Soil Erosion Prone Analysis for landform zone classification of Sita nadi watershed, Koppa Taluk, Karnataka – A Geomorphologic and Geo-Informatics Approach

Abstract

Soil erosion is the loss of soil from land surface due to the action of wind, water, ice and gravity, its spatial and temporal distribution depends on the interaction of human and physical factors.  It has to be monitored and assessed in regular interval of time, in this regard, Sita Nadi watershed has been considered for erosion prone analysis by using geomorphological and geo-informatics techniques.  The study area is located in between N 13⁰ 15^¹ and N 13⁰ 30^¹ Latitude and E 75⁰   15¹ to 75⁰ 30^¹ E Longitude, with an aerial extent of 224.81 km². The thematic layers like geomorphology, drainages and contours has been prepared by SOI OSM series toposheet D43P7 on 1:50,000 scale and updated on IRS LISS-III satellite image of year 2009.  The entire watershed has been divided into 4 km² grids by using fishnet tool in ArcGIS, then for each grid drainage frequency, drainage density, relative relief and dissection index values are calculated.  The result indicates, about 11.33%, 10.71%, 29.86%, 34.18% and 13.92% of the area is very high, high, moderate, low and very low prone to soil erosion respectively, which indicates improper management of soil in Sita Nadi watershed. The latest technologies like remote sensing and geo-informatics are helpful in identification, assessment and management of Soil Erosion prone zones for sustainable future.