Quantitative Analysis of Catchment Using Remote Sensing and Geographic Information System

Watershed management is the process of formulating and carrying out a course of action involving manipulation of natural system of a watershed to achieve specified objectives. This implies the proper use of land and water resources of watershed for optimum production with minimum hazard to natural resources. Remote sensing and GIS techniques have emerged as powerful tools for watershed management programmes. The study area, Harangi Catchment geographically lies between 75(0) 38' E and 75(0) 55' E longitude and 12(0) 24' N and 12(0) 40' N latitude with an area of 417.54 sq km. In the present study an attempt was made to understand the hydrological processes of the catchment at watershed level by deriving the watershed parameters through Remote Sensing, GIS and other data. Based on the drainage pattern and topography, thirteen watersheds were delineated to understand the hydrological process of the catchment at the watershed level. The drainage density of the watersheds varies from 1.36 to 3.42 km/km(2) which indicate that the area is coarse texture. Runoff was estimated using USDA Soil Conservation Services (SCS) Curve Number model. The information such as land use/land cover and hydrological soil group map derived from remotely sensed data were overlayed through ArcGIS software to assign the curve number on polygon wise. Soil erosion was estimated by using Universal Soil Loss Equation (USLE). The weighted soil erosion estimated for the catchment was 19 t/ha/year, which is a moderate soil loss and needs conservation measures. (C) 2015 Published by Elsevier B.V.