Runoff Estimation By SCS-Curve Number Method By GIS

Abstract

Runoff estimation has become a vital aspect in various fields of water resources planning
such as flood forecasting, agricultural planning, estimation of reservoir storage, designing of
drainage systems and so on. The present study aims to compute runoff from rainfall data
using Soil Conservation Service Curve Number Method (SCS-CN method). CN method
proved to be a successful method for runoff estimation as this method is largely influenced on
the land use pattern, soil composition, the type of season, climate, area of the watershed,
temperature etc. Geographical Information system (GIS) can be effectively applied in runoff
estimation. In the present study, GIS is incorporated in the preparation of land use of the
study area. A sub basin of the Periyar river basin in the state of Kerala, India, is taken as the
study area. The study reveals that SCS CN method supplemented by the application of GIS
can be effectively applied for runoff estimation and thus to forecast its effects.