the proper weir

with length, L=24m.Therefore, the total discharges, ok

7.7 Design of head regulatorIt is provided at the head of the off taking canal and has the following objectives;

1. To regulate the supply of water in to the canal2. To completely shutout the high flood from entering to the canal.3. To control the entry of silt to the canal.The regulation is provided by the gate which is fixed in such a way that, the discharge or desired capacity of water can easily flow in to the intake canal. The intake canal is placed so as the top level should be less than or equal to the crest level of the proper weir. Crest levels1) Under sluice=the crest level of under sluice is equal to the river bed

level=1293.5m.

2) Head regulator=is kept 1.2 to 1.5m higher than the crest level of the under sluice (say 1.5m) =1293.5+1.5=1295m.Bed level of canal=crest level of head regulator-canal flow depth=1295-1.43=1293.57m. Take bed level canal=1293.8mSill canal=bed level canal- river bed level=0.3m

7.8 Design of Silt ExcluderIt is a structure constructed regulate silt from water entering the canalAvailable data Available supply discharge of canal=8.2m3/sCrest level of under sluice=1293.5 mCrest level of head regulator=1295 mBay width under sluice =2mDesign discharge=20% of the canal dischargeQ=0.2*8.2m3/s=1.64m3/sA minimum velocity of 2m/s is usually adapted through the tunnel in order to keep the sediment free from depositV=2m/sArea cross section (A)=1.64/2=0.82 m2

Assuming thickness of roof slab=0.2 m



Height of tunnel (h) = crest level head regulater-thicnes slab-crest under sluice =1295-0.2-1293.5=1.3mTotal clear width=A/h =0.82/1.3=0.63mFor clear span o.5mNumbers of tunnel=0.63/0.5=1.26 say 1 tunnelAssume the thickness divide wall 0.2mOver width=0.4*2+0.2=1 mOnly 0ne bay of under sluice will be used for silt excluder

7.9 Design of Canal Out LetThe head regulate crest level is fixed 1295m&canal bed level is 12993.8mRight side canal capacity canal is 8.2m3/s

7.9.1 Out Let SizeQ=CLH3/2 where c=1.7 L =out let length H=water depth in canal=1.43m (from canal pc1)

L=

L= =2.82

There fore out let size 2.9m*1.5m (length & height)For left out let similar procedure followDischarge left side canal=1.78m3/s

L= =2.14 where depth canal=0.62 m

There fore outlet size=2.2m) 0.62m (length & height)

7.10 GateGate have extra dimension than out let. The gate are provided an angle iron from at wall side& at the bedSize gateOff take canal right side main canal



Opening 2.9m*1.5mSheet metal 3.0m*1.8m (length. height)Thickness sheet metal=4mmOff take canal left side main canalOpening 2.2m*0.62mSheet metal 2.3*1.1.8m (length. height)Thickness sheet metal=4mm

7.11 Design of Retaining Wall (Guide wall)To avoid out flanking of the river due to the control structure across the river a masonry guide wall is provided. Considerations; Analysis per meter span and moment heel The depth of the soil up to the top level of the wall The wall on the side of the soil inclined Soil homogenous Earth pressure at rest was considered

7.11.1 Upstream Retaining WallData available River bed level=1293.5m U/S HFL=1298.7 m Angle of repose Top width=0.5m (source soil mechanics Arora) Free board(FB)=0.5m(assumed) Anchored depth below river bed =0.6m (source soil mechanics Arora) Therefore, height of wing wall

H= (U/S HFL- river bed level) +FB+anchored depth H=+ (1298.5-1293.5) +0.5 +0.6= 5.61Take =5.6m mThe bottom width is=70%*H=5.6*0.7=3.9m

B=3.9m

Kp= =1/3



0.5

0.5 W3

W1

5mW3

PH PS 5.6m

W4

3.4 O

3.9



PU 5.6m

Fig 7.4 u/s wing wall

Table 7.2 Forces and moments acting on u/s retaining wall

No

Item Forces (KN)

Lever arm(m)

Moments at O(KN-m)

Vertical

horizontal

Overturning

restoring

1 W1=0.5*5*22.42 56.05 o.25 14.012 W2=0.5*3.4*5*22.42 190.4 1.63 310.983 W3=0.5*3.4*19.62*5 166.7 2.76 461.24 W4=3.4*0.6*22.4 44.88 1.95 87.515 Pa=0.5*19.62*5.62*1/

3-102.54 1.86 191.41

6 Ph=0.5*4.52*9.81 99.32 1.5 148.987 Pu=0.5*5.62*9.81 -

153.821.3 199.94

∑V= ∑H=3.22 ∑Mo=391.78Safety factors

Overturning stability,

Sliding stability,

Check for tension.

B/6=3.9/6=0.65m

Sincé e=0.12m no tensión.

As the result the structure is safe



7.11.2 Downstream retaining wallD/S HFL=1297.24Free board (FB) =0.5(assumed)Top width=0.5 m (source soil mechanics Arora)Therefore, H=+ (1297.24-1293.5) +0.5+0.6=4.63 say=4.6 m Provided bottom width, B=4.6mBottom width=0.7*4.6=3.2mB=3.2m

0.5m0.5m

W1

PS W3

PHW2

O W4

2.73.2m

4.6m

PU

Fig 7.5 d/s retaining

Table 7.3 Forces and moments acting on d/s retaining wall

No

Item Forces(KN)

Lever arm(m)

Moments at O(KN-m)

Vertical

Horizontal

Overturning

restoring

1 W1=0.5*4*22.4 44.8 O.25 11.2

2 W2=0.5*2.7*4*22.4 121.5 1.4 170.1

3 W3=0.5*2.7*4*19.62 105.95 1.8 190.71



4 W4=0,6*3.2*22.4 43.00 1.6 68.81

5 Ps==0.5*19.62*4.62*1/

3-69.19 1.53 106.09

6 Ph=o.5*3.528*9.81 60.08 1.33 81.66

7 Pu=0.5*4.62*9.81 -103.78

1.06 110.81

∑H=

Safety factors

Overturning stability,

Sliding stability,

Check for tension,

B/6=3.2/6=0.53Since e=0.0.5<0.53m, there is no tension.

CHAPTER EIGHT

8. ECONOMIC ANALYSISThe main of economical Analysis is to check weather a given project is economical or not. A given project said to be economically feasible implies that the total benefit of the project exceeds the total cost of the project (i.e. benefit cost ratio of the project should be greater than one)

Table 8.1rate of cost



NO Work Description

unit Quantity Unit cost Total cost

1 Access road

Km 2 4500 9000

2 Camping - 1 80,000 80,0003 Head Work -

8.2 Weir Apron And under Sluice portion

Site clearing M2 800 4 3200Foundation Excavation

M2 13014 20 27828

Masonry work M2 124.2 350 43470Concrete work

M2 126 4350 44100

Plastering M2 64 350 22400Gravel and filter

M2 75.6 55 4151

8.3 Head Regulator

NO Work Description

Unit Quantity Total cost

Concert piec(4=0.8m)

m - 700 700

Cote(0.4*0.4) pcs - 5000 5000

8.4 Retaining wall

NO Work Description


1 Masonry Work

M2 487.5 350 170625

2 Excavation M2 377.5 20 7552

8.5 Main Canal



NO Work Description


1 Excavation M2 133.328 20 26665602 Back fill M2 47,364 20 9472803 Drop 2-1-2-

5-7M2 129 350 45550

8.6 Secondary

NO Work Description


1 Excavation M2 52,188 20 10437602 Back fill M2 6990.4 20 139.8083 Drop 2-

1_2-11M2 89 350 31.150

8.7 Tertiary canal

NO Work Description


1 Territory M2 - - -

8.8 Culvert

NO Work Description


1 Concrete M2 1.2 300 3602 Masonry M2 0.9 350 3153 pipe PCS 0.2 1500 3000

8.9 Drainage Convey

NO Work Description


1 Excavation M2 - - -Estimation of Project benefit the Purpose of Irrigation Project is to increase the crop production in this case all the Agricultural out puts are sold for the assumed life time of the project which is 20 yrs.The following table shows the estimated benefit of the project



Table 8.10 Estimation 0f Project benefit

No Types of crop

Area(ha)

Yield qu/ha

Price(Birr/ha)

Labor per/ha

Labor cost/ha

T0tal cost/ha

Profit birr/ha

Total per/ha

1 Maize- i

21 36 14400 210 2100 2900 11,500 24,500

2 Hani been-ii

14 16 13120 150 1500 2250 10870 152182

3 Pepper 7 12 60000 240 2400 6200 53800 376600

4 Onion 7 152 76000 160 1600 3800 72200 505,400

5 Cotton 25 20 20000 250 2500 3700 16,300 407,500

6 Maize-i 40 36 14,400 210 2100 2900 11500 460,000

7 Hani been-i

30 16 13,120 150 1500 250 10,870 326100

8 Banana 5 100 100,000 180 1800 2500 97,500 480,500

Analysis of the EconomyAssuming useful time of the project to be 20 yrs interest rate; the annual worth or total cost will be

Assuming annual operation and maintatiance cost to be 10% of annul costO&M COST=0.1*621.998=621998

Using the Modified Benefit Cost Ratio Method B/C= (Bn-Mn)/CnWhere _Bn=net capital sowings to user

_Mn=user O&M cost_Cn=capital cost of replacing the present facility with future facility



= =4.6>1.0

Hence, the project economically feasible.

