the morphometric characterization of the … 05 35.pdf · analyzing the properties of the...

I.Boldea, C. Sigmirean, D.-M.Buda

THE CHALLENGES OF COMMUNICATION. Contexts and Strategies in the World of Globalism

266 Section: Social Sciences

THE MORPHOMETRIC CHARACTERIZATION OF THE HYDROGRAPHIC

NETWORK ON THE CALIMANI MOUNTAINS USING GIS TECHNIQUES

Lucian Moldovan

Teaching Assist., PhD Student, ”Dimitrie Cantemir” University of Tîrgu Mureș/

”Babeș-Bolyai” University of Cluj-Napoca

Abstract: The study indicates that the analysis of the morphometric parameters using Geographic

Information Systems (GIS) is a viable method in identifying the geomorphological characteristics and

analyzing the properties of the hydrographic basins in the mountainous area of the Calimani massif. For the morphometric component evaluation we used the global altimetric numerical model Shuttle Radar

Topography Mission (SRTM) with a resolution of 25 m. The GIS analysis methods of satellite data

provide us with a very efficient and time saving solution, and with an exact technique for the morphometric analysis of extensive areas. For the validation of the obtained results we used the

topographic maps 1: 25000 and the ortho-photo-maps offered by the National Agency of Cadastre and

Real Estate Advertising (ANCPI). The morphometric parameters of the hydrographic basins were determined by ArcGis computer based mapping programs (ESRI). Of these, the most important are: the

length of the basin, the width, the length and density of the hydrographic network, the surface of the

basin, etc. The obtained results can be used in the management of the studied area but also in the

subsequent studies.

Keywords: GIS, Hydrographic network, Morphometry, Geoprocessing, Watershed Delineation

Introduction

Delimitating river basins, generating hydrographic network and determining the morphometric

characteristics of rivers are key factors in hydrological studies. Until three decades ago, these

activities have traditionally been done topographically with topographic maps and aerial

photographs. Nowadays, with the emergence of new techniques and the development of

computer operations, these procedures are much easier to elaborate, being widely deployed using

geographic information systems.

Studied area

The studied area occupies the north-western part of the central group of the Eastern Carpathians,

being the largest volcanic massif in Romania. To the north it is delimited by the depression area

of Dornelor and Bargaului Mountains; to the east - the series of depressions: Şaru Dornei,

Păltiniş, Bilbor, Secu separates it from Bistrita Mountains. To the southeast are bounded by

Gurghiului Mountains. The southern limit is given by the Mureş defile that separates the

Gurghiului Volcanic Mountains. In the west, the hillsides of Caliman make the passage to the

Transylvanian Plateau.




Material and methods

The methodology for this

study comprised two major stages.

The first stage consisted in the

preparation of the cartographic

material and the extraction of all the

elements that are necessary in

studying the morphometry of the

hydrographic networks. The second

stage analyzed the main

morphometric elements of a

hydrographic basin.

The geomorphologic aspects

were obtained with the Digital

Elevation Model (DEM), prepared

from SRTM (Shuttle Radar

Topography Mission) with a

resolution of 25 m. For the correction

and validation of the obtained data we used topographic maps with a scale of 1: 25,000 and

satellite images provided by Google-maps, and the National Agency for Cadastre and Real Estate

Advertising (ANCPI).

For the preparation of the cartographic material and for the morphometric elements

analysis (surface, perimeter, density, slope, etc.) we used ArcGIS 10.5.

Results and discussion Extracting the drainage network from DEM was carried out in three stages:

- correcting errors that may occur in DEM by filling the existing gaps in the pattern or leveling

the unnatural peaks in DEM; this is done by running the ArcToolbox - Spatial Analyst Tools-

Hydrology – Fill;

- determining the flow direction which is set by the direction of the steepest descent, or the

maximum drop, from each cell. This is calculated as follows: maximum drop =

change_in_z-value / distance * 100 with the help of ArcToolbox - Spatial Analyst Tools-

Hydrology- Flow Direction

- calculating possible flow accumulations:

this tool calculates the accumulated flow

as the sum of all the cells flowing in each

Fig.3 Coding the flow direction

Fig.4 Determining possible accumulation

Fig.1 Calimani Mountains Positioning

Fig.2 Profile view of a sink before and after running Fill and Profile view of a peak before and after running Fill




descending cell in the output raster. Thus, the cell that does not receive water from the other

cells receives the value 1, and for cells that receive water from multiple sources, they are

added together with the value 1. In order to obtain the raster, use the command ArcToolbox -

Spatial Analyst Tools- Hydrology - Flow Accumulation

- The Flow Accumulation tool calculates accumulated flow as the accumulated weight of

all cells flowing into each downslope cell in the output raster. If no weight raster is

provided, a weight of 1 is applied to each cell, and the value of cells in the output raster is

the number of cells that flow into each cell (http://desktop.arcgis.com/en/).

