A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management

Thesis (M.Eng.) - Asian Institute of Technology, 2010

Water resource management and land use management are two of the major issue in socio economical development of any watershed. Changes in water hydrology associated with land use transformation have been considered as a major challenge both in basin as well as national level, especially for a monsoon rainfall fed basin such as Indrawati. In this study land use change model CLUE-S was used with a hydrological model SWAT to evaluate the distinct change in hydrology under various possible future land use changes. Regression analysis between land use and driving factors indicated the possibility of agriculture occurrence is high in the region of high population density, low slope area, at low altitude and the possibility decreases with increase in distance from river and settlement area. Using the regression based relationships, CLUE-S model generated number of possible future land use scenarios in the form of spatially distributed land use map which were used in a SWAT hydrological model to analyze the impact on the hydrology of the basin. Hydrological model simulation for land use change with the forest depleting scenarios resulted in an increase in surface flow and water yield and a decrease in base flow and ET. On the other hand forest area conservation and increase in agriculture resulted in decrease in surface flow and water yield and increase in base flow and ET. In term of seasonal analysis the results showed similar trend except for water yield during winter and autumn which showed a decreasing trend with decreasing forest where as for forest protection scenario an increasing trend was found. The results from this study indicated with the depletion of forest flooding in wet season will increase and water scarcity during dry season could intensify.