CHAPTER NINE



9. ENVIRONMENTAL IMPACT ASSESSMENT

9.1 GeneralDuring the construction of different projects, including irrigation system, those are intended to produce some developments, may cause irreversible environmental changes over a wide geographic area and thus have a potential for significant impacts. The area of influence of the project extends from the upper limits of the catchments to far down stream. Therefore the project such as Gelana irrigation structure system, are designed to enhance economic development and bring a better standard of life to people due consideration should be given to their adverse environmental and social effects. This can be done through environmental impact assessment (EIA) which is a management tool for officials and manager who take decision about important development project. The EIA not only predicts potential problems but also identifies measures to minimize the problems and out lines ways to improve the project suitability for its proposed environment.The aim of environmental impact assessments is;To understand the likely environmental consequences of redevelopments.To understand the amplification of proposed interventions.To identify measures by which the impacts can be mitigated.To present the results in such away that they can provide answers needed by stakeholders. Generally EIA can be described in short as an instrument used to identify, predict and assess the environmental consequences of a proposed major development project. Moreover EIA is used to plan appropriate measures to reduce adverse effects.Environmental impacts of any project can be classified in to two groups.1. Negative impacts2. Positive impacts

Negative impacts1. Impacts on Physical Environment2. Impacts on Biological Environment3. Impacts on Socio-Economic Environment



9.2 IMPACTS ON PHYSICAL ENVIRONMENT

9.2.1 Impacts on HydrologyThe irrigation structures have little impact on the total available water butsome detrimental effect on the distribution of water in terms of space and time. This has a significant effect on aquatic resource, recession agriculture wild life movements and other human activities downstream of the scheme. All these and other effects are brought about through the reduction and flood modification i.e. alteration to the liver regime.

9.2.2. Impact on Water QualityIrrigation projects usually yield high sediments during construction and low sediment rating during operation phases. Like inclination of trees and other vegetation may lead to increase in nitrate and phosphate imputes that would initiate eutrophication (depletion of oxygen).

9.2.3. Impact on Water loggingThe Water logging risk is common problem of the area due to the perched water table, because of the heavy soils.

9.2.4 Impact on Deforestation Trees and bosh are cleared from the project area, to provide safe irrigation system the clearances must be carried out over the whole area, including large trees if they interfere the irrigation lay out & area crop spraying. The types of bush’s & vegetable are dense woody bush with tall trees changes the whole environmental system & disturb the wild life habitat.

9.2.5. Reduction of Down Stream Below the dam site the flow regimes such as flood frequency, Velocity and volume reduce gradually. This charges the original river morphology and sediment transport of the down stream river basin.

9.2.6. Increase Risks of ErosionDuring the clearance of trees and vegetation, heavy weight of balloters capacity which consequences light surface flow &soil erosion. At the heavy rain fall the flood flow easily facilitate soil erosion since there are no enough trees to mitigate and reduce the flow. During the practice of the



land leveling the soil is disaggregated and is comes structurally weak. Earth work activities for roads, civil works, construction camps, etc. will remove and district the natural vegetation and top soil particularly on the steeper slopes increasing the potential for erosion. Roads are important contributor to soil erosion, primarily because they concentrate and distribute runoff as channel flow rather than a uniform over land or subsurface flow.

9.2.7. Impacts on Minerals and Construction Materials No any mineral occurs have been identified from the impact areas. The likely impact would be on construction materials mainly bed rocks for masonry, aggregate materials etc and quarries for various purposes.

9.2.8. Impact of Air QualityAir pollution is common during construction phase. Dust pollution caused by frequent movement of the construction vehicles and machineries coupled with wind effects suspended particles are the cause for many diseases. In addition to dust exhaust fumes or emissions released by diesel operating equipment cause air pollution.

9.3 Impacts on Biological Environment

9.3.1. Flora and FaunaPlant will certainly cause loss of natural vegetation and fauna available in those sites due to construction irrigation system.In most of the impact areas a fairly dense wood land or wooden grassland will be affected permanently. Animals moved to the adjacent areas could become more vulnerable to poaching by the local people or immigrant people during the construction period.

9.4. Impacts on Socio-Economic Environment

9.4.1. Loss of Land and Other Fixed PropertiesSince the method is surface or over head irrigation the great area is lost by aligning canal &furrows. The main impact for the surrounding local community will be losses of grazing land, bush land and wood land areas that comprise bushes and grasses which used to build houses. More over, the communication net work and social infrastructure will be affecting.



9.4.2. Increased Risk DiseaseDuring construction period there will be job opportunities attracting labor force from out side the area. This new influx will change the existing population. The main effects will be increased exposure of workers and their families to locally endemic diseases and sexually transmitted diseases. Open water ways and ponds inevitable involve risk of an invasion of material mosquitoes and other bore health hazards. In the project area saints which are the principal cause for a disease is called bilharzias, is mainly in habited in outlet works of dam and to main canal hade works.

9.5 Remedial Measures The proposed remedial measures and the impacts are shown below in the following table.

Table 9.1 Negative Environmental Impacts and Remedial Measures.

Impact Remedial Measures

1 Soil erosion - For any road construction side drains

longitudes drains, culverts and appropriate angle

of wet and fill should be incorporated to combat

soil erosion.

- Erodible surface should be cut only during

dry weather and replanted a soon as possible.

2

Water quality - Design ways and means to minimize erosion

and sediments, chemical pollution from

construction activities, pollution from human and

domestic waste from the camps and offices from

entering in to the river canals.

- Conducting periodic water quality

monitoring and dry out the canals to kill snails and

mosquitoes.



3 Air quality - Dust collectors or water spray systems is

require to prevent high dust emissions from batch

plant operations.

- Diesel engines of construction equipment

should be subjected to regular checking and

cleaning of the inspectors to minimize emissions.

4 deforestation - Remove vegetation as possible during the

development.

5 Loss of fixed

properties and land

- Provision of financial compensation for

hours and land loss to made way for the project.

- Allocation of financial compensation on the

basses of lost income from the land and the time

and labor necessary to bring new land into use.

6 Water logging - Buried pipe drains installed at low depth to

reduce the water table depth.

7 Health and sanitary

issues

- Employment of preventive and curative

measures to reduce transmission of

communicable diseased between the work force

and the local population.

- Health education campaign about sexually

transmitted diseases and their preventive

measures.

- Snail screens are incorporated in the design

of outlet works to avoid bilharzias.

- The design canals should flow relatively high



speed

9.6 POTENTIAL POSITIVE IMPACTSEffects on human beings & manmade features. Effects of the development on the surrounding area & landscape. Effects of the development on buildings, the arch textural & historic heritage, & archaeological features. Increased production when irrigation projects are implemented people can produce crops with good yield in season other than rainy season & erratic rainfall distributions i.e. crop production in dry season. More rounds of crops with availability of irrigation two or three round of crops can be manipulated on the same soil with proper rotation & fertilizer.Rise in social status with increased food production more money with be available with farmers & this raises their standard of living. Rise in social standards with increased food production &assured supplies of food & water more money is available with farmers & this raises their living standards. Since the project has a reservoir at dam site in addition to water collection if helps as a food control.



CHAPTER TEN

10. CONCLUSION AND RECOMENDATION

Based on the study and the result obtained the designed the following conclusions and recommendations are made.

10.1 ConclusionContribution of ground water level is not taken in to account in CWR Calculation.The soil topography of the area is quite good for irrigationTo estimate of design flood there is no fittest data.Determination of design flood taken from Gelana IDF depth storm, followed by USSCS &finally by triangular hydrographThe project area is alluvial loam soil in nature, good drainage facilities for the lands are made.Area allocation of each type of crop is based on dependability of crop on different parameters like marketability, popularity and climatic condition of command area.Penman - Monteith method is used to calculate crop water demand of the crops, which is accomplished by computer software programDetermination of effective rainfall using dependable rainfallIn n the project area there is no gauging station, therefore the six nearest metrological stations are available, but Arba Minch climatic

Characteristics taken determination ETOSurface irrigation design system is design by furdev compute softwareDesign of drainage canal done by maximum depth storm consider as mean annual rainfall due to lack fittest data

10.2 RecommendationsThe project cannot be handled the farmers only; it should be supported by the government agency.



To prevent canal from being silt up cleaning irrigation canal timely is importantThe data collected for student project work, some data is missing the concerned body of the university should be check the basic data input before deliver to student Education and training should be given to the farmers for adopting practice of conservative use of water on scientific manner.Formation of water users association can enhance peaceful usage of irrigation water and resolution of conflicts.Finally proper management, maintenance and use of the project should be given due consideration for the scheme to operate efficiently through out the design period practices.

REFERANCE1. Arora, K.R, Irrigation, water power &water resource engineering

stander published distribution, NoAia sake Delhi (2000)2. FAO, Guide line for predication of crop water requirement,

irrigation &drainage paper 24,FAO,ROME 3. Hydrology for engineering RAY,K LINSLE 19824. K.C, PATRA, Hydrology &water resource engineering, NORSA,

published5. Garg, SK, Irrigation & hydraulics structure 12th edition, New

Delhi 19956. Baba R.Design of diversion weir, small scale irrigation in hot

climate,weily & soon 19957. DR Punumia irrigation water power &water resource

engineering8. Michael A.M irrigation theory & practice,viks publishing limited

Delhi 19839. Environmental impact assessment (2000) B.Perty10. Irrigation structure& surface irrigation hand out

11.



