4. spatial database creation and analysis
TRANSCRIPT
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4. SPATIAL DATABASE CREATION AND ANALYSIS
4.1 OVER VIEW
For creation of spatial digital database both spatial and aspatial data is
required. Spatial data consist of base drainage transport, land use/land
cover soil geomorphology and physiographic maps. The aspatial data
consist of socio-economic and collateral data. For developmental
planning, it is necessary to prepare thematic maps. Thematic maps are
very much useful for management of natural resources. These maps are
prepared using satellite imageries and toposheets data using visual
interpretation and digital interpretation techniques.
4.1.1 Acquisition and Processing of Topomaps and Satellite Data
Acquisition and processing of raw data for preparation of thematic maps
involves the following steps.
1. Acquisition of satellite image( IRS-P6 LISS-IV MX 5.8 X 5.8 mt
resolution) data of the year 2007 from National Remote Sensing
Centre (NRSC), Balanagar, Hyderabad and toposheets on 1:25,000
scale from (SOI) Survey of India, Hyderabad.
2. Georeferencing of Survey of India toposheets based on latitude and
longitude values given in the topomaps.
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3. Subsetting and mosaicing done for the georeferenced toposheets to
form a continuous terrain and preparation of digital mosaic depicting
the entire study area.
4. Georeferencing of satellite data by taking the toposheet as reference,
extracting the Ground Control Points (GCPs) from SOI toposheets and
placing to the satellite imagery to bring it to real world.
5. Digital image enhancement and application of correction models for
making the digital data free from errors and distortions both
radiometry and geometry of the satellite data.
6. Preparation of thematic maps using visual interpretation technique
and digital image interpretation technique.
4.1.2 Visual Image Interpretation
A spatial image carries detailed information of all the features over the
surface of the earth at data acquisition time. Examine of the images is
systematically done by the image interpreter. Number of complexity
levels occurs during the interpretation of the spatial images. The study of
spatial images and Arial photographs includes various characteristics
displayed on an image viz., tone, pattern, texture, shape ,size, and
association etc , these all characteristics helps in interpretation of
different features on Arial photographs and satellite imagery during the
classification of features. In this present study, for the fused pictoral
data classification, key is prepared for a preliminary image, which is
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used during image interpretation process. Image interpretation key is
used for the extraction and transferring of the thematic features from the
satellite imagery. The doubtful areas are listed during preliminary image
interpretation before ground confirmation. After field verification based
on the information collected, modifications and corrections of doubtful
areas are carried out.
4.1.3 Generation of Spatial Database
Based on physical characteristics in the study area, derivation methods
of maps, (IMSD Technical Guidelines, NRSA, 1995) their sources,
environmental sensitivity and suitability of the following maps are
prepared. The types of data relevant to digital database are classified
based on origin of acquisition and creation. To prepare the digital
baseline database, three various types of data are defined.
a) Topographic Data: Maps prepared from (SOI) Survey Of India
toposheets (1:25,000) scale.
b) Collateral Data: Detailed socio-economic data, cadastral maps with
survey points, developmental work detail and other miscellaneous
data.
c) Thematic Data: Maps prepared by using IRS-P6 LISS-IV-MX high
resolution satellite data on 1: 10,000 scale.
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Topographic data Collateral data Thematic data
Base map Detailed socio-economic data Land use/Land
cover map
Administrative boundaries Cadastral survey points Geomorphology
map
Transport map Developmental work details Soil map
Drainage map GPS Survey points
Watershed map Other miscellaneous data
Slop map
Physiography map
Table 4.1 shows the generation of spatial database
4.2 SPATIAL DATA GENERATED FROM TOPOSHEETS
The various spatial databases generated from survey of India (SOI)
toposheets relevant for this study are:
Base map.
Drainage network map.
Transport network map.
Watershed map.
Physiography map.
Mandal reference map with village boundaries.
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Fig 4.1 Showing the toposheet map of the study area (Source: Survey of India Toposheets)
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4.2.1 Base Map Generation
Map is a representation of various features present on the earth’s surface
drawn to scale. A topographical map is a representation of physical
features of a given area. A base map is a skeleton structure of an area. A
base map is composed of various different features like administrative
boundaries, settlements, road network, water bodies, railway tracks,
canal, and forest etc., which are extracted from the topsheet. The base
map therefore drawn is scanned and digitized using ARCGIS software to
get digital output.