- previous results can be reclassified to remove insignificant water streams. The range of

values of the raster overlapping on the analyzed territory is 0-5.41. By comparative analysis

with topographic maps with the scale of 1: 25000, some water courses were eliminated,

considered insignificant, ie non-permanent water courses. Using the Raster Calculator tool,

the values between 0 and 1.8 were removed, with the help of "Flow_Accumulation" = 1.8,

"Flow_Accumulation"), meaning that all cells with an equal or lower value than 1.8 were

eliminated. Finally, the hydrographic network from the entire analyzed area was obtained.

- this method is very fast, making the

time necessary for these analyzes

very effective, the errors being

very small. Their removal was

done manually by deleting the

extra generated points.

- the last step is delimitating the

river basins. To obtain this, the

accumulation points were

determined in a new shapefile file.

The points were positioned at the

extremity of the analyzed territory

in order to enclose the possible maximum. Non-enclosed areas are very small, which actually

represent small fragments of the hydrographic basins that do not have their development on

Fig.5 Determinarea acumularii posibile

RECLASSIFY

Fig.6 Errors in generating the hydrographic network

http://pro.arcgis.com/en/pro-app/tool-reference/spatial-analyst/flow-accumulation.htm

http://desktop.arcgis.com/en/




the territory of Calimani Mountains. The command used in ArcGIS to set the limits of river

basins is: ArcToolbox - Spatial Analyst Tools – Hydrology –Watershed

When you delimit

hydrographic basins or map

the hydrographic network, go

through a series of steps.

Certain steps are mandatory,

while others are optional

depending on the

characteristics of the input

data. The drainage direction

of a stream will always be to

the lowest cell. Once the

direction in each cell is

known, it is possible to

determine which and how

many cells flow in any given

cell. This information can be

used to define the boundaries (limits) of the river basin and the hydrographic network. The

following diagram shows the process of extracting hydrological information such as river basin

boundaries and hydrographic network from a digital terrain model (DEM).

Fig.8 The hydrographic network of Calimani Mountains

Morphometric elements of the hydrographic basins

Fig.7 Flowchart shows the process of extracting hydrologic

information (http://webhelp.esri.com)




The peculiarities of hydrological processes and phenomena in a hydrographic basin are

determined by the features it represents, namely: surface, length, width, shape, maximum

altitude, minimum altitude, etc..

The surface of the

hydrographic basin is the size of

the territory from which a

mainstream collects its water.On

the analyzed area there were

identified 6 hydrographic basins

with surfaces over 50 km2, 4 with

surfaces between 30-50 km2, 3

with 20-30 km2, the most

numerous being the small ones at

the extremity of the massif , i.e.

10 with surfaces between 10-20

km2 and 17 with surfaces under 10

km2, totalling 40 hydrographic

basins. The hydrographic basins

smaller than 2 km2 resulting from

these processes were excluded from the morphological analysis.

The surface of the hydrographic basin is one of the basin morphometric indexes

commonly used in hydrologic studies due to its important role in water flow. Thus, the lower the

reception basin, the better the hydrological regime of the river reflects the contribution of the

supply sources (pluvial and nival). With the increase of the surface, the effect of precipitation

and melting of the snow layer is slower and the flow variabilitymore attenuated (Pișotă I, Zaharia

Liliana, 2003).

The watershed is the line separating neighbouring hydrographic basins, linking the

highest elevation points. In a plan, this is the perimeter of the hydrographic basin, with a very

important role in calculating the hydrographic basin coefficient. The coefficient of development

of the catchment of the basin, introduced by Cebotarev, indicates the shape of the basin and is

calculated as follows: Kcum = Lc / Pc where Lc is the length of the catchment of the

hydrographic basin and Pc is the perimeter of the circle with a surface equal to the surface of the

basin.

The length of the basin, although is an important element

in characterizing the size of the river basins, its obtained values

are not always conclusive. In practice, this parameter is used to

show the distance between the point of sinking or confluence and

a point on the watershed, in the direction of the spring(Zăvoianu

I, 2006). Two parameters are used:

- The maximum length (Lmax), as the distance between the

river‘s spring and the spill, measured parallel to the main

drainage line.

- The average length (Lm) as the ratio between the surface of the

basin (Fb) and its width (B): Lm = Fb / B

The width of the river basin, as well as its length, is a

morphometric parameter used in defining the shape of the basin.

