ANALYSIS OF THE RUNOFF FOR HOSKOTE SUB-WATERSHED USING SCS-CN METHOD AND GEOGRAPHIC INFORMATION SYSTEMS

Abstract

Reliable estimation of surface runoff is vital for effective watershed management, especially in regions characterized by variable rainfall patterns. This study investigates the Hoskote Sub-Watershed using the Natural Resources Conservation Service- Curve Number (NRCS-CN) method, integrated with Geographic Information Systems (GIS) and Remote Sensing (RS) techniques, to model the rainfall-runoff relationship. Curve Number (CN) values were derived by overlaying land use/land cover data with hydrologic soil group classifications. Historical rainfall data from 1985 to 2015, sourced from the Indian Meteorological Department, along with satellite-derived thematic layers, served as essential inputs. The findings indicate that the average annual runoff in the sub-watershed is approximately 170.08 mm, constituting about 5% of the mean annual rainfall of 837.70 mm. A strong positive correlation (R = 0.85) Mooganayakanakote Veeranna Ramaswamy, Shivkumar J Nyamathi, Navyashree M L, Shruti Halli https://iaeme.com/Home/journal/IJCIET 23 editor@iaeme.com between annual rainfall and runoff was observed, with the highest runoff recorded in 2022. The study demonstrates that the NRCS-CN method, when complemented by GIS and RS technologies, provides a reliable and efficient approach for runoff estimation in ungauged catchments