he present study is based on SWAT (Soil and Water Assessment Tool) Model which integrates the GIS information with attribute database to estimate the runoff. Soil and Water Assessment Tool (SWAT) is a physically based distributed parameter model which has been developed to predict runoff, erosion, sediment and nutrient transport from agricultural watersheds under different management practices.This model has been used to simulate the rainfall-runoff process in Kankai Basin of Eastern Nepal.The catchment area of the Kankai basin is 1165 square kilometer.In the model Clark unit hydrograph method of rainfall-runoff transformation, deficit constant loss method, constant monthly base flow method, Muskingum method of flow routing, constant monthly evapotranspiration etc. have been selected. The daily rainfall-runoff data of the year 1986-1989 has been used for calibration purpose.
