Land use and land cover changes in Kulfo River watershed experience enormously of human instabilities due to agricultural development, and growing urban demand for charcoal, cutting wood for energy; resulting in forest and land degradation. This consecutively transformed the hydrologic responses of the watershed. The purpose of this study was assessing the hydrological impact of land use change on Kulfo River watershed. Distributed hydrologic modeling is used to characterize watershed dynamics where as various spatial parameters could be secondhand and runoff simulated at required scale. Spatial data (i.e. DEM, land use, soil), hydro-meteorological data were obtained from Ministries of Water Resources and Irrigation, National Meteorology agency, applied to explain the associated the simulate stream-flow and impact of land use/cover change for the year of 1985, 1995 and 2005. Land use maps of 1985, 1995 and 2005 extracted from satellite images performed using ERDAS Imagine 9.1 software, used for further analysis of SWAT model run. Land cover change analysis increases in the proportion of the Agricultural land from 11.9% to 14.39%, Bare land 25.8% to 14.14%, Forest 16% to 12.43%. Water body remain stable, however, Shrub land increased from 29.28% to 36.82%in between 1985 to 2005. Sensitivity analysis has shown that the curve number is the most sensitive parameter of the watershed. The models were calibrated using flow data from the 1989 to 2001 and validated from 2002 to 2008. The R2 and Nash- Sutcliffe Efficient (NSE) value were 0.78 and 0.93 for the calibration and validation 0.80 and 0.78 respectively. It has been concluded that hydrological impact of Land Use change highly affected the increase of surface runoff and low infiltrations rate in the watershed.
Keywords: Land Use Change, SWAT Model, ERDAS Imagine, Kulfo River Watershed