TR(BR)-125 : Runoff modelling using SCS method

Abstract

SCS curve number technique is used to obtain runoff volume from landuse/ cover, soil and rainfall data. The technique is applied to Temur catchment of Narmada basin. The catchment lies between latitudes 22°35'N to 23°02'N and longitudes 79°40'E to 79°58'E. The area of catchment upto gauge discharge site is approximately 813 sq. km. The landuse/ cover and soil maps are derived from visual interpretation of IRS LISS II FCC paper prints. The landuse/ cover map is verified from Survey of India topographic maps. Land treatment, crop type in agricultural area and hydrological conditions of forest are assumed. From daily rainfall data, rainfall maps are obtained using moving average interpolation technique. Thrice daily. Discharges are obtained from gauge discharge relationship. The base flow separation is done using technique for complex storms. The volume of base flow and total runoff are used to compute direct runoff volume. The curve numbers are derived from various hydrological conditions and crop types. landuse cover map and soil map. Error varies from -8.6 to 26.5 96- in modified method and from 3. 7 to 37.1 k in original method.