EFFECT OF LAND USE CHANGE ON SURFACE RUNOFF IN AN UNGAUGED BASIN IN WESTERN HIMALAYA, INDIA

ABSTRACT: Land use land cover (LULC) is an important component that plays a significant role in conversion of precipitation into various hydrologic components. LULC change has created water related dilemma, globally, by altering hydrologic processes. Hence, quantitative assessment of hydrologic response is essential for planning and strategy development. Hydrologic modelling is most suitable to assess the relative impact of each LULC class on hydrologic response, even in ungauged basin. This study is focused to estimate the changes in surface runoff in an ungauged river basin in western Himalaya that has been experiencing rapid industrialization since last two decades. Using Soil and Water Assessment Tool (SWAT), surface runoff is estimated for the periods of 1984 – 2008 using two LULC of 1989 and 2009, respectively. After satisfactory calibration of the SWAT model with MODIS evapotranspiration data, the change in surface runoff is estimated for two LULC maps using same climate data. The simulation result showed that LULC change has increased surface runoff by 12 % from 1989 to 2009. The expansion of cropland (by 9.84%) and built-up area (by 6.54%) has increased surface runoff by 12.97 % and 17.21%, respectively during the same period. This practicable and simple approach could widely be applied to a variety of ungauged basins. 1