MORPHOMETRIC ANALYSIS OF KHULGAD WATERSHED … · drainage basin (Strahler 1964). Drainage basin...

DOI:10.21884/IJMTER.2018.5025.GPMKR 162

MORPHOMETRIC ANALYSIS OF KHULGAD WATERSHED ALMORA,

UTTARAKHAND

Zainab Fatima1

1Interdisciplinary Dept. of Remote Sensing and GIs Application Aligarh Muslim University Aligarh

Abstract-Rivers are the dynamic and increasingly important part of the physical environment Rivers

usually has well-defined spatial boundaries and these are the medium of energy exchange from one

place to another place in external environment. Morphometry is the measurement and mathematical

analysis of earth‟s surface, features, forms and the dimension of the landforms. Morphometric analysis

requires measurement of linear features, aerial aspects and gradient of channel network of the drainage

basin. Morphometric parameters are relevant and useful to identify various hydraulic characteristics of

drainage basin i.e. patterns, shape, stage of stream, permeability of bed rock, health of streams, as well

as help to correlate with lithological characteristics. The study area, is the Khulgad Watershed

(29°34′30.20″– 29°38′48.03″N lat. and 79°32′20.71″–79°37′11.19″E long.) lies 15 km north-west of

Almora township in the Khulgad watershed of Kosi River. The GIS based Morphometric analysis of this

drainage basin revealed that the Khulgad watershed is 6th order drainage basin and drainage pattern

mainly is dendritic type thereby indicates homogeneity in texture and lack of structural control and The

dendritic pattern of drainage indicates that the soil is semi pervious in nature. Total number of streams is

929, in which 711 are first order, 173 are second order, 33 are third order and 9 are fourth order streams

2 are fifth order streams and 1 is sixth order stream. The length of stream segment is maximum for first

order stream and decreases as the stream order increases. The drainage density (Dd) of study area is 0.80

and mean bifurcation ratio is 19.52 .This study would help the local people to utilize the resources for

sustainable development of the basin area.

I. INTRODUCTION

Morphometric analysis of a watershed provides a quantitative description of the drainage system,

which is an important aspect of the characterization of watersheds (Strahler, 1964). Morphometric

descriptors represent relatively simple approaches to describe basin processes and to compare basin

characteristics (Mesa 2006) and enable an enhanced understanding of the geomorphic history of a

drainage basin (Strahler 1964).

Drainage basin morphometric parameters can be used to describe the basin characteristics. These

are basin size (stream order, stream length, stream number, and basin area), bifurcation ratios, drainage

density. The risk factor of flood is indirectly related with the bifurcation ratio (Waugh 1996).

Quantitative expression of drainage basin shape or outline form was made by Horton (1932) through a

form factor.

1.1 Statement of the problem

The study of rivers and their works has an important place in geomorphology, especially in

fluvial geomorphology. The river channels play a key role in the development of fluvial landforms.

These parameters have been used in various studies of fluvial geomorphology and surface-water

hydrology, such as flood characteristics, sediment yield, and evolution of basin morphology, risk

assessment and vulnerability etc.

International Journal of Modern Trends in Engineering and Research (IJMTER)

Volume 05, Issue 1, [January– 2018] ISSN (Online):2349–9745; ISSN (Print):2393-8161

@IJMTER-2018, All rights Reserved 163

II. REVIEW OF LITERATURE

In order to model the hydrological processes in a multi-vegetated watershed it is necessary to

update the information regarding the response of these processes to various watershed parameters.

This quantitative Morphometric analysis of watersheds was continued by a series of

methodological and theoretical papers spanning more than a quarter century (Langbein 1947; Schumm

1956). Jamieson et al (2004) showed that tectonic zones in the Indus Valley of Ladakh, in north India,

can be differentiated using morphometric analyses of longitudinal valleys.

Morphometric analysis through remote sensing and GIS techniques have been attempted by a

number of researchers (Nautiyal, 1994; Srivastava, 1997; Nag, 1998; Agarwal, 1998; Biswas, et al.,

1999; Singh et al., 1997; Vittala et al 2004; Reddy et al., 2004) and all have arrived to the conclusion

that remote sensing and GIS are the powerful tools for studying basin morphometry and continuous

monitoring. Ajoy Das et al (2012) have used remote Sensing and GIS techniques for generation of

various thematic maps such as geomorphology, drainage, watershed and surface water, landuse/land

cover, soil and slope. These maps were used for prioritization of mini watersheds through morphometric

analysis.