Fig.9 Surfaces and perimeters of hydrographic basins

Fig.10 Main components of the

hydrographic basin




We can consider a maximum width and an average width. The maximum width is considered to

be the line joining the furthest points, perpendicular to the length of the basin. The average width

is the ratio between the surface and the length of the hydrographic basin lmed = F / L.

The form factor

RE. Horton considers that a normally developed basin must be in the shape of a pear.

Horton proposed the form factor (Ff), having a square as a reference form, calculated according

to formula:

𝐹𝑓 =𝐹

𝐹𝑝²

where: F is the surface of the hydrographic basin and Fp is the area of the square whose side is

equal to the maximum length of the basin.

In 1953, V.C. Miller proposed, for the appreciation of the shape of the basin, the

circularity ratio (β) or the degree of deviation from the circular shape. That is, the ratio between

the perimeter of the circle (Lc) which has the same surface as that of the hydrographic basin and

its perimeter (Lp). It is obtained with the equation:

𝛽 =𝐿𝑐

𝐿𝑝=2 𝜋𝐹

𝐿𝑝

A circular basin has a maximum efficiency of the movement of runoff, whereas an

elongated basin has the least frequency.

The elongation ratio (Ra), Gravelius and Schumm proposed the circle as the reference

form, but the elongation ratio was defined by the ratio of the circle diameter with the same

surface as the basin (Dc) and the maximum length of the basin (Lb).

𝑅𝑎 =𝐷𝑐

𝐿𝑏Dc= 2 π r r=C / 2 π

Depending on this coefficient, we can have four types of basins: a slightly elongated

basin, where Ra is between 1.12 and 1.20, a moderately elongated basin, where Ra is between

1.20 and 1.30, a heavily elongated basin, where Ra is between 1.30 and 1.50 , a very elongated

basin, where Ra is over 1.50.

The altitude of the hydrographic basin is a morphometric parameter with a particular

influence on hydrological processes. Nearly all meteorological phenomena depend on it, which

then reflects on the characteristics of the hydrological elements (Pișotă I, Zaharia Liliana,2003).

In characterising a hydrographic basin from an altimetric point of view, the following parameters

can be used: maximum altitude, minimum altitude (corresponding to the main river's spout) and

average altitude.

The average altitude of the basin (Hm) is a very important parameter used to highlight

the particularities of the

genesis and water regime,

the evapo-transpiration and

the flow coefficient, in

relation to the average

altitude of the basins. It

shows at what average

altitude the surface of the

basin is situated in

comparison to the sea

level(Zăvoianu I, 2006). In

Fig.11 Average altitude




this case, the GIS software was used to automatically determine the average altitude.

The average altitudes of the river basins exceed 800 meters, specific to the mountainous

area. Their layout is closely related to the density of the hydrographic network. Thus, just like in

the case of density, the highest values of the average slopes are prevalent in the north-eastern

part of the massif, in the area of the volcanic caldera.

The morphometry of the hydrographic network

The length of the rivers is given by the distance (L), in km, measured along the water

flow from the spring to the the spill. The total length refers both to the main course and to its

tributaries.

𝐿 = 𝐿𝑝 + 𝑙𝑖

𝑛

𝑖=1

The density of the hydrographic network (D) conditions the capacity of rivers to collect

and drain rainwater as well as that of the underground waters. The density of the hydrographic

network is even more reduced if the terrain is harder and more resistant to erosion (granites,

gnose, etc.), while for lands such as clays it is enough to have a low flow to develop a drainage

network with a high density. Very permeable terrains (sands, gravel) determine a low density of

the hydrographic network due to rapid infiltration, while the practically impermeable terrain

determines a high value of its density (Scradaneanu, D., Gheorghe AI., 2007). It is calculated by

considering the ration between the total length of the watercourses and the surface of the river

basin:

𝐷 =Ʃ𝐿𝑐

𝐹𝑏𝑘𝑚/𝑘𝑚²

where: ΣLc is the sum of the lengths of all water courses and Fb is the surface of the river basin

Fig.12 Drainage density




The density of the hydrographic network with a permanent flow regime (see annex) is a uniform

one, most of the basins being in the range of 1-1.3 km /km2

. The hydrographic basins with the

highest density are found in the western extremity of the massif (Budusel, Bridiceasa and

Pietroasa) and in the southeast of the analyzed area (Calimanel, Giristea, Dusa). The lowest

density is prevalent in the north of the Calimani Mountains. Values lower than 1 km / km2 are

found in the elongated basins, these basins having a predominant development near the main

course (Bucinisul, Bauca, Panulet). The average density is found on the largest surface of the

massif, being characteristic to the large and very large basins (Rastolita, Ilva, Lomas)

Conclusions

The morphometry of river basins is understood as a quantitative analysis of the relief

elements. This type of analysis allows the identification of important general characteristics in a

basin, especially when considering the relation between geomorphological characteristics and

hydrographic network. Thus, morphometric analysis plays an important role in hydrographic

studies as it allows a systematic assessment of the physical aspects of a basin and a better

understanding of resource dynamics.

