Morphometric Analysis Of Drainage Basin Biology Essay

Morphometric analysis of a drainage basin demonstrates the dynamic equilibrium that has been achieved due to interaction between affair and energy. It helps to understand the prevailing geo-hydrological features of the drainage basins. In the present survey, morphometric analysis has been carried out utilizing distant detection and Geographical Information System ( GIS ) techniques to measure the geo-hydrological features of four sub-watersheds of Etmadpur country of Agra territory, Uttar Pradesh. The morphometric parametric quantities of the sub-watersheds are discussed with regard to linear, areal and relief facets. The Etmadpur watershed characterized by dendritic to sub-dendritic drainage form. The high values of Bifurcation Ratio ( Rb ) among all the sub-watersheds indicate the possibilities of structural control over the drainage form. The Circularity Ratio ( Rc ) values ranges from 0.20 to 0.62 ; while its value for B-II and B-III sub-watersheds indicate them to be about round and structurally influenced, whereas the for B-I and B-IV water partings are found in the order of less than 0.57 which indicates that the sub-watersheds are elongated 1s. The values of Elongation Ratio ( Re ) for these sub-watersheds vary from 0.36 to 0.73, proposing high alleviation and steep land incline. The values of Form Factor ( Rf ) for B-I and B-IV sub-watersheds are 0.18 and 0.10, severally ; whereas for B-II and B-III sub-watersheds, the Rf values are 0.40 and 0.42, severally. Therefore, it has been observed that B-I and B-IV sub-watersheds are elongated in form whereas B-II and B-III sub-watersheds are about round in form.

The morphometric analysis of the drainage basin and channel web play a critical function for understanding the geo-hydrological behaviour of drainage basin and expresses the prevailing clime, geology, geomorphology, structural, etc. ancestors of the catchment. The relationship between assorted drainage parametric quantities and the aforementioned factors are good recognized by many workers [ 1,2,3,4,5 ] . Recently, many research workers have used distant feeling informations and analyzed them on GIS platform for understanding the morphometric belongingss of the catchment [ 6,7,8 ] . The aim of the present survey is to analyse the morphometric properties of Yamuna river basin around Etmadpur tehsil of Agra territory as so far any systematic work on the morphometry of the part has non been carried out.

Etmadpur tehsil is a portion of fringy alluvial field and lies near to Yamuna river in the north-eastern portion of Agra and is located at a distance of 21.8 kilometers from Agra metropolis and about 101 kilometers from Etawah territory ( Fig. 1 ) . The major portion of the country is covered by Indo-Gangetic Quaternary alluvial sedimentations which excessively the stones of Vindhyan Supergroup. The survey country lies between the analogues of 27°5 ‘ and 27°20’N latitudes, 78°5 ‘ and 78°20’E longitudes.

Physiographically, the Agra territory is divided into five distinguishable parts viz. , Khadar lowland, Trans-Yamuna field, Yamuna highland, South-West Upland and Yamuna Chambal Ravines. The survey country has a long irregular land, narrow towards the appendages and reasonably broad in the Centre. Physical character of the units differs greatly from each other. The degree land between Yamuna and Chambal consists of mere ridge and narrow strip flanked on either side by ravines taking to the river.

The clime of the country is semi-arid and characterized by hot summer and temperature ranges every bit high as 47A°C during summers ( April to June ) . The monsoon months ( July to September ) receive about 152 centimeter of rainfall.

Geologically, the country is a portion of Indo-Gangetic field and characterized by alluvial sediment which is an concoction of crushed rock, sand, silt and clay in assorted proportions, deposited during the Quaternate period. The dirt of Agra is loose, flaxen and chalky. The stone units belong to the Vindhyan Supergroup represented by the upper Bhander and lower Rewa sandstones, exposed in the West and sou’-west of Agra in the signifier of structural hills. The top dirt in general is harsh and angular sand with little fraction of clay. However, in the survey country, the dirt is all right loam in cardinal portion, sandy in the northern portion and clayey in the southern portion. The general geological sequence of the survey country as given by is every bit followed [ 9 ] :

Generalized Geological Succession

Quaternate

Upper Pleistocene to Recent

Newer Alluvium

Older Alluvial sediment

Laterite and Clay

Sand and crushed rock

Sand, clay, silt and kanker

Laterite and Clay

Unconformity

Pre-Cambrian

Vindhyan Supergroup

( Upper Vindhyan )

