DERIVATION OF GEOMORPHOLOGICAL UNIT HYDROGRAPH FROM CATCHMENT BASED GEOMORPHOLOGICAL CHARACTERISTICS USING REMOTE SENSING AND GIS

Abstract

Geomorphological characteristics of river basin in mountainous areas affect runoff process and formation of
flood in these areas. Since, most of the locations in mountainous areas are either ungauged or sufficient data are not
available for them; the use of remote sensing and GIS techniques is very important. Studies of geomorphological
characteristics of such areas become much more important and significant as the geomorphological characteristics can
be useful in understanding the runoff process for the catchment. In this study, the geomorphological characteristics of
Devak basin such as Bifurcation Ratio, Length Ratio and Area Ratio are determined using Nash model, for which the
values are 4.263, 3.720 and 4.997 respectively, which can be useful in finding out the runoff response for the catchment.
Also, results obtained from the present study are compared with results obtained from toposheets, variation in length
ratio 3.720 as per DEM and 2.030 as per toposheets is observed. This variation is high comparing to the variation for
Bifurcation Ratio which is 4.263 as per DEM and 4.870 as per toposheets, and Area Ratio 4.997 as per DEM and 5.634
as per toposheets.