ANNEXES-A



SEASON TWO4/29/2009 CropWat 4 Windows Ver 4.3******************************************************************************

Climate and ETo (grass) Data

******************************************************************************Data Source: C:\CROPWATW\CLIMATE\LG.PEM------------------------------------------------------------------------------Country : ETHIOPIA Station : GelanaAltitude: 1300 meter(s) above M.S.L.Latitude: 6.08 Deg. (North) Longitude: 37.58 Deg. (East)------------------------------------------------------------------------------Month MaxTemp MiniTemp Humidity Wind Spd. SunShine Solar Rad. ETo (deg.C) (deg.C) (%) (Km/d) (Hours) (MJ/m2/d) (mm/d)------------------------------------------------------------------------------January 31.4 14.3 51.8 95.0 9.1 21.5 4.51February 32.6 15.2 47.9 103.7 8.8 22.2 4.96March 32.6 16.2 52.5 121.0 8.1 22.0 5.19April 30.6 16.5 63.5 129.6 7.3 20.7 4.77May 28.7 16.1 69.0 155.5 7.8 20.7 4.58June 28.0 16.2 64.2 164.2 6.4 18.2 4.30July 27.5 15.8 63.3 155.5 4.8 16.0 3.97August 28.4 16.3 59.9 155.5 5.4 17.4 4.35September 29.6 16.1 60.1 138.2 6.9 20.0 4.67October 29.6 15.7 65.8 103.7 7.6 20.6 4.38November 30.1 14.0 60.2 103.7 9.1 21.7 4.48December 30.8 13.9 53.7 95.0 9.1 21.1 4.34------------------------------------------------------------------------------Average 30.0 15.5 59.3 126.7 7.5 20.2 4.54------------------------------------------------------------------------------



Pen-Mon equation was used in ETo calculations with the following values for Angstrom's Coefficients: a = 0.25 b = 0. ******************************************************************************C:\CROPWATW\REPORTS\ALL.TXT

4/29/2009 CropWat 4 Windows Ver 4.3****************************************************************************** ETo and Rainfall Data

******************************************************************************Data Source: C:\CROPWATW\CLIMATE\RC.CRM------------------------------------------------------------------------------ Month ETo Total Rainfall Effective Rain (mm/d) (mm/month) (mm/month)------------------------------------------------------------------------------ January 4.51 23.8 4.3 February 4.96 31.3 8.8 March 5.19 74.2 35.4 April 4.77 182.3 121.8 May 4.58 158.5 102.8 June 4.30 58.5 25.1 July 3.97 42.2 15.3 August 4.35 39.1 13.5 September 4.67 71.0 32.8 October 4.38 130.8 80.6 November 4.48 72.9 34.3 December 4.34 24.5 4.7------------------------------------------------------------------------------ Total (mm/Year) 1656.40 909.1 479.4



------------------------------------------------------------------------------

N.B. Effective rainfall calculated using the following formulas: Effective R. = 0.6 * Total R. - 10 ... (Total R. < 70 mm/month), Effective R. = 0.8 * Total R. - 24 ... (Total R. > 70 mm/month).******************************************************************

\

SAESON TWO

4/29/2009 CropWat 4 Windows Ver 4.3******************************************************************************

Crop Water Requirements Report

******************************************************************************

- Crop # : [All crops]- Block # : [All blocks]- Calculation time step = 10 Day(s)- Irrigation Efficiency = 70%

------------------------------------------------------------------------------Date ETo Planted Crop CWR Total Effect. Irr. FWS Area Kc (ETm) Rain Rain Req.



(mm/per) (%) (mm/per) (l/s/ha)------------------------------------------------------------------------------1/1 46.36 30.00 0.25 11.36 3.35 0.00 11.36 0.1911/1 47.31 5.00 0.06 2.79 0.77 0.00 2.79 0.0521/1 48.11 5.00 0.06 2.79 0.96 0.00 2.79 0.0531/1 48.72 5.00 0.06 2.78 1.15 0.00 2.78 0.0510/2 49.14 5.00 0.06 2.76 1.31 0.00 2.76 0.0520/2 49.35 12.00 0.09 4.29 3.55 0.19 4.09 0.072/3 49.37 75.00 0.37 18.27 23.34 3.17 15.10 0.2512/3 49.21 75.00 0.37 18.30 24.59 9.85 8.44 0.1422/3 48.88 75.0 0.49 23.96 25.43 18.31 5.64 0.091/4 48.42 75.00 0.67 32.63 25.91 25.09 7.55 0.1211/4 47.85 75.00 0.79 37.70 26.06 26.06 11.64 0.1921/4 47.20 75.00 0.81 38.47 25.92 25.92 12.55 0.211/5 46.51 75.00 0.81 37.90 25.54 25.54 12.36 0.2011/5 45.81 71.00 0.76 34.93 23.66 22.91 12.02 0.2021/5 45.12 35.00 0.38 17.35 11.33 8.46 8.89 0.1531/5 44.47 32.00 0.31 13.84 10.04 5.09 8.75 0.1410/6 43.88 5.00 0.05 2.19 1.51 0.44 1.76 0.0320/6 43.38 5.00 0.05 2.18 1.46 0.25 1.93 0.0330/6 42.97 30.00 0.16 7.04 8.42 0.84 6.20 0.1010/7 42.68 30.00 0.17 7.04 8.12 0.00 7.04 0.1220/7 42.49 30.00 0.17 7.06 7.86 0.00 7.06 0.1230/7 42.42 30.00 0.19 7.98 7.64 0.00 7.98 0.139/8 42.46 30.00 0.23 9.63 7.46 0.00 9.63 0.1619/8 42.60 30.00 0.27 11.31 7.31 0.38 10.93 0.1829/8 42.83 30.00 0.30 13.02 7.19 1.44 11.58 0.198/9 43.13 30.00 0.34 14.78 7.09 2.82 11.96 0.2018/9 43.49 30.00 0.36 15.66 7.01 4.82 10.84 0.1828/9 43.87 30.00 0.36 15.79 6.92 6.55 9.24 0.158/10 44.25 30.00 0.36 15.93 6.82 6.82 9.11 0.1518/10 44.62 30.00 0.36 16.06 6.69 6.69 9.38 0.1628/10 44.94 30.00 0.36 16.18 6.51 6.23 9.95 0.167/11 45.19 30.00 0.36 16.27 6.28 4.26 12.01 0.2017/11 45.36 30.00 0.35 15.76 5.99 1.97 13.79 0.2327/11 45.43 30.00 0.32 14.76 5.62 0.53 14.22 0.247/12 45.40 30.00 0.30 13.71 5.18 0.00 13.71 0.2317/12 45.26 30.00 0.28 12.64 4.67 0.00 12.64 0.2127/12 22.55 30.00 0.26 5.91 2.12 0.00 5.91 0.20------------------------------------------------------------------------------Total 1661.07 541.03 360.77 214.63 326.40 [0.15]------------------------------------------------------------------------------



* ETo data is distributed using polynomial curve fitting.* Rainfall data is distributed using polynomial curve fitting.******************************************************************************C:\CROPWATW\REPORTS\ALL.TXT


Irrigation Scheduling Report

******************************************************************************

* Crop Data:------------- Crop # 1 : COTTON- Block # : 1 - Planting date: 30/6

* Soil Data:------------- Soil description : Medium- Initial soil moisture depletion: 40%

* Irrigation Scheduling Criteria:---------------------------------- Application Timing: Irrigate each 14days.- Applications Depths: Refill to 100% of readily available soil moisture.- Start of Scheduling: 30/6

------------------------------------------------------------------------------Date TAM RAM Total Efct. ETc ETc/ETm SMD Interv . Net Lost User Rain Rain Irr. Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------30/6 140.0 91.0 14.2 14.2 1.9 100.0% 43.8 0 43.8 0.05/7 146.1 95.0 13.9 7.7 1.9 100.0% 1.910/7 152.3 99.0 13.7 9.6 1.9 100.0% 1.914/7 157.2 102.1 0.0 0.0 1.9 100.0% 9.6 14 9.6 0.015/7 158.4 102.9 13.4 0.0 1.9 100.0% 1.920/7 164.5 106.9 13.2 9.6 1.9 100.0% 1.9