Upper Bhander Sandstone

Lower Rewa Sandstone

Hard & A ; compact sandstone

Hard & A ; compact sandstone

Methodology

The drainage map ( Fig. 3 ) of the survey country has been prepared utilizing IRS-1D LISS-III Geo-coded False Colour Composites ( FCC ) ( bands 2, 3 and 4 ) ( 28 March, 2003 ) and corroborated with information on SOI topographical maps 54 I/3, 54 I/4, 54 I/7 and 54 I/8 on 1:50,000 graduated table with selected land truth. The morphometric parametric quantities of all the bomber water partings have been calculated utilizing GIS packages ( ArcGIS and ArcView ) . Perimeter and country of the bomber water partings are besides calculated online by the ‘measurement tool ‘ of ISRO Bhuvan orbiter informations ( at hypertext transfer protocol: //bhuvan2.nrsc.gov.in/ ) . Digital Elevation Model ( DEM ) information from Shuttle Radar Topographic Mission ( SRTM ) of 90m declaration ( on hypertext transfer protocol: //srtm.csir.cgiar.org/ ) of the survey country has been used in the present survey. The quantitative analysis of morphometric parametric quantities is given in Table-1 and the consequences summarized given in Table-2.

Consequences and Discussion

The survey of basin morphometry relates basin and watercourse web geometries to the transmittal of H2O and deposit through the basin. The size of a drainage basin acts upon the sum of H2O output ; the length, form and alleviation, affect the rate at which H2O is discharged from the basin and entire output of deposits. Systematic description of the geometry of a drainage basin and its watercourse channel requires measuring of additive facets of the drainage web, areal facets of the drainage basin, and alleviation ( gradient ) facets of the channel web and lending land inclines [ 10 ] . In the present survey, the morphometric analysis is carried out with regard to parametric quantities like watercourse order, watercourse length, bifurcation ratio, watercourse length ratio, basin length, drainage denseness, watercourse frequence, elongation ratio, disk shape ratio, signifier factor, alleviation ratio, etc. utilizing mathematical expression as given in Table-1 and the consequences are summarized in Table-2.

Linear Aspects

The additive facets of morphometric analysis of sub-watershed include stream order, watercourse length, average watercourse length, watercourse length ratio and bifurcation ratio.

Stream Order

The appellation of watercourse orders is the first measure in drainage basin analysis and expresses the hierarchal relationship between watercourse sections, their connectivity and the discharge eliciting from lending catchments. In the present survey, the watercourse ordination has been carried out utilizing Strahler method [ 10 ] . The order wise watercourse Numberss and length of four sub-watersheds are counted and listed in Table-2 which indicates that B-I, II, III and IV sub-watersheds have streams upto 4th order. The Numberss of watercourse sections present in each order are counted and it is observed that the figure of stream sections decreases as the watercourse order additions. This observation is in conformity with the Horton ‘s Law [ 1 ] . This jurisprudence is followed in the survey country and the geometric relationship is shown diagrammatically in the signifier of consecutive line when the log value of these variables ( stream order and watercourse figure ) and ( stream order and watercourse length ) plotted ( Fig.4 and Fig.5 ) , proposing the country to be in normal basin class.

Stream Length ( Lu )

The watercourse length is computed based on the Horton Law [ 1 ] for all the four sub-watersheds. The figure of watercourses of assorted order in the sub-watershed counted and their lengths are measured. In the survey country, entire length of watercourse sections is maximal for first order and decreases every bit stream order additions. This is a normal tendency and indicates that the terrain is gently inclining, low alleviation and homogeneous petrology. However, in all four sub-watersheds, the watercourse sections of assorted orders, varies well ( Table-2 ) .

Bifurcation Ratio ( Rb )

The bifurcation ratio is the ratio of the figure of stream sections of given order to the figure of sections of following higher order. Bifurcation ratio is an index of alleviation and dissection [ 1,11 ] . It is good demonstrated that bifurcation ratio shows a little scope of fluctuation for different parts or for different environment except where geological control dominates2. It has been found that the bifurcation ratio characteristically ranges between 3.0 and 5.0 for watershed in which geology is moderately homogenous and no structural perturbations.

Bifurcation ratio for different sub-watersheds of the survey country have been determined and given in Table-2. The incline of semi log secret plans of watercourse order vs. watercourse figure ( Fig.4 ) gives the bifurcation ratio. The abnormalities in the bifurcation ratios of the four sub-watersheds are perchance dependent upon the drainage basin [ 12 ] . The lower values of Rb indicate that the sub-watershed has suffered less structural perturbations [ 10 ] and the drainage form is non distorted. Furthermore, the low Rb values mean a high drainage denseness, low permeableness of the terrain and indicate countries with unvarying surficial stuffs where geology is moderately homogenous. The average bifurcation ratio, which is the norm of bifurcation ratios of all orders, varies from 4.4 to 6.4 ( Table -2 ) . The highest value of average bifurcation ratio is found in sub-watershed-IV suggesting structural control in the country and low permeableness whereas all other basins are geologically homogeneous. This besides suggests that the drainage basin morphometry of sub-watershed-IV may hold been affected by human activities.