A map, representing the outline structure of the study area, is
known as a base map. The base map preparation is done by using survey
of India (SOI) toposheets on 1:25,000 scale (66A01NE, 66A01SE and
66A05NW 66A05SW) and with help of the satellite imagery the baseline
information is been updated. The features in the base map consist of
mandal boundary, village boundary, taluk boundary, water bodies, major
canal, major settlements, major/minor roads and other towns.
The study area includes seven revenue villages of Karamchedu
mandal namely Audipuai, Daggubadu, Karamchedu, Kesavarapadu,
Kodavalivaripalem, Kunkalamarru, and Swarna. Nagarjun Sagar
Jawahar Canal and Kommamur Major Canal flows through the study
area. A part of Ramperu River also passes through the study area.
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Fig 4.2 Base map of the studyarea
Prepared by kavita, Centre for Environment, IST, (Source: Survey of India Toposheets)JNTUH
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Village Wise Base Maps of Karamchedu Mandal
Fig 4.3 Base map of Audipudi and daggubadu village Prepared by kavita, Centre for Environment, IST, JNTUH (Source: Survey ofIndia Toposheets)
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Fig 4.4 Base map of Karamcheduandkesaravapadu village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.5 Base map of Kodavarivalipalem andKunkalamarru village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.6 Base map of Swarna village Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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4.2.2 Drainage Network Map
All the rivers, streams and canals present in the toposheets delineated to
prepare a drainage network map. Survey of India toposheets (SOI) are
used to prepare drainage network map. And further it is scanned and
digitized using ARCGIS software to get digital database. All water bodies
present in the toposheet are divided into wet areas and dry areas. Wet
water spread areas are not always same, it changes in every season. After
preparing the drainage network map this map is updated using high
resolution satellite imagery to know the newly constructed tanks.
Nagarjun Sagar Jawahar Canal and Kommamur major canal is present
in the study area. A part of Ramperu River also passes through the study
area. The drainage network pattern is dendritic type.
4.2.3 Transport Network Map
In a developing country transport network map plays a vital role for
overall development. For social, economic and educational development,
roads and rail accessibility is very much essential of a region. In the
study area, four classes of transport network namely, the metalled roads,
cart track and pack track area extracted from the survey of India
topographical maps on 1:25,000 scale. The transport network map is
updated with help of latest satellite data to get the information about the
newly constructed roads. All roads are connecting to the major
settlements and hamelets in the study area.
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Fig 4.7 Drainage map of the studyarea
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.8 Drainage map of Audipudi and daggubadu village Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.9 Drainage map of Karamchedu and kesaravapaduvillage
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.10 Drainage map of Kodavarivalipalem andKunkalamarru village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.11 Drainage map of Swarnavillage
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.12 Transport map of the studyarea
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.13 Transport map of Audipudi and daggubadu village Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.14 Transport map of Karamchedu andkesaravapadu village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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Fig 4.15 Transport map of Kodavarivalipalem andKunkalamarru village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
72
Fig 4.16 Transport map of Swarna village Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
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4.2.4 Watershed Map
Watersheds are the optimal hydrologic units for planning and
implementation of various development programs. Watershed is defined
as a “Natural Hydrologic entity that covers a specific area expanse of land
surface, from which the rainfall runoff flows to a defined drain, channel,
stream or river at any particular point.” From this generalized definition
it emerges that the size of a watershed is governed by the size of the
stream or river in question or the point of interception of the water
course like a dam, barrage, etc. Obviously, no political or administrative
boundaries govern a watershed. The size of the watershed could be some
lakhs of hectares or if a small stream is chosen, the same could be of a
few hundred hectares. To avoid this ambiguity and to suggest a stage
where land development could be of viable size a hierarchical approach
was suggested by the Ministry of Agriculture (MOA), Govt. of India, in
1990. According to Central Water and Power Commission (CWPC), the
country was distinctly delineated into 6 Water Resources Regions (WRR).
Region 1 Rivers falling into Arabian Sea,
excluding Indus system.
Region 2 The Indus basin in India.
Region 3 Rivers falling into the Bay of
Bengal, other than the Ganga and
the Brahmaputra systems
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Region 4 The Ganga system.
Region 5 The Brahmaputra system.
Region 6 Rajasthan.