Remote sensing and GIS tools are effective techniques in hydrographic network

extraction using digital terrain models (DEM). The results are closely related to DEM quality

and resolution, a quality that has grown in recent years, fact that enhances such studies. The

hydrological analysis carried out for the hydrographic basins located on the Calimani massif

confirms that the hydrographic basins have characteristics specific to the mountainous areas. The

vast majority of hydrographic networks in large basins have a predominantly dendritic,

homogeneous type, and contribute to understanding land parameters such as flow, infiltration

capacity, etc..

BIBLIOGRAPHY

1. Grudnicki F. & Ciornei I. (2007) Amenajarea Bazinelor Hidrografice Torentiale prin

Lucrari Specifice. Universitatea Stefan cel Mare. Suceava.

2. Horton RE (1932) Drainage basin characteristics Trans Am Geophysics Union.

3. Horton, R.E. (1945), Erosional Development of Streams and their Drainage Basins

"Hydro-Physical Approach to Quantitative Morphology", Bull. Geol. Soc. America 56

(1945)

4. Oyatayo Kehinde Taofik, Bello Innocent, Ndabula Christopher, Godwill Geofrey

Jidauna, Ademola Sunday James(2017) A Comparative Analysis of Drainage

Morphometry on Hydrologic Characteristics of Kereke and Ukoghor Basins on Flood

Vulnerability in Makurdi Town, Nigeria. Hydrology. Vol. 5, No. 3, 2017, pp. 32-40. doi:

10.11648/j.hyd.20170503.11

5. Pișotă I, Zaharia Liliana,(2003) Hidrologia uscatului, Bucureşti, Curs universitar,

6. Ritter, D.F., Kochel, R.C., and Miller, J.R., (1995), Process Geomorphology 3rd Ed.:

W.C. Brown Publishers, Dubuque, IA, 539 pp.

7. Scrădeanu , D., Gheorghe AI ., (2007), Hidrogeologie generală , Editura Universitătii

Bucuresti

8. Strahler, A.N. (1952), Quantitative Geomorphology of Erosional Landscapes, 19th

International Geological Congress, Algiers, Sec. 13, pp.341-359.