25/7 170.6 110.9 13.0 9.6 1.9 100.0% 1.928/7 174.3 113.3 0.0 0.0 1.9 100.0% 7.6 14 7.6 0.030/7 176.8 114.9 12.8 1.9 2.0 100.0% 2.04/8 182.9 118.9 12.7 10.5 2.3 100.0% 2.39/8 189.0 122.8 12.5 12.1 2.6 100.0% 2.611/8 191.5 124.4 0.0 0.0 2.7 100.0% 8.0 14 8.0 0.014/8 195.1 126.8 12.4 5.7 2.9 100.0% 2.919/8 201.3 130.8 12.2 12.2 3.3 100.0% 6.324/8 207.4 134.8 12.1 12.1 3.6 100.0% 11.425/8 208.6 135.6 0.0 0.0 3.6 100.0% 15.1 14 15.1 0.029/8 213.5 138.8 12.0 11.3 3.9 100.0% 3.93/9 219.6 142.8 11.9 11.9 4.2 100.0% 12.58/9 225.8 146.7 11.9 11.9 4.6 100.0% 22.9 14 22.9 0.013/9 231.9 150.7 11.8 11.8 4.9 100.0% 12.118/9 238.0 154.7 11.7 11.7 5.2 100.0% 26.022/9 238.0 154.7 0.0 0.0 5.2 100.0% 46.8 14 46.8 0.023/9 238.0 154.7 11.6 0.0 5.2 100.0% 5.228/9 238.0 154.7 11.6 11.6 5.2 100.0% 19.83/10 238.0 154.7 11.5 11.5 5.3 100.0% 34.66/10 238.0 154.7 0.0 0.0 5.3 100.0% 50.4 14 50.4 0.08/10 238.0 154.7 11.4 5.3 5.3 100.0% 5.313/10 238.0 154.7 11.3 11.3 5.3 100.0% 20.518/10 238.0 154.7 11.2 11.2 5.3 100.0% 35.920/10 238.0 154.7 0.0 0.0 5.3 100.0% 46.6 14 46.6 0.023/10 238.0 154.7 11.1 10.7 5.4 100.0% 5.428/10 238.0 154.7 10.9 10.9 5.4 100.0% 21.32/11 238.0 154.7 10.8 10.8 5.4 100.0% 37.43/11 238.0 154.7 0.0 0.0 5.4 100.0% 42.8 14 42.8 0.07/11 238.0 154.7 10.6 10.6 5.4 100.0% 11.012/11 238.0 154.7 10.4 10.4 5.4 100.0% 27.817/11 238.0 154.7 10.1 10.1 5.4 100.0% 44.8 14 44.8 0.022/11 238.0 154.7 9.8 9.8 5.2 100.0% 16.527/11 238.0 154.7 9.5 9.5 5.0 100.0% 32.41/12 238.0 154.7 0.0 0.0 4.8 100.0% 52.0 14 52.0 0.02/12 238.0 154.7 9.2 0.0 4.8 100.0% 4.87/12 238.0 154.7 8.8 8.8 4.6 100.0% 19.312/12 238.0 154.7 8.4 8.4 4.4 100.0% 33.215/12 238.0 154.7 0.0 0.0 4.2 100.0% 46.0 14 46.0 0.017/12 238.0 154.7 8.0 4.2 4.2 100.0% 4.222/12 238.0 154.7 7.6 7.6 3.9 100.0% 16.827/12 238.0 154.7 7.1 7.1 3.7 100.0% 28.829/12 238.0 154.7 0.0 0.0 3.6 100.0% 36.2 14 36.2 0.0



1/1 238.0 154.7 5.1 5.1 3.6 100.0% 5.76/1 238.0 154.7 6.1 6.1 3.4 100.0% 17.0------------------------------------------------------------------------------Total 427.5 344.8 791.8 100.0% 472.6 0.0 0.0------------------------------------------------------------------------------

* Yield Reduction:------------------- Estimated yield reduction in growth stage # 1 = 0.0%- Estimated yield reduction in growth stage # 2 = 0.0%- Estimated yield reduction in growth stage # 3 = 0.0%- Estimated yield reduction in growth stage # 4 = 0.0% --------- Estimated total yield reduction = 0.0%

* These estimates may be used as guidelines and not as actual figures.------------------------------------------------------------------------------

* Legend:--------- TAM = Total Available Moisture = (FC% - WP%)* Root Depth [mm]. RAM = Readily Available Moisture = TAM * P [mm]. SMD = Soil Moisture Deficit [mm].

* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.******************************************************************************C:\CROPWATW\REPORTS\SCCC.TXT



******************************************************************************



* Crop Data:------------- Crop # 2 : MAIZE -1- Block # : 1 - Planting date: 1/3



------------------------------------------------------------------------------Date TAM RAM Total Efct. ETc ETc/ETm SMD Interv. Net Lost User Rain Rain Irr Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------1/3 140.0 84.0 0.0 0.0 2.5 100.0% 58.5 0 58.5 0.02/3 142.5 85.5 15.3 0.0 2.5 100.0% 2.57/3 154.7 92.8 15.8 12.3 2.5 100.0% 2.512/3 166.9 100.2 16.2 12.3 2.5 100.0% 2.515/3 174.3 104.6 0.0 0.0 2.5 100.0% 9.9 14 9.9 0.017/3 179.2 107.5 16.6 2.5 2.5 100.0% 2.522/3 191.5 114.9 16.8 12.4 2.7 100.0% 2.727/3 203.7 122. 17.1 14.9 3.4 100.0% 3.429/3 208.6 125.2 0.0 0.0 3.6 100.0% 10.5 14 10.5 0.01/4 215.9 129.6 17.2 7.7 4.0 100.0% 4.06/4 228.2 136.9 17.3 17.3 4.7 100.0% 8.811/4 238.0 142.8 17.4 17.4 5.1 100.0% 16.412/4 238.0 142.8 0.0 0.0 5.0 100.0% 21.4 14 21.4 0.016/4 238.0 142.8 17.4 15.1 5.0 100.0% 5.021/4 238.0 142.8 17.3 17.3 5.0 100.0% 12.726/4 238.0 142.8 17.2 17.2 5.0 100.0% 20.3 14 20.3 0.01/5 238.0 142.8 17.1 17.1 4.9 100.0% 7.56/5 238.0 142.8 16.9 16.9 4.9 100.0% 15.1



10/5 238.0 142.8 0.0 0.0 4.8 100.0% 34.5 14 34.5 0.011/5 238.0 142.8 16.8 0.0 4.8 100.0% 4.816/5 238.0 142.8 16.5 16.5 4.6 100.0% 11.8------------------------------------------------------------------------------Total 269.0 197.2 321.8 100.0% 155.1 0.0 0.0------------------------------------------------------------------------------




* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.******************************************************************************C:\CROPWATW\REPORTS\SMM.TXT



*****************************************************************************



* Crop Data:------------- Crop # 3 : BEAN-1- Block # : 1 - Planting date: 1/3



------------------------------------------------------------------------------Date TAM RAM Total Efct. ETc ETc/ETm SMD Interv. Net Lost User Rain Rain Irr. Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------1/3 70.0 31.5 0.0 0.0 2.0 100.0% 30.0 0 30.0 0.02/3 70.6 31.8 15.3 0.0 2.0 100.0% 2.07/3 73.4 33.0 15.8 9.9 2.0 100.0% 2.012/3 76.2 34.3 16.2 9.9 2.0 100.0% 2.015/3 77.8 35.0 0.0 0.0 2.0 100.0% 7.9 14 7.9 0.017/3 79.0 35.5 16.6 2.0 2.0 100.0% 2.022/3 81.8 36.8 16.8 10.0 2.2 100.0% 2.227/3 84.6 38.1 17.1 12.2 2.8 100.0% 2.829/3 85.7 38.6 0.0 0.0 3.0 100.0% 8.8 14 8.8 0.01/4 87.4 39.3 17.2 6.5 3.4 100.0% 3.46/4 90.2 40.6 17.3 17.3 4.0 100.0% 4.911/4 93.0 41.8 17.4 17.4 4.6 100.0% 9.212/4 93.5 42.1 0.0 0.0 4.7 100.0% 13.9 14 13.9 0.016/4 95.8 43.1 17.4 14.7 5.1 100.0% 5.1



21/4 98.0 44.1 17.3 17.3 5.5 100.0% 14.826/4 98.0 44.1 17.2 17.2 5.4 100.0% 24.8 14 24.8 0.01/5 98.0 44.1 17.1 17.1 5.4 100.0% 9.96/5 98.0 44.1 16.9 16.9 5.3 100.0% 19.810/5 98.0 44.1 0.0 0.0 5.3 100.0% 41.1 14 41.1 0.011/5 98.0 44.1 16.8 0.0 5.3 100.0% 5.316/5 98.0 44.1 16.5 16.5 5.3 100.0% 15.221/5 98.0 44.1 16.3 16.3 5.2 100.0% 25.124/5 98.0 44.1 0.0 0.0 5.2 100.0% 40.7 14 40.7 0.026/5 98.0 44.1 16.1 5.1 5.0 100.0% 5.031/5 98.0 44.1 15.8 15.8 4.6 100.0% 13.25/6 98.0 44.1 15.5 15.5 4.2 100.0% 19.67/6 98.0 44.1 0.0 0.0 4.1 100.0% 27.8 14 27.8 0.0------------------------------------------------------------------------------Total 332.7 237.7 408.5 100.0% 194.9 0.0 0.0------------------------------------------------------------------------------




* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.



