Estimating Runoff for Bamnidhi Watershed Using SCS Curve Number Approach and Geospatial Technique

Water is one of the most valuable natural resources and a vital component of the socioeconomic development of a nation. Water resources in India and throughout the world are under a lot of stress as a result of the limited supply and rising demand. Water availability of a region can be better estimated using rainfall runoff relationship. Runoff is mostly produced as a result of rainfall, which is a significant part of the hydrologic cycle. In this study, the rainfall-runoff relation of the Bamnidhi watershed in Chhattisgarh (India) is studied using SCS CN method. Various inputs such as HSG map and land use land cover were overlaid in ArcGIS platform for estimation of weighted curve number, based on which the runoff is estimated. The results of the study indicate that CN values range from 30 to 97. The lowest runoff potential is observed for forest regions having CN value of around 30, while highest runoff potential is observed for water bodies. The total runoff is found to be around 3.6 Million m3 for the period 2011 to 2020, which is about 10 to 25 percent of the total rainfall.