Table 4.2 Water resources regions
Number of Hydrologic Units at Different Stages of Delineation of our
Country and watershed codification:
Regions Hydrologic units Watershed codification
Water Resources Regions 6 5.0 la sq.km (+)
Basins 35 0.50 la sq.km (+)
Catchments 112+ 0.05 la sq.km (+)
Sub-catchments 500+ 0.005 la sq.km (+)
Watersheds 3237+ A few hectares of land
Table 4.3 watersheds codifications
An alfa-numerical system of codification has been suggested by the MOA
under this system:
Water resources regions are assigned
numbers
1,2,3,4,5 & 6
Basins A, B, C……..
Catchments 1, 2, 3……….
Sub-catchments A, B, C……..
Watersheds 1, 2, 3……….
Sub Watersheds a, b, c………
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Mini Watersheds 1, 2, 3………
Micro Watersheds a, b, c……..
Table 4.4 watershed alfa numerical codifications
Thus, watersheds will have the codes like 1A1A1a1a...4C4D1c1c...
Watershed map scale
For extraction and identification of various different levels of hirachy
following map scale are proposed:
Source : SOI Toposheet, Ariel photograph and satellite imagery
Region : 1:1 Million
Basin : 1:1 Million
Catchment : 1: 250,000
Sub-catchment : 1: 50,000
Watershed : 1: 50,000
Sub-watershed : 1:50,000
Mini Watershed : 1:25,000
To prepare a watershed map, Survey of India toposheet (SOI) on
1:25,000 scale is used. SOI toposheet provides information about the
exact location of drainage network, and further it is updated with
satellite data to know newly formed stream or newly constructed tanks
etc. Watershed coding is shown in the fig 4.17 of the study area
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Fig 4.17 watershed map of the study area Prepared by kavita, Centre for Environment, IST, JNTUH (Source: Survey of IndiaToposheets)
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4.2.5 Physiography Map
Physiography map is to apprehend distribution and disposition of the
barriers of winds. This map is prepared using contours extracted from
SOI toposheets. In the study area, only one category is demarcated in the
map that is plains.
In the study area entire area is covered with plains, which
indicates very gentle slope terrain.
4.2.6 Mandal Reference Map With Village Boundaries
Mandal reference map is generated from Survey of India toposheet (SOI)
on 1:25,000 scale. There are seven revenue villages in the Karamchedu
mandal namely Audipudi, Daggubadu, Karamchedu, Kesavarapadu,
Kodavalivaripalem, Kunkalamarru and Swarna
The mandal Reference map of study area is shown in fig. 4.19
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Fig 4.18 physiography map of the study area Prepared by kavita, Centre for Environment, IST, JNTUH(Source: Survey of India Toposheets)
79
Fig 4.19 Showing mandal reference map of the study area Prepared by kavita, Centre for Environment, IST, JNTUHSource: Survey of India Toposheets)
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4.3 SPATIAL DATA GENERATED FROM SATELLITE DATA AND
OTHER DATASETS
Satellite data gives exact information about the features on the surface of
the earth. The spatial information on the earth surface changes time to
time. Spatial information depends on the resolution of the sensor. There
are four types of resolution, i.e. spatial resolution, temporal resolution,
radiometric resolution and spectral resolution. Spatial resolution
depends on the sensor of the satellite the finer is the resolution the more
detailed information is obtained. In the study area RESOURCESAT IRS –
P6 LISS-IV MX (5.8x5.8 mt) high resolution satellite data is used to get
more detailed information.
Fig 4.20 Showing satellite image of the studyarea (Source: National Remote Sensing Centre- NRSC)
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4.3.1 Generation of thematic layers
Land use /Land cover map. Soil map. Geomorphology.
4.3.2 Land Use/Land Cover Map
Land use pattern changes time to time everyday. Information on the use
of land resources is indispensable for the proper management, planning
and use of those resources. Land resources are very limited on the earth
surface. To tackle the uncontrolled growth related problems, knowledge
about the land use and land cover changes is necessary. For updating
land use/land cover maps time to time, a systematic framework is
required.
Remote sensing is rapidly rising technology, which helps in
collection and mapping land use/land cover data above huge area. As
remote sensing data is obtained in digital format, it is more amenable for
digital image processing. Land use map helps in study of environmental
problems and processes and it gives the information about the existing
land use pattern and helps to improve maintain the current level. Thus,
land use map is prepared to give ideas to planner of land, use pattern
and changes occurring everyday on the earth’s surface.