******************************************************************************C:\CROPWATW\REPORTS\SBBB.TXT4/29/2009 CropWat 4 Windows Ver 4.3******************************************************************************


******************************************************************************

* Crop Data:------------- Crop # 4 : BANANA - Block # : 1 - Planting date: 1/3



------------------------------------------------------------------------------Date TAM RAM Total Efct. ETc ETc/ETm SMD Interv. Net Lost User Rain Rain Irr. Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------1/3 70.0 24.5 0.0 0.0 4.6 92.3% 32.6 0 32.6 0.02/3 70.3 24.6 15.3 0.0 4.9 100.0% 4.97/3 71.7 25.1 15.8 15.8 4.9 100.0% 13.812/3 73.1 25.6 16.2 16.2 4.9 98.7% 22.015/3 73.9 25.9 0.0 0.0 4.3 95.2% 36.0 14 36.0 0.017/3 74.5 26.1 16.6 4.9 4.9 100.0% 4.922/3 75.9 26.6 16.8 16.8 4.9 100.0% 12.627/3 77.3 27.0 17.1 17.1 4.9 99.9% 20.029/3 77.8 27.2 0.0 0.0 4.9 100.0% 29.8 14 29.8 0.01/4 78.7 27.5 17.2 9.7 4.9 100.0% 4.9



6/4 80.1 28.0 17.3 17.3 4.8 100.0% 11.811/4 81.5 28.5 17.4 17.4 4.8 100.0% 18.512/4 81.8 28.6 0.0 0.0 4.8 100.0% 23.3 14 23.3 0.016/4 82.9 29.0 17.4 14.4 4.8 100.0% 4.821/4 84.3 29.5 17.3 17.3 4.8 100.0% 11.326/4 85.7 30.0 17.2 17.2 4.7 100.0% 17.7 14 17.7 0.01/5 87.1 30.5 17.1 17.1 4.7 100.0% 6.46/5 88.5 31.0 16.9 16.9 4.6 100.0% 12.710/5 89.6 31.4 0.0 0.0 4.6 100.0% 31.3 14 31.3 0.011/5 89.9 31.5 16.8 0.0 4.6 100.0% 4.616/5 91.3 31.9 16.5 16.5 4.6 100.0% 11.021/5 92.7 32.4 16.3 16.3 4.5 100.0% 17.524/5 93.5 32.7 0.0 0.0 4.5 100.0% 31.1 14 31.1 0.026/5 94.1 32.9 16.1 4.5 4.5 100.0% 4.531/5 95.5 33.4 15.8 15.8 4.5 100.0% 11.25/6 96.9 33.9 15.5 15.5 4.4 100.0% 17.97/6 97.4 34.1 0.0 0.0 4.4 100.0% 26.8 14 26.8 0.010/6 98.3 34.4 15.2 8.8 4.4 100.0% 4.415/6 99.7 34.9 15.0 15.0 4.4 100.0% 11.420/6 101.1 35.4 14.7 14.7 4.4 100.0% 18.621/6 101.4 35.5 0.0 0.0 4.4 100.0% 22.9 14 22.9 0.025/6 102.5 35.9 14.4 13.0 4.4 100.0% 4.430/6 103.9 36.4 14.2 14.2 4.4 100.0% 12.15/7 105.3 36.8 13.9 13.9 4.4 100.0% 20.2 14 20.2 0.010/7 106.7 37.3 13.7 13.7 4.5 100.0% 8.515/7 108.1 37.8 13.4 13.4 4.5 100.0% 17.519/7 109.2 38.2 0.0 0.0 4.5 100.0% 35.5 14 35.5 0.020/7 109.5 38.3 13.2 0.0 4.5 100.0% 4.525/7 110.9 38.8 13.0 13.0 4.6 100.0% 14.330/7 112.3 39.3 12.8 12.8 4.6 100.0% 24.42/8 113.1 39.6 0.0 0.0 4.6 100.0% 38.3 14 38.3 0.04/8 113.7 39.8 12.7 4.7 4.7 100.0% 4.79/8 115.1 40.3 12.5 12.5 4.7 100.0% 15.614/8 116.5 40.8 12.4 12.4 4.8 100.0% 27.016/8 117.0 41.0 0.0 0.0 4.8 100.0% 36.5 14 36.5 0.019/8 117.9 41.3 12.2 9.6 4.8 100.0% 4.824/8 119.3 41.7 12.1 12.1 4.9 100.0% 17.029/8 120.7 42.2 12.0 12.0 4.9 100.0% 29.630/8 121.0 42.3 0.0 0.0 5.0 100.0% 34.5 14 34.5 0.03/9 122.1 42.7 11.9 11.9 5.0 100.0% 8.08/9 123.5 43.2 11.9 11.9 5.1 100.0% 21.413/9 124.9 43.7 11.8 11.8 5.1 100.0% 35.2 14 35.2 0.018/9 126.0 44.1 11.7 11.7 5.2 100.0% 14.2



23/9 126.0 44.1 11.6 11.6 5.2 100.0% 28.627/9 126.0 44.1 0.0 0.0 5.2 99.9% 49.5 14 49.5 0.028/9 126.0 44.1 11.6 0.0 5.2 100.0% 5.23/10 126.0 44.1 11.5 11.5 5.3 100.0% 20.08/10 126.0 44.1 11.4 11.4 5.3 100.0% 35.011/10 126.0 44.1 0.0 0.0 5.2 99.4% 50.8 14 50.8 0.013/10 126.0 44.1 11.3 5.3 5.3 100.0% 5.318/10 126.0 44.1 11.2 11.2 5.3 100.0% 20.723/10 126.0 44.1 11.1 11.1 5.4 100.0% 36.425/10 126.0 44.1 0.0 0.0 5.4 100.0% 47.1 14 47.1 0.028/10 126.0 44.1 10.9 10.7 5.4 100.0% 5.42/11 126.0 44.1 10.8 10.8 5.4 100.0% 21.57/11 126.0 44.1 10.6 10.6 5.4 100.0% 38.08/11 126.0 44.1 0.0 0.0 5.4 100.0% 43.4 14 43.4 0.012/11 126.0 44.1 10.4 10.4 5.4 100.0% 11.317/11 126.0 44.1 10.1 10.1 5.4 100.0% 28.422/11 126.0 44.1 9.8 9.8 5.4 99.9% 45.7 14 45.7 0.027/11 126.0 44.1 9.5 9.5 5.5 100.0% 17.72/12 126.0 44.1 9.2 9.2 5.5 100.0% 35.86/12 126.0 44.1 0.0 0.0 4.9 96.8% 56.9 14 56.9 0.07/12 126.0 44.1 8.8 0.0 5.5 100.0% 5.512/12 126.0 44.1 8.4 8.4 5.4 100.0% 24.317/12 126.0 44.1 8.0 8.0 5.4 100.0% 43.520/12 126.0 44.1 0.0 0.0 4.8 94.0% 58.8 14 58.8 0.022/12 126.0 44.1 7.6 5.4 5.4 100.0% 5.427/12 126.0 44.1 7.1 7.1 5.4 100.0% 25.51/1 126.0 44.1 5.1 5.1 5.5 100.0% 47.63/1 126.0 44.1 0.0 0.0 4.9 92.5% 57.8 14 57.8 0.06/1 126.0 44.1 6.1 6.1 5.6 100.0% 10.511/1 126.0 44.1 7.1 7.1 5.6 100.0% 31.216/1 126.0 44.1 8.2 8.2 5.5 98.8% 50.617/1 126.0 44.1 0.0 0.0 5.1 92.1% 55.7 14 55.7 0.021/1 126.0 44.1 9.2 9.2 5.6 100.0% 13.226/1 126.0 44.1 10.1 10.1 5.6 100.0% 31.031/1 126.0 44.1 11.0 11.0 5.6 99.8% 47.6 14 47.6 0.05/2 126.0 44.1 11.9 11.9 5.6 100.0% 16.010/2 126.0 44.1 12.7 12.7 5.5 100.0% 31.014/2 126.0 44.1 0.0 0.0 5.3 99.9% 52.9 14 52.9 0.015/2 126.0 44.1 13.5 0.0 5.5 100.0% 5.520/2 126.0 44.1 14.2 14.2 5.5 100.0% 18.925/2 126.0 44.1 14.8 14.8 5.5 100.0% 31.528/2 126.0 44.1 0.0 0.0 5.4 100.0% 47.8 14 47.8 0.0------------------------------------------------------------------------------



Total 932.2 792.6 1830.599.7%1065.9 0.0 0.0------------------------------------------------------------------------------


* These estimates may be used as guidelines and not as actual figures.------------------------------------------------------------------------------* Legend:--------- TAM = Total Available Moisture = (FC% - WP%)* Root Depth [mm]. RAM = Readily Available Moisture = TAM * P [mm]. SMD = Soil Moisture Deficit [mm].* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.******************************************************************************C:\CROPWATW\REPORTS\SBABA.TXT

SEASON ONE



******************************************************************************* Crop Data:------------- Crop # 1 : MAIZE- 2- Block # : 1



- Planting date: 1/9* Soil Data:------------- Soil description : Medium- Initial soil moisture depletion: 40%

* Irrigation Scheduling Criteria:---------------------------------- Application Timing: Irrigate each 14days.- Applications Depths: Refill to 100% of readily available soil moisture.