Mean Stream Length ( Lsm )

The average watercourse length is calculated by spliting the entire watercourse length of given order and figure of watercourse of that order ( Table-2 and Fig.5 ) . In the survey country, it is noted that Lsm varies from 0.48 to 23.0 kilometers and its value for any given order is greater than that of the lower order and less than that of its following higher order in all the sub-watersheds except sub-watershed B-III, which is abnormally increased, perchance due to fluctuation in the incline and topography in this sub-watershed.

Stream Length Ratio ( RL )

The watercourse length ratio can be defined as the ratio of the average watercourse length of a given order to the average watercourse length of following lower order and holding of import relationship with surface flow and discharge [ 1 ] . Stream length ratio between the watercourses of different order in each sub-watershed of the survey country is variable ( Table-2 ) e.g. , sub-watershed B-II show an increasing tendency in the watercourse length ratio from lower order to next higher order which indicate their mature geomorphic phase whereas, sub-watersheds I and III show alterations in RL from one order to another which indicate the late young person to maturate phase of geomorphic development [ 13 ] .

Aerial Aspects

The aerial facets include drainage denseness, drainage texture, watercourse frequence, signifier factor, disk shape ratio, elongation ratio and length of overland flow. The consequences are summarized in Table-2 and discussed in following paragraphs.

Drain Density ( D )

The drainage denseness is an of import index of the additive graduated table of landform component in watercourse eroded topography and defines as the entire length of watercourse of all orders/drainage country and may be an look of the intimacy of spacing of channels [ 14 ] . The significance of drainage denseness is recognized as a factor finding the clip travel by H2O [ 15 ] .

The low drainage denseness is favored in parts of extremely permeable undersoil stuff, under heavy vegetive screen where alleviation is low, while high drainage denseness is favored in parts of weak or impermeable sub-surface stuffs, thin flora and high mountain alleviation. The low drainage denseness is besides declarative of comparatively long overland flow of surface H2O. The drainage denseness in the survey country is low ( Table -2 ) and varies from 1.95 to 2.89 km/km2, therefore indicates clearly that the part has extremely permeable undersoil, heavy flora screen and low alleviation. The drainage denseness factor is besides related with the clime, surface raggedness and overflow in the country of involvement.

Drain Texture ( Rt )

The drainage texture considered as one of the of import construct of geomorphology which show the comparative spacing of the drainage lines [ 1 ] . The drainage denseness less than 2 indicates really harsh, between 2 and 4 as coarse, between 4 and 6 as moderate, between 6 and 8 as mulct and greater than 8 as really all right drainage texture [ 16 ] . In the present survey, it was found that the drainage denseness values ( Table-2 ) are variable and suggests that the survey country falls into really harsh to coarse texture class and indicates good permeableness of sub-surface stuff in the survey country.

Stream Frequency ( Fs )

The watercourse frequence is defined as the entire figure of stream section of all order per unit country [ 14 ] . The watercourse frequence for all four sub-watersheds of the survey country show positive correlativity with the drainage denseness ( Fig.6 ) which indicates that the watercourse population additions with the addition of drainage denseness in all four sub-watersheds ( Table-2 ) .

Infiltration Number ( If )

Infiltration figure of a drainage basin is the merchandise of drainage denseness and stream frequence of a basin. It is the figure by virtuousness of which an thought sing the infiltration features of the basin is obtained. The higher value indicates low infiltration and high overflow. In the present survey, sub-watershed B-I has the highest value while B-III has the lowest value ( Table-2 ) therefore, bespeaking lowest and highest infiltration, severally.

Form Factor ( Rf )

The signifier factor is the ratio of basin country to square of the basin length and is a quantitative look of drainage basin lineation [ 14 ] . The Rf values ( Table-2 ) in the survey country varies from 0.10 to 0.42, therefore indicate that the sub-watersheds B-II and B-III are about round in form whereas the lower values of signifier factor in the staying sub-watersheds, indicate that they are elongated 1s.

Circularity Ratio ( Rc )

Circularity ratio is the ratio of the basin country to the country of a circle holding the same perimeter margin as the basin, which is dimensionless and expresses the grade of disk shape of the basin [ 17 ] . This besides indicates the inclination of little drainage basin in homogenous geologic stuffs to continue geometrical similarity.

The Rc values, vary between 0.57 and 0.62 ( B-II and B-III ) , indicate that these sub-watersheds are more or less round in form, whereas Rc values 0.45 and 0.20 for sub-watershed B-I and B-IV, severally indicate that these are more or less elongated ( Fig.7 ) and are characterized by moderate to low alleviation and drainage system seems to be partly controlled by the structural perturbations ( Table-2 ) .

