Estimation of runoff potential using curve number method

Runoff estimation is important for hydrological structure design. The SCS curve number (SCS-CN) approach is a popular technique for assessing rainfall-induced direct runoff. In this study, the runoff depth was calculated for the Hebburu micro-watershed in Tarikere Taluk, Chikkamagaluru district, Karnataka, using the Soil Conservation Service-Curve Number (SCS-CN) method. The Hebbur Micro-Watershed, which spans an area of 1038 ha, is situated between latitudes of 13° 46’ 14.81” N to 13° 44’ 23.95” N and longitudes of 75° 58’ 24.38” E to 76° 0’ 41.14” E. For the analysis, many parameters including information on the soil, rainfall, and land use were taken into account. Daily runoff was estimated between 2009–2018. Highest runoff was observed during 2014 (520 mm) followed by 2010 and 2009. During 2016 lowest runoff was generated in the watershed due to low rainfall in the year. Correlation coefficient between rainfall and runoff was found 97 per cent between 2009–2018. The results showed that the curve number approach, when combined with remote sensing and GIS technologies, can be effectively be used to estimate the runoff in an ungauged watershed.