- Start of Scheduling: 1/9

------------------------------------------------------------------------------Date TAM RAM Total Efct. ETc ETc/ETm SMD Interv. Net Lost User Rain Rain Irr. Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------1/9 140.0 84.0 0.0 0.0 1.7 100.0% 57.7 0 57.7 0.0

3/9 143.6 86.1 11.9 1.7 1.7 100.0% 1.78/9 152.5 91.5 11.9 8.6 1.7 100.0% 1.713/9 161.4 96.8 11.8 8.6 1.7 100.0% 1.715/9 164.9 99.0 0.0 0.0 1.7 100.0% 5.2 14 5.2 0.018/9 170.3 102.2 11.7 3.5 1.7 100.0% 1.723/9 179.2 107.5 11.6 9.0 2.0 100.0% 2.028/9 188.1 112.9 11.6 11.2 2.5 100.0% 2.529/9 189.9 113.9 0.0 0.0 2.6 100.0% 5.2 14 5.2 0.03/10 197.0 118.2 11.5 8.6 3.1 100.0% 3.18/10 205.9 123.6 11.4 11.4 3.6 100.0% 8.513/10 214.8 128.9 11.3 11.3 4.1 100.0% 16.6 14 16.6 0.018/10 223.7 134.2 11.2 11.2 4.6 100.0% 10.923/10 232.7 139.6 11.1 11.1 5.2 100.0% 24.527/10 238.0 142.8 0.0 0.0 5.4 100.0% 45.8 14 45.8 0.028/10 238.0 142.8 10.9 0.0 5.4 100.0% 5.42/11 238.0 142.8 10.8 10.8 5.4 100.0% 21.57/11 238.0 142.8 10.6 10.6 5.4 100.0% 38.010/11 238.0 142.8 0.0 0.0 5.4 100.0% 54.2 14 54.2 0.012/11 238.0 142.8 10.4 5.4 5.4 100.0% 5.417/11 238.0 142.8 10.1 10.1 5.4 100.0% 22.522/11 238.0 142.8 9.8 9.8 5.4 100.0% 39.8



24/11 238.0 142.8 0.0 0.0 5.4 100.0% 50.7 14 50.7 0.027/11 238.0 142.8 9.5 9.5 5.5 100.0% 6.82/12 238.0 142.8 9.2 9.2 5.5 100.0% 24.97/12 238.0 142.8 8.8 8.8 5.3 100.0% 43.08/12 238.0 142.8 0.0 0.0 5.3 100.0% 48.3 14 48.3 0.012/12 238.0 142.8 8.4 8.4 5.1 100.0% 12.217/12 238.0 142.8 8.0 8.0 4.9 100.0% 28.922/12 238.0 142.8 7.6 7.6 4.6 100.0% 44.9 14 44.9 0.027/12 238.0 142.8 7.1 7.1 4.4 100.0% 15.31/1 238.0 142.8 5.1 5.1 4.2 100.0% 31.5------------------------------------------------------------------------------Total 253.3 206.6 519.1 100.0% 328.7 0.0 0.0------------------------------------------------------------------------------* Yield Reduction:------------------- Estimated yield reduction in growth stage # 1 = 0.0%- Estimated yield reduction in growth stage # 2 = 0.0%- Estimated yield reduction in growth stage # 3 = 0.0%- Estimated yield reduction in growth stage # 4 = 0.0% --------- Estimated total yield reduction = 0.0%

* These estimates may be used as guidelines and not as actual figures.------------------------------------------------------------------------------* Legend:--------- TAM = Total Available Moisture = (FC% - WP%)* Root Depth [mm]. RAM = Readily Available Moisture = TAM * P [mm]. SMD = Soil Moisture Deficit [mm].* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.******************************************************************************C:\CROPWATW\REPORTS\SMM.TXT





******************************************************************************* Crop Data:------------- Crop # 2 : BEAN-2- Block # : 1 - Planting date: 1/9* Soil Data:------------- Soil description : Medium- Initial soil moisture depletion: 40%

* Irrigation Scheduling Criteria:---------------------------------- Application Timing: Irrigate each 14days.- Applications Depths: Refill to 100% of readily available soil moisture.- Start of Scheduling: 1/9------------------------------------------------------------------------------Date TAM RAM Total Efc ETc ETc/ETm SMD Interv. Net Lost User Rain Rain Irr. Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------1/9 70.0 31.5 0.0 0.0 2.1 100.0% 30.1 0 30.1 0.03/9 71.4 32.1 11.9 2.1 2.1 100.0% 2.18/9 74.9 33.7 11.9 10.7 2.1 100.0% 2.113/9 78.4 35.3 11.8 10.8 2.2 100.0% 2.215/9 79.8 35.9 0.0 0.0 2.2 100.0% 6.5 14 6.5 0.018/9 81.9 36.9 11.7 4.6 2.5 100.0% 2.523/9 85.4 38.4 11.6 11.6 2.9 100.0% 4.528/9 88.9 40.0 11.6 11.6 3.4 100.0% 9.129/9 89.6 40.3 0.0 0.0 3.5 100.0% 12.7 14 12.7 0.03/10 92.4 41.6 11.5 11.2 3.9 100.0% 3.98/10 95.9 43.2 11.4 11.4 4.4 100.0% 13.713/10 98.0 44.1 11.3 11.3 4.6 100.0% 25.5 14 25.5 0.018/10 98.0 44.1 11.2 11.2 4.7 100.0% 12.123/10 98.0 44.1 11.1 11.1 4.7 100.0% 24.427/10 98.0 44.1 0.0 0.0 4.7 100.0% 43.2 14 43.2 0.028/10 98.0 44.1 10.9 0.0 4.7 100.0% 4.72/11 98.0 44.1 10.8 10.8 4.7 100.0% 17.5



7/11 98.0 44.1 10.6 10.6 4.5 100.0% 30.210/11 98.0 44.1 0.0 0.0 4.3 100.0% 43.4 14 43.4 0.012/11 98.0 44.1 10.4 4.3 4.2 100.0% 4.2------------------------------------------------------------------------------Total 169.7 133.3 279.0 100.0% 161.3 0.0 0.0------------------------------------------------------------------------------* Yield Reduction:------------------- Estimated yield reduction in growth stage # 1 = 0.0%- Estimated yield reduction in growth stage # 2 = 0.0%- Estimated yield reduction in growth stage # 3 = 0.0%- Estimated yield reduction in growth stage # 4 = 0.0% --------- Estimated total yield reduction = 0.0%* These estimates may be used as guidelines and not as actual figures.------------------------------------------------------------------------------* Legend:--------- TAM = Total Available Moisture = (FC% - WP%)* Root Depth [mm]. RAM = Readily Available Moisture = TAM * P [mm]. SMD = Soil Moisture Deficit [mm].* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.******************************************************************************C:\CROPWATW\REPORTS\SBB.TXT





******************************************************************************* Crop Data:------------- Crop # 3 : PEPER- Block # : 1 - Planting date: 15/9


* Irrigation Scheduling Criteria:---------------------------------- Application Timing: Irrigate each 7days.- Applications Depths: Refill to 100% of readily available soil moisture.- Start of Scheduling: 15/9------------------------------------------------------------------------------Date TAM RAM Total Efct. ETc ETc/ETm SMD Interv. Net Lost User Rain Rain Irr. Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------15/9 70.0 17.5 0.0 0.0 1.2 80.0% 29.2 0 29.2 0.018/9 73.0 18.3 11.7 3.0 1.5 100.0% 1.522/9 77.0 19.3 0.0 0.0 1.5 100.0% 7.6 7 7.6 0.023/9 78.0 19.5 11.6 0.0 1.5 100.0% 1.528/9 83.0 20.8 11.6 7.6 1.5 100.0% 1.529/9 84.0 21.0 0.0 0.0 1.5 100.0% 3.1 7 3.1 0.03/10 88.0 22.0 11.5 4.6 1.5 100.0% 1.56/10 91.0 22.8 0.0 0.0 1.5 100.0% 6.2 7 6.2 0.08/10 93.0 23.3 11.4 1.5 1.5 100.0% 1.513/10 98.0 24.5 11.3 7.7 1.5 100.0% 1.5 7 1.5 0.018/10 103.0 25.7 11.2 6.7 1.9 100.0% 1.920/10 105.0 26.3 0.0 0.0 2.0 100.0% 5.8 7 5.8 0.023/10 108.0 27.0 11.1 4.3 2.3 100.0% 2.327/10 112.0 28.0 0.0 0.0 2.6 100.0% 12.1 7 12.1 0.028/10 113.0 28.3 10.9 0.0 2.7 100.0% 2.72/11 118.0 29.5 10.8 10.8 3.1 100.0% 6.43/11 119.0 29.8 0.0 0.0 3.1 100.0% 9.6 7 9.6 0.07/11 123.0 30.8 10.6 9.9 3.5 100.0% 3.5