4.3.2.1 Objective
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The main objectives of this new land use / land cover classification
system are:
To prepare a detailed framework and cover five levels of
classifications of land use/land cover as possible.
To prepare land use/land cover map with IRS –P6 LISS-IVMX (5.8
X 5.8 mt), high resolution satellite data and extract various land
use/land cover categories with the help of digital image processing.
To develop village level land use/land cover classification for micro-
level planning.
To prepare 1:10,000 large scale map.
4.3.3 Technical Steps of Digital Image Classification
Digital Image Processing (DIP) Techniques can be divided broadly into
4 groups. They are:
Image Rectification and Restoration.
Image Enhancement.
Image Interpretation.
Data Merging.
4.3.3.1 Image Rectification and Restoration
Before digital image processing, pre-processing is done for the raw
satellite data. Image rectification and restoration is done for raw satellite
data. Raw satellite obtained from the satellite sensor is either degraded
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or distorted. The raw satellite data is geometrically corrected to remove
the distortion of the image, and the image is radiomrtrically corrected to
remove the noise effect from the satellite data. The nature of the satellite
data depends on the sensor of the satellite.
4.3.3.2 Image Enhancement
The raw satellite images received from the satellite sensors are not
interpretable mainly due to unfavorable weather condition and requires
image enhancements. Image enhancement is the procedure carried out
to clear and enhance the basic quality of the image to be interpreted. It
includes spatial enhancement, radiometric enhancement and spectral
enhancements. This technique helps to interpret the maximum
information from the raw satellite image. These enhanced images can
further be displayed on the monitor and can be recorded in the form of
hard copy in both color and black and white.
4.3.3.3 Image Interpretation
There are two types of interpretations, visual interpretation and digital
interpretation. Visual Interpretation is based on principal image
identification. It is based on object recognition and characteristics of the
image. The image characteristics are tone, shape, pattern, size, shadow,
association and texture. Digital image interpretation deals with thematic
information extraction in digital classification. In digital interpretation,
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computer interpretation is subjective to two types of classification,
supervised and unsupervised.
(a) Supervised classification: The identity and location of pixels are known
that is priory knowledge of the training pixel is known by the interpreter
based on ground truth. Spectral characteristics of the training pixels are
used to train the classification pixels are assigned to a particular class, to
which it has highest likelihood being a member. Representative training
sites are selected for the process of signature extension. Statistics is
extracted for each training site. Selection of appropriate classification
algorithm classifying the image into required number of classes. Statistical
evolution is for the classification accuracy.
(b) Unsupervised classification: In unsupervised classification, the
interpreter does not have the knowledge of the classes or categories in this
classification. The role of interpreter is minimum. Classification based on
concept of natural clustering of the pixel. There are two methods, which
are most commonly used in unsupervised classification that is chain
method and isodata method.
4.3.3.4 Data merging
Data merging is the procedure carried out to merge two different
geographically referenced images of the same area in order to get high
resolution data.
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4.3.4 Methodology for land use/land cover mapping
For interpretation and analysis of land use/land cover mapping, baseline
data and ground data is required. Basic data includes satellite data from
NRSC, toposheets data from SOI, local knowledge, area map, reports and
literature about the study area. Ground data is important to get the
accurate information. Flowchart 4.1 showing the methodology adopted
for land use/land cover mapping.
Flowchart 4.1: Flowchart showing the Methodology adopted forLand Use/Land Cover mapping
Final land use/land cover mapwith symbols and color
Basic data Data source
IRS –P6-LISS-IV-MX Preparationof basemap
Interpretation and mapping ofland use /land cover categories
Ground verification of doubtful areas andmodification of thematic details
Area estimation of eachLand use/Land cover
classes
Development ofinterpretation key based
on imagecharacteristics.