Nageswara Rao (2010) carried out morphometric analysis of the Gostani River Basin in Andhra

Pradesh using Spatial Information Technology (SIT) in the delineation of drainage pattern and for water

resources management and planning. The basin morphometric parameters such as linear and aerial

aspects of the river basin were determined and computed. The area is occupied by 96% khondalite group

(quartz, feldspar, garnet sillimanite gneiss) of rocks. It is a 7th order drainage basin and observed that

the drainage density is low which indicates the basin is highly permeable subsoil and thick vegetative

cover. The circularity ratio value reveals that the basin is strongly elongated and highly permeable

homogenous geologic materials. This study would help the local people to utilize the resources for

sustainable development of the basin area.

Markose and Jayappa (2012) have investigated the influence of tectonic activity in Kali river

basin, southwest coast of India through an analysis of the geomorphic indices computed through GIS.

There are five geomorphic indices such as stream length gradient index, asymmetry factor, hypsometric

integral, valley floor width-to-height ratio, and elongation ratio were utilized for identification of

evidences of tectonic activity. The results obtained from these indices were combined to develop an

index of relative tectonic activity classes. The relative tectonic activity shows low and medium values,

which indicate the highest degree of tectonic activity compared to the upland plateau regions.

III. OBJECTIVES

The present study on morphometric analysis of Khulgad Watershed using ASTER data and GIS

techniques aims to,

1. Identify drainage bifurcation system and their nature.

2. Understand the Morphometric Parameters‟ behavior of the area.

3. Prioritize the watershed through morphometric parameters and present land use

4. Study Area

IV. GEOGRAPHICAL AREA

The study area, viz. the Khulgad Watershed (29°34′30.20″– 29°38′48.03″N lat. and

79°32′20.71″–79°37′11.19″E long.) lies 15 km north-west of Almora township in the Khulgad

watershed of Kosi River. Khulgad watershed encompassing an area of 32 km^2 within altitude 1150 m

and 2190 m, having cool temperate climate with an annual average temperature of 20C and an annual

average rainfall of 935 mm. Geomorphological, the landform are mature, valleys are fluvially eroded

and are unusually wide, with terraces and alluvial fans (Rai,1993). On the basis of land use, Khulgad




watershed is divisible into 8 areas (rawat, 1992). About 26% area of the watershed is under poorly

managed agriculture, 31% under unrestricted grazing, 4% under horticulture, and nearly 39% is covered

by forest of oak and pine

Almora is situated on a horseshoe ridge of mountain, the eastern portion of which is called talifat

and the western one is called as selifat. Kosi River flows through Almora district. It is famous for its

beauty and views of Himalayas, cultural heritage.

Map 1: Location Map of Khulgad Watershed

V. DATA SOURCE AND METHODOLOGY

The present study integrated the use of remote sensing and GIS techniques in morphometric

analysis, and the results of morphometric parameters determined are briefly described and discussed.

The study of basin morphometry attempts to relate basin and stream network geometries to the

transmission of water and sediment through the basin. The size of a drainage basin acts upon the amount




of water yield, the length, shape and relief, affect the rate at which water is discharged from the basin.

The morphometric analysis is carried out with respect to the parameters like stream order, stream length,

bifurcation ratio, stream length ratio, basin length, drainage density, stream frequency, elongation ratio,

circularity ratio, form factor, and relief ratio using mathematical formulae.

Morphometric analysis of the watershed Morphometry is the measurement and mathematical

analysis of the configuration of the earth's surface, shape and dimension of its landforms (Agarwal,

1998; Obi Reddy et al., 2002). A major emphasis in geomorphology over the past several decades has

been on the development of quantitative physiographic methods to describe the evolution and behavior

of surface drainage networks (Horton, 1945; Leopold & Maddock, 1953; Abrahams, 1984). Different

morphometric techniques, like absolute relief, relative relief, dissection index, average slope, drainage

density and ruggedness index are considered for quantitative analysis of different attribute of the

watershed. A point layer is generated in the ArcGIS s/w environment and the spot heights are collected

according to the longitudinal and latitudinal value. Then spot height attribute for each sample location is

introduced to the point layer. All point data are interpolated to the raster through krigging interpolation

(Matheron, 1970) techniques in the ArcGIS s/w environment. Both interpolated and surfacing outputs

are merged to create raster digital elevation model (DEM) for the Khulgad watershed.

