Surface Runoff Estimation for Godavari Eastern Delta Using SCS Curve Number and Geographical Information System

NRSC-CN for surface runoff estimation is one of the most widely used methods. GIS and remote sensing techniques facilitate accurate estimation of surface runoff from an area. Water availability estimation can be understand by rainfall and runoff is essential. Runoff generated by rainfall 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 estimate runoff in a study area. The study was carried out in Godavari Eastern Delta in Andhra Pradesh, India. The land use/land cover map, soil map was prepared. The soil and land use map has been prepared by the information available at Andhra Pradesh space application centre. For the rectification of reference, soil and land use map of the study area ERDAS IMAGINE-8.4 software was used. For 30 years surface runoff was estimated, as the runoff value depends on the rainfall, trend of runoff was found to be highly dependable on the quantity of rainfall received within the entire study area. The yearly trend of rainfall during 1987 was 8.97 it’s but the other years, and therefore the runoff was also found to follow an equivalent trend. Similarly, for the year 1995, the runoff was recorded as high, which was also having the highest rainfall.