SURFACE RUNOFF ESTIMATION OF AMRAVATI RIVER BASIN USING INTEGRATED SCS-CN, RS AND GIS TECHNIQUES

A river basin is a hydrological unit surrounded by natural ridges that allow the runoff to drain in a well-defined drainage pattern of streams flowing within the boundaries of the watersheds due to rainfall. Rainfall and runoff are the substantial hydrologic component in the water resources assessment. Various methods are available to estimate runoff from rainfall; still, the Soil Conservation Service Curve Number (SCS-CN) method remains the most popular and often used method as runoff curve number (CN) is an essential factor of the SCS-CN method and depends upon land use/land cover (LULC), soil type, and antecedent soil moisture (AMC) data. Also, various parameters, such as Hydrological Soil Characteristics (HSG), precipitation (P), Potential Maximum Retention (PMR), and Antecedent Moisture Condition (AMC) are the mandatory inputs to the SCS-CN model. In the results, the daily runoff from the Amravati River basin for an average of 31 years, i.e., 1990 to 2021, has been used. As a result, the average annual surface runoff calculated for the Amravati River basin is 223 mm. The total average volume of runoff is 1.77 X 108 m3/year or 1.77 X 1011 Liters/year or 6.25 thousand Million Cubic Feet (TMC), representing 35.68 % of the total average annual rainfall.