Impact of land use and land cover change on the magnitude of surface runoff in the endorheic Hayk Lake basin, Ethiopia

This study focused to analyze the main human-induced land use and/or cover changes and their impact on the response to surface runoff from the Hayk Lake endorheic basin between 1989 and 2015. The investigation of Landsat images of years 1989, 2000 and 2015 with the aid of ArcGIS 10.1 indicated an increase in cultivation land by 137.74% at the disbursement of a decrease of 1.34% in lake water, 49.48% in shrubland, 55.84% in plantation, and 17.32% in grassland. Overall accuracy (92%–96%) and kappa values (0.90–0.95) proved that the image classifications were accurate. The impact of the changed land use and/or cover on surface runoff was investigated by simulating the surface runoff for the years 1989, 2000 and 2015, and then quantifying the individual rate of contribution of land use and/or cover change on the magnitude of simulated surface runoff using HEC-HMS modeling tool. The analysis found that land use and cover change alone increased surface runoff by 20.18% and that climate change reduced surface runoff by 120.18%. The combined effect reduced surface runoff and caused a continued decline in water level at Hayk Lake. Therefore, this study advocated basin-based lake water management strategies linked to the negative impacts of land use and land cover, and climate change on the water balance of Hayk Lake for its sustainability.