10/11 126.0 31.5 0.0 0.0 3.7 100.0% 14.4 7 14.4 0.012/11 128.0 32.0 10.4 3.8 3.9 100.0% 3.917/11 133.0 33.3 10.1 10.1 4.3 100.0% 14.4 7 14.4 0.022/11 138.0 34.5 9.8 9.8 4.7 100.0% 12.824/11 140.0 35.0 0.0 0.0 4.8 100.0% 22.3 7 22.3 0.027/11 140.0 35.0 9.5 9.5 4.8 100.0% 4.81/12 140.0 35.0 0.0 0.0 4.8 100.0% 23.9 7 23.9 0.02/12 140.0 35.0 9.2 0.0 4.8 100.0% 4.87/12 140.0 35.0 8.8 8.8 4.8 100.0% 19.88/12 140.0 35.0 0.0 0.0 4.8 100.0% 24.6 7 24.6 0.012/12 140.0 35.0 8.4 8.4 4.8 100.0% 10.615/12 140.0 35.0 0.0 0.0 4.8 100.0% 24.9 7 24.9 0.017/12 140.0 35.0 8.0 4.8 4.8 100.0% 4.822/12 140.0 35.0 7.6 7.6 4.8 100.0% 21.0 7 21.0 0.027/12 140.0 35.0 7.1 7.1 4.7 100.0% 16.729/12 140.0 35.0 0.0 0.0 4.7 100.0% 26.1 7 26.1 0.01/1 140.0 35.0 5.1 5.1 4.8 100.0% 9.25/1 140.0 35.0 0.0 0.0 4.9 100.0% 28.6 7 28.6 0.06/1 140.0 35.0 6.1 0.0 4.9 100.0% 4.911/1 140.0 35.0 7.1 7.1 4.9 100.0% 22.312/1 140.0 35.0 0.0 0.0 4.9 100.0% 27.2 7 27.2 0.016/1 140.0 35.0 8.2 8.2 5.0 100.0% 11.719/1 140.0 35.0 0.0 0.0 5.0 100.0% 26.6 7 26.6 0.021/1 140.0 35.0 9.2 5.0 5.0 100.0% 5.026/1 140.0 35.0 10.1 10.1 5.1 100.0% 20.1 7 20.1 0.031/1 140.0 35.0 11.0 11.0 5.1 100.0% 14.32/2 140.0 35.0 0.0 0.0 5.1 100.0% 24.5 7 24.5 0.05/2 140.0 35.0 11.9 10.2 5.1 100.0% 5.19/2 140.0 35.0 0.0 0.0 5.1 100.0% 25.6 7 25.6 0.010/2 140.0 35.0 12.7 0.0 5.1 100.0% 5.115/2 140.0 35.0 13.5 13.5 5.2 100.0% 17.516/2 140.0 35.0 0.0 0.0 5.2 100.0% 22.6 7 22.6 0.020/2 140.0 35.0 14.2 14.2 5.2 100.0% 6.523/2 140.0 35.0 0.0 0.0 5.2 100.0% 22.1 7 22.1 0.025/2 140.0 35.0 14.8 5.2 5.2 100.0% 5.22/3 140.0 35.0 15.3 15.3 5.2 100.0% 15.8 7 15.8 0.07/3 140.0 35.0 15.8 15.8 5.2 100.0% 10.19/3 140.0 35.0 0.0 0.0 5.2 100.0% 20.5 7 20.5 0.012/3 140.0 35.0 16.2 10.4 5.2 100.0% 5.216/3 140.0 35.0 0.0 0.0 5.1 100.0% 25.7 7 25.7 0.017/3 140.0 35.0 16.6 0.0 5.1 100.0% 5.122/3 140.0 35.0 16.8 16.8 4.9 100.0% 13.123/3 140.0 35.0 0.0 0.0 4.9 100.0% 18.0 7 18.0 0.0



27/3 140.0 35.0 17.1 14.5 4.8 100.0% 4.830/3 140.0 35.0 0.0 0.0 4.7 100.0% 19.0 7 19.0 0.01/4 140.0 35.0 17.2 4.7 4.6 100.0% 4.66/4 140.0 35.0 17.3 17.3 4.5 100.0% 10.1 7 10.1 0.011/4 140.0 35.0 17.4 17.4 4.4 100.0% 4.7------------------------------------------------------------------------------Total 486.2 327.9 862.1 100.0% 553.2 0.0 0.0------------------------------------------------------------------------------* Yield Reduction:------------------- Estimated yield reduction in growth stage # 1 = 0.5%- Estimated yield reduction in growth stage # 2 = 0.0%- Estimated yield reduction in growth stage # 3 = 0.0%- Estimated yield reduction in growth stage # 4 = 0.0% --------- Estimated total yield reduction = 0.0%

* These estimates may be used as guidelines and not as actual figures.------------------------------------------------------------------------------* Legend:--------- TAM = Total Available Moisture = (FC% - WP%)* Root Depth [mm]. RAM = Readily Available Moisture = TAM * P [mm]. SMD = Soil Moisture Deficit [mm].* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.******************************************************************************C:\CROPWATW\REPORTS\SPP.TXT4/29/2009 CropWat 4 Windows Ver 4.3******************************************************************************


******************************************************************************* Crop Data:------------- Crop # 4 : ONION



- Block # : 1 - Planting date: 15/9


* Irrigation Scheduling Criteria:---------------------------------- Application Timing: Irrigate each 7days.- Applications Depths: Refill to 100% of readily available soil moisture.- Start of Scheduling: 15/9------------------------------------------------------------------------------Date TAM RAM Total Efct. ETc ETc/ETm SMD Interv. Net Lost User Rain Rain Irr. Irr. Adj. (mm) (mm) (mm) (mm) (mm) (%) (mm) (Days) (mm) (mm) (mm)------------------------------------------------------------------------------15/9 42.0 10.5 0.0 0.0 1.7 80.0% 18.5 0 18.5 0.018/9 43.5 10.9 11.7 4.3 2.2 100.0% 2.222/9 45.6 11.4 0.0 0.0 2.2 100.0% 10.8 7 10.8 0.023/9 46.1 11.5 11.6 0.0 2.2 100.0% 2.228/9 48.6 12.2 11.6 10.9 2.2 100.0% 2.229/9 49.1 12.3 0.0 0.0 2.2 100.0% 4.4 7 4.4 0.03/10 51.2 12.8 11.5 6.6 2.2 100.0% 2.26/10 52.7 13.2 0.0 0.0 2.3 100.0% 9.0 7 9.0 0.08/10 53.7 13.4 11.4 2.4 2.5 100.0% 2.513/10 56.3 14.1 11.3 11.3 2.8 100.0% 4.6 7 4.6 0.018/10 58.8 14.7 11.2 11.2 3.2 100.0% 4.120/10 59.8 15.0 0.0 0.0 3.3 100.0% 10.7 7 10.7 0.023/10 61.3 15.3 11.1 6.9 3.6 100.0% 3.627/10 63.4 15.8 0.0 0.0 3.9 100.0% 18.6 7 18.6 0.028/10 63.9 16.0 10.9 0.0 3.9 100.0% 3.92/11 66.4 16.6 10.8 10.8 4.3 100.0% 13.93/11 66.9 16.7 0.0 0.0 4.4 100.0% 18.3 7 18.3 0.07/11 69.0 17.2 10.6 10.6 4.7 100.0% 7.610/11 70.0 17.5 0.0 0.0 4.7 100.0% 21.9 7 21.9 0.012/11 70.0 17.5 10.4 4.7 4.7 100.0% 4.717/11 70.0 17.5 10.1 10.1 4.8 99.4% 18.3 7 18.3 0.022/11 70.0 17.5 9.8 9.8 4.8 100.0% 14.024/11 70.0 17.5 0.0 0.0 4.7 98.8% 23.4 7 23.4 0.0



27/11 70.0 17.5 9.5 9.5 4.8 100.0% 4.81/12 70.0 17.5 0.0 0.0 4.6 99.2% 23.7 7 23.7 0.02/12 70.0 17.5 9.2 0.0 4.8 100.0% 4.87/12 70.0 17.5 8.8 8.8 4.8 99.4% 19.78/12 70.0 17.5 0.0 0.0 4.6 95.9% 24.2 7 24.2 0.012/12 70.0 17.5 8.4 8.4 4.8 100.0% 10.615/12 70.0 17.5 0.0 0.0 4.5 98.3% 24.7 7 24.7 0.017/12 70.0 17.5 8.0 4.8 4.8 100.0% 4.822/12 70.0 17.5 7.6 7.6 4.8 99.4% 20.8 7 20.8 0.027/12 70.0 17.5 7.1 7.1 4.7 100.0% 16.729/12 70.0 17.5 0.0 0.0 4.4 96.3% 25.8 7 25.8 0.01/1 70.0 17.5 5.1 5.1 4.8 100.0% 9.25/1 70.0 17.5 0.0 0.0 4.3 96.4% 27.9 7 27.9 0.06/1 70.0 17.5 6.1 0.0 4.9 100.0% 4.911/1 70.0 17.5 7.1 7.1 4.9 99.2% 22.112/1 70.0 17.5 0.0 0.0 4.5 91.3% 26.6 7 26.6 0.016/1 70.0 17.5 8.2 8.2 5.0 100.0% 11.719/1 70.0 17.5 0.0 0.0 4.6 97.4% 26.3 7 26.3 0.021/1 70.0 17.5 9.2 5.0 5.0 100.0% 5.026/1 70.0 17.5 10.1 10.1 5.1 99.0% 19.8 7 19.8 0.031/1 70.0 17.5 11.0 11.0 5.1 100.0% 14.32/2 70.0 17.5 0.0 0.0 4.9 98.1% 24.4 7 24.4 0.05/2 70.0 17.5 11.9 10.2 5.1 100.0% 5.19/2 70.0 17.5 0.0 0.0 4.8 98.6% 25.4 7 25.4 0.010/2 70.0 17.5 12.7 0.0 5.1 100.0% 5.115/2 70.0 17.5 13.5 13.5 5.2 98.8% 17.116/2 70.0 17.5 0.0 0.0 5.2 100.0% 22.3 7 22.3 0.020/2 70.0 17.5 14.2 14.2 5.2 100.0% 6.523/2 70.0 17.5 0.0 0.0 5.2 100.0% 22.1 7 22.1 0.025/2 70.0 17.5 14.8 5.2 5.2 100.0% 5.22/3 70.0 17.5 15.3 15.3 5.1 98.8% 15.2 7 15.2 0.07/3 70.0 17.5 15.8 15.8 4.9 100.0% 9.09/3 70.0 17.5 0.0 0.0 4.8 100.0% 18.6 7 18.6 0.012/3 70.0 17.5 16.2 9.5 4.7 100.0% 4.716/3 70.0 17.5 0.0 0.0 4.5 99.5% 23.1 7 23.1 0.017/3 70.0 17.5 16.6 0.0 4.5 100.0% 4.522/3 70.0 17.5 16.8 16.8 4.4 99.8% 9.823/3 70.0 17.5 0.0 0.0 4.3 100.0% 14.2 7 14.2 0.027/3 70.0 17.5 17.1 12.8 4.2 100.0% 4.230/3 70.0 17.5 0.0 0.0 4.1 100.0% 16.5 7 16.5 0.01/4 70.0 17.5 17.2 4.0 4.0 100.0% 4.06/4 70.0 17.5 17.3 17.3 3.8 100.0% 6.2 7 6.2 0.011/4 70.0 17.5 17.4 14.9 3.6 100.0% 3.6



