Estimation of Runoff Depth and Volume Using NRCS-CN Method in Konar Catchment (Jharkhand, India)

Abstract

Accurate estimation of runoff depth and volume is an important task for proper watershed management. Rainfall generated runoff is not only dependent on the intensity, duration and the distribution of rainfall, but also soil type, vegetation, and land use types have significant effects on the runoff pattern. The present study aims to determine the runoff depth and volume using Natural Resource Conservation Service Curve Number (NRCS-CN) method. The study was carried out in Konar catchment located in Jharkhand, India. The land use/land cover map, soil map were prepared in GIS environment. The NRCS- curve number method was followed to estimate the runoff depth for selected rainfall events in the catchment. The result showed that the average volume of surface runoff from 2000 to 2009 for Konar catchment was 71510.76 m3 which represents only 6.3% of the annual average rainfall. Statistically positive correlation (R2=0.53) have found between rainfall and runoff depth. The present study reveals that NRCS-CN method with integration of GIS and remote sensing technology can effectively be used to estimate the runoff in an ungauged river catchment with similar hydrological characteristics.