5.1 Methodology

A systematic approach involving multiple steps is necessary for the spectacular working style. In

the present study, it begins with review of literature and collection of information/ data about the study

area. Afterwards, the various steps taken under consideration while preparing the useful datasets for the

present study are as follows, shown in mentioned flow chart. However, in terms of pre-processing, other

useful steps such as geo-referencing, rectification, geometric corrections to retain spatial distortions

within the dataset are also taken under consideration

5.2 Generation of Digital Elevation Model (DEM)

The digital elevation data for the study area was downloaded from

(http:/ /www.gdem.aster.ersdac.or.jp/search.jsp). The ASTER GDEM is 1x1 tiles in GEOTIFF

format with lat-long coordinates and a 1 arc-second (30 m) grid of elevation posting and referenced to

the WGS84 datum and vertically referenced to WGS84 EGM 96 Geoid. The horizontal and vertical

accuracy has been reported to be less than 30 and 20 meters respectively with 95% accuracy.

Filling sinks: When delineating stream networks form DEMs, it is necessary to fill sinks. A sink is a cell

or set of spatially connected cells whose flow direction cannot be assigned to one of the eight valid

values in a flow direction grid. This can occur when all neighboring cells are higher than the processing

cell, or when two cells flow in to each other creating a two-cell loop(ESRI2009). Sinks in the DEM

were filled up with the FILL function. It is an iterative process that goes to each cell and fills the sinks

by comparing the value of neighboring cells until all the sinks are filled. Even though creating a

depression less DEM was the goal, sinks were minimized to 0.1 million cells from 3.6 million.

Generation of flow direction: The direction of flow was determined by finding the direction of steepest

descent from each cell. This was calculated as: maximize drop = (change in z-value)/ (distance)ˆ100.

The distance is determined between cell centers. Therefore, if the cell size is 1, the distance between two

orthogonal cells is 1 and the distance between two diagonal cells is 1.414. If the descent to all adjacent

cells is the same, the neighborhood is enlarged until a steepest descent is found (ESRI 2009). The

function FLOWDIRECTION was used to calculate the direction of flow of each cell.

Generation of flow accumulation: Flow accumulation represents the accumulated flow in each grid

cell. It was calculated by using flow direction and by counting the number of cells flowing to a particular

cell. Thus, flow accumulation represents the number of upstream cells of any cell in an area. The

http://www.gdem.aster.ersdac.or.jp/search.jsp




FLOWACCUMULATION function was used to calculate this automatically while it takes the flow

direction grid as input.

Generation of stream network: A set of thresholds of 10, 100 and 1000 pixels were used to generate

stream network. All the cells in the flow accumulation grid that were above or equal to those threshold

values were identified to generate raster linear networks. The output grids were then vectorized using the

STREAMLINE function of ArcGIS, which takes raster linear networks and flow direction raster as input

to produce linear vectors that also show the direction of flow (Figure 3). Once the streams were

accurately derived, the watersheds (sub-basins) were delineated using available pour point.

Generation of watersheds: Pour point was generated to derive the sixth order stream network for the

entire study area. Strahler‟s stream ordering method was used to categorize streams in to different orders

based on the location of stream from stream head to tail of the watershed

VI. RESULT AND DISCUSSION

Morphometric analysis, which is all about exploring the mathematical relationships between

various stream attributes, used to compare streams and to identify factors that may be causing

differences. The term Morphometric is derived from a Greek word, where “morph” means earth and

“metry” means measurement, so together it is measurement of earth features. This is an important factor

for planning any watershed development. Morphometric analysis also provides description of physical

characteristics of the watershed which are useful for environmental studies, such as in the areas of land

use.

Map 2: Digital Elevation Model




Quantitative assessment of these drainage parameters has been carried out using standard

mathematical formulae given by Chopra et.al (2005), which are tabulated in Table 1

Morphometric

Parameters

Formula Reference

Stream order (u) Hierarchail rank Strahler(1964)

Stream length (Lu) Length of streams Horton (1945)

Mean stream length

(Lsm)

Lsm = Lu/Nu

Where, Lsm = Mean

stream length Lu = Total

stream length of order

„u‟

Nu = Total no. of

streams segments of

order „u‟

Strahler(1964)

Stream length ratio (RL) RL = Lu/Lu1

Where, RL = Stream

length ratio

Lu = Total stream

length of order „u‟

Lu1 = Total

stream length of its next

lower order

Horton (1945)

Bifurcation ratio (Rb) Rb = Nu/Nu1

Where, Rb = Bifurcation

ratio

Nu = Total no. of

stream segments of order

„u‟

Nu1= No. of

segments of the next

higher order

Schumn (1956)

Drainage density (D) D = Lu/A

Where, D = Drainage

density

Lu = Total stream

length of all orders

A = Area of the

basin (Km2)

Horton (1932)




DEM is an important step in delineating any morphometric parameters. The first step in any

hydrologic Modelling is to fill the elevation grid.

