SCS-Curve Number Based Runoff Estimation for Dharta Watershed, Udaipur, Rajasthan

This study focuses on surface runoff estimation by using the SCS and Curve Number method (SCS-CN) in a catchment of Dharta watershed Udaipur district, Rajasthan. The daily and annual surface runoff was computed for the Sixteen-year period (2001-2016) by using the SCS-CN model. Land use/Land cover (LULC) map of the study catchment was prepared with the help of ArcGIS10.1. The study area consists of a total number of eleven distinct land use/Land cover types, namely Road, Railways, Drainage, Settlements, Kharif crop, Rabi crop, Rabi& Kharif crop, Fallow land, Land with shrubs, and Land without shrubs. It is apparent from the LULC map that agriculture land covers an area of 42.67 km2 encompasses the highest proportion (i. e.67.68 %) in the study area. The hydrological soil group (HSG) of the catchment was assigned based on soil type. The weighted curve number under antecedent moisture condition (AMC) I, II, and III was computed as 57.56, 76.14, 88.00, respectively. The annual runoff ranged from 63.19 mm (17.40 % of rainfall) in the year 2002 to 445.20 mm (45.23 % of rainfall) in the year 2006. Relatively high R2 0.86 values indicated a significant linear relationship between rainfall and runoff.