------------------------------------------------------------------------------Total 486.2 342.0 898.6 99.4 566.1 0.0 0.0------------------------------------------------------------------------------* Yield Reduction:------------------- Estimated yield reduction in growth stage # 1 = 0.1%- Estimated yield reduction in growth stage # 2 = 0.0%- Estimated yield reduction in growth stage # 3 = 0.6%- Estimated yield reduction in growth stage # 4 = 0.1% --------- Estimated total yield reduction = 0.1%

* These estimates may be used as guidelines and not as actual figures.------------------------------------------------------------------------------* Legend:--------- TAM = Total Available Moisture = (FC% - WP%)* Root Depth [mm]. RAM = Readily Available Moisture = TAM * P [mm]. SMD = Soil Moisture Deficit [mm].* Notes:-------- Monthly ETo is distributed using polynomial curve fitting. Monthly Rainfall is distributed using polynomial curve fitting. To generate rainfall events, each 5 days of distributed rainfall are accumulated as one storm. Only NET irrigation requirements are given here. No any kind of losses was taken into account in the calculations.******************************************************************************C:\CROPWATW\REPORTS\SOO.TXT


Crop Water Requirements Report

******************************************************************************- Crop # : [All crops]- Block # : [All blocks]- Calculation time step = 10 Day(s)- Irrigation Efficiency = 70%------------------------------------------------------------------------------Date ETo Planted Crop CWR Total Effect. Irr. FWS



Area Kc (ETm) Rain Rain Req. (mm/period) (%) ---------- (mm/period) ---------- (l/s/ha)------------------------------------------------------------------------------1/1 46.36 29.00 0.29 13.50 3.11 0.00 13.50 0.2211/1 47.31 20.00 0.21 9.94 3.06 0.00 9.94 0.1621/1 48.11 20.00 0.21 10.10 3.86 0.00 10.10 0.1731/1 48.72 20.00 0.21 10.23 4.59 0.00 10.23 0.1710/2 49.14 20.00 0.21 10.32 5.24 0.00 10.32 0.1720/2 49.35 20.00 0.21 10.34 5.78 0.29 10.05 0.172/3 49.37 20.00 0.20 10.09 6.22 0.85 9.24 0.1512/3 49.21 20.00 0.20 9.64 6.56 2.63 7.01 0.1222/3 48.88 20.00 0.18 9.01 6.78 4.88 4.12 0.071/4 48.42 20.00 0.17 8.36 6.91 6.69 1.67 0.0311/4 47.85 20.00 0.17 1.59 1.39 1.39 0.20 0.0221/4 47.20 0.00 0.00 0.00 0.00 0.00 0.00 0.001/5 46.51 0.00 0.00 0.00 0.00 0.00 0.00 0.0011/5 45.81 0.00 0.00 0.00 0.00 0.00 0.00 0.0021/5 45.12 0.00 0.00 0.00 0.00 0.00 0.00 0.0031/5 44.47 0.00 0.00 0.00 0.00 0.00 0.00 0.0010/6 43.88 0.00 0.00 0.00 0.00 0.00 0.00 0.0020/6 43.38 0.00 0.00 0.00 0.00 0.00 0.00 0.0030/6 42.97 0.00 0.00 0.00 0.00 0.00 0.00 0.0010/7 42.68 0.00 0.00 0.00 0.00 0.00 0.00 0.0020/7 42.49 0.00 0.00 0.00 0.00 0.00 0.00 0.0030/7 42.42 0.00 0.00 0.00 0.00 0.00 0.00 0.009/8 42.46 0.00 0.00 0.00 0.00 0.00 0.00 0.0019/8 42.60 0.00 0.00 0.00 0.00 0.00 0.00 0.00 29/8 42.83 50.00 0.22 6.60 8.37 1.80 4.81 0.118/9 43.13 56.00 0.25 10.65 13.23 5.39 5.25 0.0918/9 43.49 70.00 0.36 15.54 16.35 11.24 4.29 0.0728/9 43.87 70.00 0.47 20.56 16.14 15.29 5.27 0.098/10 44.25 70.00 0.58 25.77 15.91 15.91 9.87 0.1618/10 44.62 70.00 0.68 30.33 15.60 15.60 14.73 0.2428/10 44.94 70.00 0.73 32.86 15.20 14.54 18.32 0.307/11 45.19 66.00 0.70 31.73 13.84 9.49 22.24 0.3717/11 45.36 50.00 0.57 25.69 9.98 3.29 22.40 0.3727/11 45.43 50.00 0.57 25.86 9.37 0.89 24.97 0.417/12 45.40 50.00 0.55 24.86 8.63 0.00 24.86 0.4117/12 45.26 50.00 0.52 23.42 7.78 0.00 23.42 0.3927/12 22.55 50.00 0.49 11.16 3.54 0.00 11.16 0.37------------------------------------------------------------------------------Total 1661.07 388.16 207.43 110.17 277.98 [0.21]------------------------------------------------------------------------------



* ETo data is distributed using polynomial curve fitting.* Rainfall data is distributed using polynomial curve fitting.******************************************************************************C:\CROPWATW\REPORTS\AL.TXT

Surface irrigation design

HEARY BEANINPUT DATA

Intake family 0.6 a b c f g

Intake coefficients: 1.32 0.76 7 8.15 2.88E-04

-

Manning's coefficient n 0.04

Furrow spacing W 1 m

Furrow slope S 0.004 m/m

Net irrigation depth Fn 44 mm

Area to irrigate A 1240 ha

-

ASSUMPTIONS FOR DESIGN

Total application efficiency Ea 70 %

Design inflow time Ti 900 min

* Length of the furrow * L 270 m

-

PROCEDURE

*Check of design inflow time* dT (min) New L = 86.8 m

WARNING

Surface Runoff ok

Deep Percolation ok

-

RESULTS

Design inflow time Ti 33.8 hrs Advance time Tt 1663 min

Farm width B 45925.9 m Net opportunity time Tn 366 min

Inflow per area A (Main d'eau) Qu 14433.9 l/s Design inflow time Ti 2029 min

Total number of furrows n_f 45926Average opportunity time Tav 578 min

Required inflow per furrow q 0.31 l/s Average intake depth Fav 61 mm

Advance coefficient ß 3.92 Gross application depth Fg 63 mm

Adjusted furrow perimetre P 0.36 m Surface runoff RO 2 mm

Furrow advance ratio AR 185 % Deep percolation DP 17 mm



Infiltration efficiency Ei 72 %


=

PEPPERINPUT DATA



-


Furrow spacing W 0.8 m




-





-

PROCEDURE

*Check of design inflow time*dT

(min) New L = 70.0 m

WARNING

Surface Runoff ok

Deep Percolation ok

-

RESULTS


Farm width B 27555.6 m Net opportunity time Tn 148 min

Inflow per area A (Main d'eau) Qu 10241.5 l/s Design inflow time Ti 1017 min










=

ONIONINPUT DATA



-






-





-

PROCEDURE


WARNING

Surface Runoff ok

Deep Percolation ok

-

RESULTS


Farm width B 27555.6 m Net opportunity time Tn 86 minInflow per area A (Main d'eau) Qu 13374.9 l/s Design inflow time Ti 1020 min










MAIZEINPUT DATA



-






-





-

PROCEDURE


WARNING

Surface Runoff ok

Deep Percolation ok

-

RESULTS












COTTONINPUT DATA



-






-ASSUMPTIONS FOR DESIGN




-

PROCEDURE


WARNING

Surface Runoff ok

Deep Percolation ok

-

RESULTS












ANNEXES-B

Engineering hydrology subrimanya 1998


galene irrigation system project

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