9. Zăvoianu I,(2006) Hidrologie, Ediţia A IV-a, Ed. Fundaţiei România de mâine, Bucureşti,

2006,

10. Site ESRI - ArcGIS Online Help, http://desktop.arcgis.com/en/,

Annex

Den. bazin Fb Pc Pb Lb lb A.m

i

A.ma

x

A.med Pm Lc den β Kcu

m

Barzeta Mare 4.85 7.81 11.91

4.94 1.27 763 1478 1096.82

32.41

6.02 1.24

0.66

1.53

Bauca 8.5 10.34

13.99

5.61 2.56 1028 1991 1511.77

32.46

7.75 0.91

0.74

1.35

Bistra 92.16 34.03

42.97

13.36

10.02

568 1587 1134.07

31.18

112.94

1.23

0.79

1.26

Bistricioara 7.23 9.53 14.35

4.48 2.45 967 1464 1191.93

31.51

8.86 1.23

0.66

1.51

Bistrita 55.79 26.48

36.23

10.21

8.42 634 1581 1146.96

34.91

67.31 1.21

0.73

1.37

Borcurul 13.44 13 16.36

5.56 4.19 963 1489 1209.58

29.15

15.87 1.18

0.79

1.26

Bridiceasa 4.62 7.62 10.19

3.75 1.96 634 1122 849.26 29.42

7.16 1.55

0.75

1.34

Bucinisul 15.08 13.77

20.13

8.41 2.95 991 1850 1386.94

24.4 13.08 0.87

0.68

1.46

Budacul 40.84 22.66

30.05

9.69 6.03 759 1566 1232.11

28.86

51.06 1.25

0.75

1.33

Budusel 9.05 10.67

13.07

4.84 2.44 865 1494 1208.88

31.63

15.31 1.69

0.82

1.22

Calimanelul L 22.89 16.96

27.66

10.46

3.82 690 1333 999.94 24.79

28.96 1.27

0.61

1.63

Calimanelul T 13.7 13.1

2

21.3

4

8.42 2.36 702 1224 919.32 21.9

8

17.82 1.3 0.6

1

1.63

Dorna 45.78 23.99

28.9 9.61 6.39 1106 1931 1477.79

31.74

55.61 1.21

0.83

1.2

Dusa 6.12 8.77 12.35

4.76 1.86 662 1122 911.45 27.76

8.08 1.32

0.71

1.41

Fantanelul 12.1 12.3

3

18.8

7

5.28 4.63 614 1066 900.97 18.0

7

15.36 1.2

7

0.6

5

1.53

Galaoaia 34.89 20.94

27.72

10.73

4.54 541 1475 1071.46

29.71

40.23 1.15

0.76

1.32

Gioristea 15.28 13.86

18.74

5.84 3.92 654 1122 820.64 15.23

21.66 1.42

0.74

1.35

Ilva 125.7

2

39.7

5

54.5

2

19.4 11.3

8

605 2054 1225.4

6

34.8

3

151.0

2

1.2 0.7

3

1.37

Jingul

Niculesti

5 7.93 11.97

4.84 1.59 633 1169 947.46 30.09

5.9 1.18

0.66

1.51

Lomas 152.94

43.84

61.25

19.13

13.23

730 2010 1243.81

23.09

183.28

1.2 0.72

1.4

Mermezeu 12.5 12.5

3

19.5

3

7.94 2.35 665 1261 935.58 31 14.75 1.1

8

0.6

4

1.56

Neagra 92.55 34.1 41 13.94

9.57 1040 2055 1491 33.89

100.59

1.09

0.83

1.2

Neagra Calin 5.66 8.43 11.19

4.43 2.34 632 1155 968.89 31.03

6.64 1.17

0.75

1.33

Neagra II 45.89 24.0

2

37.7

7

12.2

8

7.95 1030 2013 1368.8

9

19.1

7

51.76 1.1

3

0.6

4

1.57

Negrisoara 10.95 11.73

14.18

4.28 4.02 1166 1844 1505.39

34.51

10.41 0.95

0.83

1.21

http://desktop.arcgis.com/en/




Panulet 8.51 10.3

4

14.7

8

5.29 2.83 1004 1587 1410.1

4

18.9

4

8.59 1.0

1

0.7 1.43

Paraul cu

Pesti

7.61 9.78 12.85

5.16 2.08 1034 1742 1402.34

33.67

9.19 1.21

0.76

1.31

Paraul Negru 10.61 11.55

15.45

5 3.87 983 1534 1302.7 21.92

11.82 1.11

0.75

1.34

Paraul Rusilor 3 6.14 7.9 3.12 1.71 979 1295 1126.81

19.6 3.78 1.26

0.78

1.29

Pietroasa 19.1 15.5 18.16

6.24 4.49 659 1496 1014.62

32.37

25.19 1.32

0.85

1.17

Porcul 4.29 7.34 11.24

4.79 1.53 672 1225 998.94 29.52

5.28 1.23

0.65

1.53

Rastolita 159.97

44.84

61.78

17.76

15.6 562 1969 1176.99

32.76

196.67

1.23

0.73

1.38

Runcul 3.28 6.42 9.6 3.85 1.28 785 916 854.45 12.04

3.94 1.2 0.67

1.5

Taietura 5.51 8.32 10.2 4.03 2.36 1034 1671 1323.3 26.65

6.22 1.13

0.82

1.23

Tarcani 2.32 5.4 9.9 4.4 0.97 1041 1711 1347.23

22.31

2.93 1.26

0.55

1.83

Tilimiul de

Sus

7.33 9.6 12.37

3.26 3.1 999 1877 1315.7 32.63

7.25 0.99

0.78

1.29

Tomnaticul 27.2 18.49

32.21

10.58

4.27 1033 1992 1439.22

16.42

30.22 1.11

0.57

1.74

Visa 7.66 9.81 16.42

6.62 2.16 595 1303 987.99 30.13

7.77 1.02

0.6 1.67

Vorova 14.08 13.3 15.77

5.18 4.34 1166 1862 1510.42

31.28

15.27 1.08

0.84

1.19

Zebrac 22.92 16.97

24.01

8.8 3.87 651 1480 977.32 30.77

25.81 1.13

0.71

1.41

Fb - basin surface, Pc – circle perimeter, Pb - basin perimeter, Lb - basin length, lb - basin width, A.min -

minimum altitude, A.max - maximum altitude, A.med - average altitude, Pm – average slope, Lc - Length

of watercourses, den - density, β - circularity coefficient, Kcum – the development coefficient of the

watershed

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