Validation andfinal
interpretationkey
Secondary data
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Table: 4.5 Data Model for Land use/Land cover on 1:10,000 Scale
Level 1 Level 2 Level 3 Level 4 Level 5I Built-up 11 Urban/ Built-up
Land111 Residential
1111 High Density1112 Medium Density1113 Low Density
11111 Single Unit Highdensities
11112 Multiple dwellingLow rises
11113 Multiple dwellinghigh rises
112 Industrial1121 Light industrial1122 Heavy industrial1123 Power generation
113 Commercial
1131 Central Business centers1132 Commercial strips1133 Commercial establishmentsfor
goods and services1134 Isolated commercial office
buildings1135 Shopping centers1136 Resorts, Hotels &related
Facilities
114 Services
1141 Educational institutions1142 Health institutions1143 Correctional institutions1144 Government centers1145 Military installations1146 Other institutions
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115 Recreational
1151 Parks1152 Play grounds1153 Stadiums1154 Race course1155 Golf course1156 Swimming pools1157 Cultural centers andTheatres1158 Other recreational places
116.Transportation
Communication andUtilities
1161 Major road ways
1162 Railway facilities
1163 Bus stands1164 Airports1165 Power facilities1166 Telephone1167 Port facilities1168 Water & sewage treatment1169 Others
11611 NH11612 SH11613 District Roads11614 Other Roads
11621 Broad gauge11622 Meter gauge
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117 Open spacesor vacantland
1171 Undeveloped land withinurban area1172 Inactive land1173 Open areas
118 Others
12 Village / Rural
2.Agriculture 21 Crop land 211 Kharif212 Rabi213 Kharif +Rabi214 SummerCrop
22 Fallow221 CurrentFallow222 Permanent
Fallow23 Plantations
231 AgriculturalPlantations
2311 Tea2312 Coffee2313 Rubber
232 HorticulturalPlantations
2321 Coconut2322 Arecantnut2323 Citrus fruits2324 Orchards2325 Nurseries2326 Floury culture
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233 Agro-HorticulturalPlantations
2331 Seed forms2332 Others
24 Aquaculture/Pisciculture
3. Forest 31 Evergreen/ Semievergreen
32 Deciduous(Moist/Dry)
33 Forest Plantations
34 Scrub Forest
35 Forest Blank
36 Mangroves
37 Shifting cultivation
311 Dense/Closed312 Open/Degraded321 Dense/Closed322 Open331 Teak Forest332 BambinoForest333 Eucalyptus334 Casuarinas
361 Dense362 Open/
Degraded
4 Wastelands 41 Salt Affected Land
42 Gullied/ RavenousLand
43 Scrub land431 DenseScrubs432 Open Scrubs
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44 Sandy area
45 Mining/ Industrialwaste/ Ash
441 Coastal Sand442 ReverineSand
451 Mine Dumps452 IndustrialDumps453 Ash Ponds
5 Waterbodies
51 Rivers/ Stream
52 Canals
53 Reservoirs/ Tanks
54 Lakes/ Ponds55 Cooling pond/
Coolingreservoir
56 Bay
511 Perennial512 Dry(Ephimeral)513 River Island514 River bed
Cultivation
521 Lined Canal522 Unlined
531 Perennial532 Dry
5311 Multi purpose reservoirs5312 Balancing reservoirs
541 Perennial542 Dry
561 Back waters562 Estuary/Kayal563 Creek564 Lagoon
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6 Wetlands 61 Inland Natural
62 Inland Manmade
63 Coastal Natural
64 Coastal Manmade
7 Natural /Semi-NaturalGrass landand Grazingland
71 Alpine/Sub-Alpine
72 Temperate/ Sub-
Tropical
73 Tropical/Desertic
74 Man Made
Grasslands/ Fodder
Crop
8 Snowcovered
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4.3.5 Land Use/Land Cover Description of Study Area
The Land use/Land cover categories such as built-up land, agriculture,
water body, waste lands, canals, rivers, roads, and tanks have been
identified and mapped from the study area. Major part of the study area
is covered with double crop 50% and under built-up land 6%. The
agricultural area could be clearly delineated as three categories, single
crop, double crop and fallow land. Though, double crop has been
observed at various parts of the study area, single crop is observed only
at a few places of the study area. Approximately 4% of the area is covered
with land without scrub and rest of 40% of the area is covered with water
bodies.
Percentage wise distribution and area in sq.km of the study area.
