Prioritization of micro-watershed based on morphometric analysis and runoff studies in upper Darna basin, Maharashtra, India

Abstract

The watershed prioritization based on morphometric analysis and surface runoff has more importance in soil and water conservation and further planning at micro-level. The present study demonstrates the usefulness of GIS for prioritization of the micro-watersheds of the upper Darna River basin of Nashik District of Maharashtra. The aim of the paper is to apply a composite score of morphometric analysis and surface runoff for prioritization of sub-watersheds for identification of soil erosion and high runoff. The study area extends between 19° 36′ N to 19° 48′ N latitudes and 73° 39′ E to 73° 44′ E longitudes which comprise the area of the upper Darna River basin, and it covers around 389.6 km2 area. Arc GIS Software Ver.10.2 and Global Mapper software have been used for morphometric analysis. Rational formula has been employed to find out rainfall intensity, time of concentration and surface runoff. Entire study area is divided into 140 micro-watersheds, named DARN_A for first-, DARN_B for second-, DARN_C for third-, DARN_D for forth- and DARN_E for fifth-order streams. The finding shows that among 140 micro-watersheds, 19 micro-watersheds consist of 278.17 km2 area of the total study area, which represents 78.75% areas that are depicted in high soil erosion and excessive runoff. Therefore, these 19 micro-watersheds required immediate attention to provide soil conservation measures.