ABSTRACT
The generation of surface runoff is a very complex, dynamic, and non-linear method and is influenced by different correlated factors. Runoff estimation is very important for the development and sustainable management of water resources. There are plenty of methods and models available for runoff estimation, the Soil Conservation Services (SCS) or Natural Resources Conservation Services (NRCS)-Curve Number (CN) method is one of them. The SCS has developed an index called Curve Number to extract the potential runoff from a drainage area or basin. Antecedent moisture condition, soil, and land use/land cover (LULC) are used in combination to determine the curve number of a drainage basin. The hydrological soil group (HSG) is also taken into consideration. There are four types of soils are available in HSG: A, B, C, and D. Soil group A consists of higher rates of infiltration and low runoff, and soil group D has low rates of infiltration and high runoff potential. In the present study, the Sanjai River basin, Jharkhand, was selected as the study area. ArcGIS 10.1 and Erdas14 software were involved to create the thematic layers such as soil map LULC map, etc. The whole watershed was divided into sub-watersheds to calculate the runoff with more precision. From the study, this is clear that the SCS-CN method is very appropriate for runoff estimation. The study reveals that the proper analyzing of surface runoff will guide us to the sustainable use of water in agriculture, industry, and domestic sectors and in this way, the resources can be sustainably controlled.