Canal1%
wet tank1%
Double crop37%
harvested crop1%
Residential area2%
River with water1%
Road2%
Single crop54%
Pie Chart: 4.1 chart showing percentage distribution of Land use/ Land cover inthe study area
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Fig 4.21 Land use /land cover map of the study area Prepared by kavita, Centre for Environment, IST, JNTUH(Source: IRS P6 LISS-IV MX Satellite image from NRSC)
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Class Area (Km2)
BUND 0.34CANAL 1.316CURRENT FALLOW LAND 0.55DOUBLE CROP 56.97DRIED TANK 0.371FALLOW LAND 0.011HARVESTED CROP 1.295KOMMAMUR CANAL 0.599LAND WITHOUT SCRUB 0.292NAGARJUNASAGAR JAWAHAR CANAL 0.164POND 0.033RESIDENTIAL AREA 3.74RIVER WITH WATER 0.917RIVER WITHOUT WATER 0.527ROAD 2.53SINGLE CROP 83.93WET TANK 0.787
Table 4.6 Land Use/Land Cover Distribution in the Study Area
4.3.5.1 Crops Cultivated
Paddy, maize, bengal gram, black gram, chilli, cotton, tobacco and jute have
been identified in the study area. Lift irrigation facilities are available in the study
area.
Table 4.7 Area under principal crop cultivation
Crop Name Kharif Rabi Total
IrrigatedUnirrig-ated
Irrigated Unirrigated Irrigated
Unirrigated
Paddy 5993 0 7110 0 13103 0Maize 0 0 0 60 0 60Black gram 0 352 0 1439 0 1691Chillies 0 239 0 460 0 699Cotton 0 180 0 0 0 150Jute 0 20 0 0 0 20Tobacco 0 0 0 105 0 105Bengal gram 0 0 0 2271 0 2271
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Table 4.8 Village wise Land use / Land cover area in Km2
VillageName Bund Canal
CurrentFallowLand
DoubleCrop
DriedTank
FallowLand
Harv-stedCrop
Komm-amurCanal
LandWithoutScrub
NagarjunSagarJawaharCanal Pond
Reside-ntialArea
RiverWithWater
River
withoutWater Road
Sin-gleCrop
WetTank
Audipudi 0.172 5.008 0.002 0.00004 0.514 0.095 0.033 0.188 12.044 0.17
Daggubadu 2.225 0.172 0.11 0.00019 0.0976 0.577 0.072 0.198 0.193 12.453 0.102
Karamchedu 0.345 0.428 19.942 0.0077 0.186 0.194 0.0045 1.046 0.686 0.196 0.33 13.061 0.223
Kesavarapadu 0.21 0.025 0.023 0.193 0.0287 0.068 2.827 0.1
Kodavalivaripalem 0.035 0.055 9.707 0.094 1.295 0.076 0.023 0.043 0.254 0.06 0.024 0.21 9.445 0.085
Kunkalamaru 0.179 5.379 0.144 0.022 0.468 14.818 0.04
Swarna 0.496 14.451 0.068 0.191 0.074 0.005 0.691 0.044 1.545 19.218 0.063
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Village Wise Land Use/Land Cover Maps Of Karamchedu ,Mandal
Fig 4.22 Land use/Land cover map of Audipudiand
daggubadu village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: IRS P6 LISS-IV MX Satellite image from NRSC)
97
Fig 4.23 Land Use/Land cover map of Karamchedu andkesaravapadu village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: IRS P6 LISS-IV MX Satellite image from NRSC)
98
Fig 4.24 Land use/Land cover map of Kodavarivalipalem andKunkalamarru village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: IRS P6 LISS-IV MX Satellite image from NRSC)
99
Fig 4.25 Land use / land cover map ofSwarna village
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: IRS P6 LISS-IV MX Satellite image from NRSC)
100
4.4 SOIL MAP
4.4.1 Methodology
Soil map is prepared with the help of Survey of India toposheets on
1:25,000 scale and IRS P6 LISS-IV MX (5.8 x5.8 mt) satellite imagery
from NRSC. Topographic data is taken and it is superimposed on the
satellite data. Further image characteristics namely texture, tone,
pattern, shape and association are prepared in order to compare with the
soil distribution. Strip wise samples were haphazardly selected for
further field verification. Field visits are carried out to know the soil
profile characteristics and correlate the interpretation units with the
given study area. After the field verification and observations carried out
in the field, soil boundaries are drawn throughout the preliminary visual
interpretation and legends were prepared showing the soil series.
Afterward, the soil boundaries were shifted to the base map. The soil
map is shown in fig 4.26.