Map 3: Fill sink




Morphometric analysis for the present study is grouped into three classes such as linear aspects,

areal aspects and relief aspects.

6. 1 Stream Order (Su)

The order of the stream is based on the connection of tributaries. Stream order is used to

represent the hierarchical link among stream segments and allows drainage basins to be classified

according to size. Stream order is a fundamental property of stream networks as it relates to the relative

discharge of a channel segment.

A number of stream-ordering systems in the present study have been used which was formulated

by Arthur N. Strahler. According to the analysis, first order streams are having no stream tributaries and

that flows from the stream source. A second-order segment is created by joining two first-order

segments, a third-order segment by joining two second order segments, and so on. There is no increase

in order when a segment of one order is connected by some other lower order. Strahler stream order has

been applied by many researchers for river systems.

The highest stream order observed in the present study area is sixth order out of 929 observed

streams. 711 first order, 173 second order, 33 third order 9 fourth order 2 fifth order and 1 sixth order

streams were observed. Dendritic drainage pattern formed by the interlinking of streams is observed in

the study area which indicates the homogeneity in texture and lack of structural control.

Dendritic drainage has a spreading, tree-like pattern with an irregular branching of tributaries in

many directions and with any angle. It is observed that the maximum frequency is in case of first order

streams. It is noticed that there is a decrease in stream frequency as the stream order increase.

Table: 2 Stream Ordering

6.2 Stream Number (Nu)

The count of stream channel in given order is termed as stream number. Horton‟s law states that

“the number of streams of different orders in a given basin tends closely to approximate as inverse

geometric series of which the first term is unity and the ratio is the bifurcation ratio”. The stream

frequency is inversely proportional to stream order and stream number is directly proportional to size of

contributing basin and to the channel dimension.

Higher the stream number indicates lesser permeability and infiltration. It leads to inference that

several stream usually upsurges in geometric progression as stream order increases. The variations in

rock structure in the basin are responsible for disparity in steam frequencies of each other

Stream order No of streams

1st 711

2nd

173

3rd

33

4th 9

5th 2

6th 1




Map 4: Stream order

6.3 Stream Length (Lu)

Stream length is the total length of stream segment of each of the consecutive order in the basin

tends approximate a direct geometric series in which the first term is the average length of the first

order. It‟s the quantification of hydrological characteristics of bedrock and the drainage extent. When

bedrock is of permeable character then only subtle number of relatively longer streams is formed in a

well-drained basin area. On the other hand, when the bed rock is less permeable then large number of

smaller length of streams in the basin are produced.

Stream Order Stream Length

1st 900.74

2nd

413.51

3rd

187.03

4th

120.14

5th

112.03

6th

11.22




Table 3: Stream Length

6.4 Bifurcation Ratio (Rb)

Bifurcation Ratio (Rb) is defined as the ratio of the number of streams of any order to the number

of streams of the next highest order (Strahler 1957). Values of Rb typically range from the theoretical

minimum of 2 to around 6. Typically, the values range from 3 to 5. The bifurcation ratio is calculated as

3.9037

Rb = Higher Order + 1/Next Lower Order

Horton (1945) considered bifurcation ratio as an index of relief and dissection. According to

Strahler (1957), bifurcation ratio exhibit subtle fluctuation for different region with varied environment

except where powerful geological control dominates. According to Schumm (1956), bifurcation ratio is

the ratio of number of stream segment of given order to the number of segment in the next order, it is

dimensionless property and indicates the degree of integration prevailing between streams of various

orders in drainage basin . Strahler significantly marked that geological structures do not affect drainage

pattern for bifurcation ratio is in between 3.0 to 5.0. When bifurcation ratio is low, there will be high

possibilities of flooding as water will tend to accumulate rather than spreading out. The human

intervention plays important role to reduce bifurcation ratio which in turn augment the risk of flooding

within the basin, this was noted significantly by.

Stream Order Bifurcation Ratio

1st 4.10982659

2nd

5.24242424

3rd

3.66666667

4th

4.5

5th

2

6th

6.5 Drainage pattern of Khulgad watershed

The drainage pattern for the present study area is dendritic. The drainage pattern shows well

integrated pattern formed by a main stream with its tributaries branching and rebranching freely in all

direction. The dendritic pattern of drainage indicates that the soil is semi pervious in nature.

6.6 Drainage Density (D)

The drainage density (Horton 1932), D is the ratio of the total length of streams within a

watershed to the total area of the watershed; thus D has units of the reciprocal of length (1/L). A high

value of the drainage density would indicate a relatively high density of streams and thus a rapid storm

response.

