HYDROLOGICAL MODELLING OF SABARMATI RIVER USING SWAT

Abstract

Water resources of India have experienced wide array of changes over time. Extreme hydrological events call for adequate management measures to be taken up. The management of water resources taken up as a whole is an enormous task in itself. A watershed is considered as a unitary land unit in the development of a sustainable ecosystem. So watershed modelling has become the need of the hour. With the ever increasing pressure of population, rapid urbanization and climate changes coupled with poor management of land and water resources, the natural hydrological processes in the watershed gets altered so there is an imperative need to conduct the use of an apt and adequate modelling tool. In this dissertation it is envisaged to undertake hydrological modelling in the Sabarmati River basin using the Soil and Water Analysis Tool (SWAT). The ArcGIS interface for the SWAT model, ArcSWAT allows the use of Geographical Information System (GIS) inputs like the Digital Elevation Model (DEM), land use maps and soil maps for the extraction and zoning of the watershed. The entire watershed was divided into 37 subbasins and 213 HRUs. The model was simulated for a period of six years with one year as a warm-up period which resulted in the simulated results. Simulation with the calibrated model with climate data for the years 2001-2005 showed an accurate and satisfying result with the coefficient of determination R2 as 0.7629 for discharge prediction and 0.7515 for rainfall-runoff prediction from the water budget equation. The calibrated model can be used for further analysis for management of water resource and climate and land use change impact studies.