Elongation Ratio ( Re )

Elongation ratio is the ratio of diameter of a circle of the same country as the drainage basin and the maximal length of the basin [ 11 ] . A round basin appear to more efficient in the discharge of run-off than that of an extended basin 13. The Re values by and large ranges between 0.6 and 1.0 over a broad assortment of clime and geologic types. Valuess near to 1.0 are the features of the part of really low alleviation, while values in the scope of 0.6 – 0.8 normally occur in the countries of high alleviation and steep land slope10. These values are farther categorized as handbill ( & gt ; 0.9 ) , egg-shaped ( 0.9-0.8 ) and less elongated ( & lt ; 0.7 ) . The Re values in the survey country vary between 0.69 and 0.84 ( Table-2 ) , which indicate centrist to somewhat immerse land incline. The lowest value in instance of B-IV sub-watershed indicate high alleviation and steep incline whereas sub-watersheds B-II and B-III have Re values as 0.73 and 0.72, severally which indicate about apparent land with moderate to low alleviation and low incline.

Length of Overland Flow ( Lg )

Length of overland flow is defined as the length of flow way, projected to the horizontal, non channel flow from point on the drainage divide to a point on the next watercourse channel [ 1 ] . Lg is one of the most of import independent variable impacting both hydrologic and physiographic development of drainage basins and relates in return to the mean incline of the channel and is quiet synonymous with the length of sheet flow to a big extent [ 1 ] . The length of overland flow depends chiefly on the grade of alleviation atomization, and therefore on the drainage denseness. Overland flow is significantly affected by infiltration ( exfiltration ) and infiltration through the dirt, both changing in clip and infinite. The computed value of all four sub-watersheds varies from 0.98 to 2.25. Table- 2 reveals that Lg values for B-IV sub-watershed is less with high drainage denseness when compared with B-I, B-II and B-III sub-watersheds.

Relief Aspects

The alleviation facets determined include relief ratio, comparative alleviation and huskiness figure. The consequences of the analysis are given in Table-2.

Relief Ratio ( Rh )

The alleviation ratio is obtained when basin alleviation “ H ” is divided by the maximal basin length ( Lb ) which consequences in a dimensionless ratio which is equal to the tangent of the angle formed by two planes crossing at the oral cavity of the basin called alleviation ratio which measures the overall abruptness of a drainage basin and is an index of the strength of erosional procedure runing on incline of the basin [ 18 ] . The values of Rh in all the sub-watersheds are given in Table-2 which ranges from 0.00041 ( B-IV ) to 0.00054 ( B-II ) and therefore indicates low alleviation and chair to pacify incline.

Relative Relief ( Rhp )

This term was used by Melton [ 19 ] .The comparative alleviation of different sub-watersheds have been determined and given in Table-2. It is noted that B-III sub-watershed has ( 0.026 ) upper limit value of comparative alleviation and B-IV sub-watershed has the ( 0.016 ) lower limit value. Furthermore, ocular survey of the SRTM DEM ( Fig.2 ) ( indicates that the lift varies from 128m to 167m which represent the land surface has gentle to chair incline.

Ruggedness Number ( HD )

It is the merchandise of maximal basin alleviation ( H ) and drainage denseness ( D ) , where both parametric quantities are in the same unit. An utmost high value of huskiness figure occurs when both variables are big and incline is non merely steep but long every bit good [ 20 ] . In the present survey, the value of ruggedness figure ( Table-2 ) is low which indicates soft incline of all the sub-watersheds.

Decisions

Remote detection and GIS is accepted to be powerful geospatial techniques in fixing the drainage map and understanding the water parting ‘s morphometric parametric quantities. Detailed morphometric survey of all sub-watersheds represents dendritic to sub-dendritic drainage form and a fluctuation in the values of Rb among the sub-watersheds is attributed to the difference in topography and geometric development. The Fs values for all sub-watersheds demonstrate a positive correlativity with the Dd values therefore, bespeaking the addition in the watercourse population with regard to increase in drainage denseness and the values besides indicate permeable sub-soil stuff. In this survey, the drainage denseness, watercourse frequence and drainage strength values is an indicant that the strength of dissection in the country is really low. Low drainage densenesss are frequently associated with widely spaced watercourses due to the presence of less immune stuffs ( petrologies or sway types ) , or those with high infiltration capacities. Shape parametric quantities of the sub-watersheds indicate that the B-I and B-IV sub-watersheds are more or less extended whereas, B-II and B-III are more or less round. Relief facets and ocular reading of DEM of the survey country indicate gentle to chair incline, low run away and high infiltration.