Morphometric Analysis of Patapur Micro-watershed in North-Eastern Dry Zone of Karnataka Using Geographical Information System: A Case Study

Abstract

The application of remote sensing and geographical information system for the analysis of morphometric parameters are found to be of immense utility in watershed prioritization for soil, water conservation and natural resources management at micro level. Geomorphological analysis is the systematic description of watershed geometry and its stream system. These parameters directly or indirectly reflect the response of entire watershed based on causative factors that are affecting runoff and sediment loss. To prepare a watershed development plan, morphometric analysis have been studied in the Patapur micro-watershed (488.75 ha), being located at Raichur district of Karnataka. The boundary of the watershed was digitized from the SOI (Survey of India) toposheet and also DEM and slope maps were prepared with the help GIS techniques (QGIS). The morphometric parameters such as linear, aerial and relief aspects have been determined to understand the watershed characteristics. In the Patapur micro-watershed the bifurcation ratio (Rb) was varied from 1.75 to 4.0 with average of 2.88 which indicates that on undistorted geologic structure and drainage system of moderate peaks and lower order streams. The values of form factor (Rf), shape factor (Sb), circulatory ratio (Rc) and elongation ratios (Re) were 0.329, 2.28, 0.512 and0.647 respectively which indicates moderately elongated micro-watershed with leading moderate influence on time parameters. The estimated values of relief, relief ratio (Rr) and relative relief (RR) were found to be 114 m, 0.130 and 0.05 respectively, these indicates the possibly moderate erosion. Over all study suggests that the watershed should be treated with soil and water conservation measures