Table: 11 Drainage density

Drainage density 0.80

Map 5: Drainage Density

Table: 7 Bifurcation ratio

The mean value of bifurcation value

is 3.9037835




Summary Table

S.no Stream

order

Stream

number

Stream

length

Mean

stream

length

Stream

length ratio

Bifurcation

ratio

1 1st 711 900.74 1.27 0.014 4.11

2 2nd

173 413.52 2.39 1.886 5.24

3 3rd

33 187.03 5.67 2.371 3.67

4 4th

9 120.14 13.35 2.355 4.50

5 5th

2 112.03 56.02 4.196 2.00

6 6th

1 11.22 11.22 0.200

Total 929 1744.67 89.92 11.023 19.52

Max basin length 84.40

Basin perimeter 364.10

Basin area 2188.80

Drainage density (D) 0.80

VII. CONCLUSION

Watershed is a basic unit for morphometric analysis. Remote sensing and GIS techniques are

known for providing very high accuracy in mapping and measurement done in morphometric analysis.

Stream ordering, stream length, stream order, bifurcation ratio, flow direction flow accumulation,

drainage density are the most useful criteria for the morphometric classification of a watershed.

Prominently drainage basin morphometry is significant approach that reflects existing

geomorphic process operating in fabric of a drainage basin. Drainage basin morphometry explicitly

reveals quantitative information on landform. In simple words, the quantitative evaluation of

morphometric parameters is essential tool in river basin analysis in terms of soil and water conservation

and natural resource management In regards to formation and development i.e. evolution of land surface

process depends on morphometric nature of basin. The morphometric assessment of drainage system is

imperative to any hydrological studies. Also, co-relation of stream network behavior plays significant

role. Therefore, various hydrological phenomena of drainage basin can be in relevance to size, shape of

drainage basin. Meticulous study of morphometry of all sub-basins reveals drainage pattern which

further infers to lithological nature. One can co-relate the morphometric nature of basin with the

sediment- yield coming from the basin, similarly, the aspect of morphometry can be linked with the flow

characteristics, sediment transports and fluvial process.

The study reveals that remotely sensed data (ASTER-DEM) and GIS based approach in

evaluation of drainage morphometric parameters and their influence on landforms, soils and eroded land

characteristics at river basin level is more appropriate than the conventional methods. GIS based

approach facilitates analysis of different morphometric parameters and to explore the relationship

between the drainage morphometry and properties of landforms, soils and eroded lands. Different

landforms were identified in the watershed based on ASTER (DEM) data with 30 m spatial resolution,

and GIS software. GIS techniques characterized by very high accuracy of mapping and measurement

prove to be a competent tool in morphometric analysis. The morphometric analyses were carried out

through measurement of linear, areal and relief aspects of the watershed with more than 85

morphometric parameters. The morphometric analysis of the drainage network of the watershed show

dendritic and radial patterns with moderate drainage texture. The variation in stream length ratio might




be due to change in slope and topography. The bifurcation ratio in the watershed indicates normal

watershed category and the presence of moderate drainage density suggesting that it has moderate

permeable sub-soil, and coarse drainage texture. The value of stream frequency indicate that the

watershed show positive correlation with increasing stream population with

Application of Remote Sensing and GIS technique in morphometric analysis for efficient

planning and management of drainage basin. The present study conducted in Khulgad watershed district

Almora Uttarakhand region advocates that remotely sensed data and GIS based approach in evaluation

of drainage morphometric parameters and analysis of land use and land cover, is more appropriate than

the conventional methods. GIS techniques characterized by very high accuracy of mapping and

measurement prove to be a competent tool in morphometric analysis of the study area covers, remotely

sensing technology reveals a very significant role, by multi-temporal interpretation of satellite data.

The digital elevation model (DEM) and slope map of the catchment area has been generated

from ASTER data of 30 m resolution shows that the elevation in the study area ranges between 241 to

2727 m.

The morphometric analyses were carried out through measurement of linear, areal and relief

aspects of the catchment area using standard morphometric parameters. The morphometric analysis of

the drainage network of the catchment area exhibits sub-dendritic drainage patterns with moderate

drainage texture. The variation in stream length ratio might be due to difference in slope and

topographic conditions. The variation of bifurcation ratio in the catchment area is ascribed to the

difference in topography and geometric development.

This variation in the value of bifurcation ratio reveals less structural control on the drainage

development. The presence of high drainage density suggests that the catchment area has impermeable

subsurface materials and mountainous relief. The stream frequency in the catchment area exhibit

positive correlation with the drainage density, indicating the increase in stream population with respect

to increase in drainage density.

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