“Geo Morphometric Analysis using Remote Sensing and GIS Techniques in a Fluvial System: A case study on Udyavara River Basin South West Coast of India”

Abstract

Udyavara river basin is a tropical coastal river basin with Arabian Sea to west. Western Ghats to the East and couple of Inselbergs to the Central and East. The location of the basin, it’s diverse Physiography from the flat coastal plain, with intervening inselbergs, lateritic plateaus and mounds with river system originating from Western Ghats.   An analysis of slope, Drainage frequency, Drainage Density has been carried out for Udyavara River basin. Result shows a variation from North East to the South West coast tracts. Morphometric and 3^rd order river basin shows high correlation value between stream length, stream number, with stream, area and basin perimeter and basin length. High Value of Runoff is around (R=0.93) which is recorded for total stream length and basin length. Drainage Frequency simulates drainage density in spatial distribution. The major part of the basin is occupied by high frequency and high density.  Rainfall- Isohyets map of Udyavara define low rainfall towards coast and high rainfall towards Western Ghats. The river basin is dominated by variety of drainage pattern including Dendritic, Ridge Pattern, Braided Pattern, Ridge Pattern, Radial, Sub parallel etc., spatial distribution of slop depicts a slope value > 2⁰ towards the west of the study area. This terrain is a linear band, parallel to the coast. Low Slope values have been recorded towards the south coast and relatively high towards south eastern part of the basin. This enhance slope value is due to the presence of the Inselbergs. (121m). In general, the terrain depicts low slope values, unlike terrains that have the Western Ghats where slope of >30⁰ (degree) have been reported (Raghavan B R., 1988)