101
Fig 4.26 Soil map of the studyarea
Prepared by kavita, Centre for Environment, IST, JNTUHSource: National Bureau of Soil Survey (NBSS)Nagpur)
102
Soil Code Description Soil Taxonomy
238
Deep, well drained,
gravelly clay soils with
surface crusting and
low AWC; on gently
sloping plains,
moderately eroded and
associated with very
deep well drained
clayey soils.
Fine, mixed, Rhodic
Paleustalfs.
241
Deep, well drained, red
coastal clayey soils
with high awc, on very
gently sloping plains,
slightly eroded;
associated with very
deep, well drained, red
coastal clayey soils.
Fine, Mixed, Typic
Ustropepts,--Fine,
Mixed,Typic
Haplustalfs
246 Moderately deep,
moderately well
drained, black
cracking clay,
Fine, Montmorillonitic
(calcareous), Vertic
Usropepts)-- Fine,
Mixed, Typic
103
calcareous soils with
high awc, on very
gently sloping plains,
slightly eroded;
associated with deep,
well drained, black
clayey soils.
Ustropepts
Table 4.9 Distribution of soil type in the study area
4.5 GEOMORPHOLOGY
4.5.1 General
The Geomorphological map is prepared by demarcating the geomorphic
units and land forms. All available geomorphic units and forms are listed
after interpreting the study area. All the listed geomorphic units and
landform details are grouped/classified as per the origin like fluvial,
alluvial, structural, etc. The geological details like lithology/rock types
and structural details are also delineated using available
geological/geomorphological maps of the area. Then these geological
details are incorporated on geomorphological map for identifying the
groundwater potential associated with each geomorphology unit. For
instance pediment/Pedi plain without fractures/joints and lineaments
normally has moderate to poor groundwater prospect where as the same
geomorphic unit with a network of fractures/joints indicates good
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groundwater prospects. Similarly, a Pedi plain area of
crystalline/metamorphic rock is marked by poor to moderate
groundwater prospect wherein the same unit in sandstone or
limestone/sedimentary rock can have a good to moderate prospect. The
geomorphic units are delineated based on the image characteristics like
tone, texture, shape, color, associations, background, etc. The following
geomorphic units are delineated in study area.
Geomorphicunit/ land form
Description Influence on ground waterregime
Moderatelyweatheredpediplain.PPM
Gently undulating plain of large arealextent often dotted with inselbergsformed by the coalescence of severalpediments. Based on the depth ofweathering, weathered pediplains areclassified into 3 categories: (1) shallow(0-10m), (2) Moderate (10-20m), (3) Deep(>20m). Nearly half of the study area i.e.41.1% (2644.16 Km2) is occupied by thisclass. PPM is well distributed in theentire study area and is observed inareas along Musi river and in areassurrounding the tanks.
Pediplain occupied by semi-consolidatedsediments form good aquifers dependingon their composition. In hard rocks,they form very good recharge andstorage zones depending upon thethickness of weathering andaccumulated material and itscomposition. Faults/fractures zonespassing through pediplains act asconduits for movement and occurrenceof groundwater.
ShallowweatheredpediplainPPS
Gently undulating plain of large arealextent often dotted with inselbergsformed by coalescence of severalpedimets. Based on the depth ofweathering, weathered pediplains areclassified into 3 categories: (1) shallow(0-10m), (2) Moderate (10-20m), (3) Deep(>20m). This is the second major classobserved in the study area with a totalarea of 2212.18Km2 (34.42%). Itoccupies mostly the western andnortheastern parts of the study area.
Pediplain occupied by semi-consolidatedsediments form good aquifers dependingon their composition. In hard rocks,they form very good recharge andstorage zones depending upon thethickness of weathering andaccumulated material and itscomposition. Faults/fractures zonespassing through pediplains act asconduits for movement and occurrenceof groundwater.
Valley FillVF
Valleys of different shapes and sizesoccupied by valley fill material (partlydetrital and partly weathered material).They are classified into 3 categories – 1)Shallow (0-10 m), 2) Moderate (10-20m), 3) Deep (more than 20 m). Valley fillin the present study area occupy10.89Km2 in the southeastern part.
Form moderately productive shallowaquifers, subject to thickness of valleyfill material, its composition andrecharge conditions.
Table 4.10 Geomorphic units in the study area
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Fig 4.27 Geomorphology map of thestudy area
Prepared by kavita, Centre for Environment, IST, JNTUH(Source: IRS P6 LISS-IV MX Satellite image from NRSC)