Assessment of Surface Runoff for Nandani River Basin using SCS-CN Method and GIS

Watershed is simply the geographic area through which water flows across the land and drains into a common body of water, whether a stream, river, lake, or ocean. A surface runoff (also known as overland flow) part of watershed is the flow of water occurring on the ground. Soil conservation Service (SCS) method is a simple, widely used efficient method for determining the approximant amount of runoff from a rainfall even in particular area. The runoff estimated from the SCS-CN model used to know the variation of runoff with different land use/land cover and with different soil conditions. The study area is carried out in Nandani river which is a major tributary of Yerala river, Nandani river Kadegaon Tahsil of Sangli District. The yearly rainfall data of 3 rain gauge stations (1998-2019) is collected. Landuse/Landcover map was prepared from the satellite image and soil map of study area was prepared using GIS. Landuse/Landcover map and Soil map are used to estimate curve number for SCS method. Antecedent Moisture Conditions (AMC-I, AMC-II and AMC-III) are also used for selecting suitable curve number in study area. SCS-CN method was used to determine the runoff depth distribution using Remote sensing and GIS.