Assessing the Effect of Land-Use and Land-Cover Change on Groundwater Recharge in Akaki Catchment, Central Ethiopia.

Abstract

Land-Use and Land-cover (LU/LC) changes are the major factors influencing catchment hydrology. Thus, understanding the impact of LU/LC on recharge is important for management of water resources. The present study area is located in the central Ethiopian highlands of the Main Ethiopian Rift. The main objective of this study was to determine the LU/LC change of Akaki catchment between the year1986−2015 G.C and to evaluate the impact of these changes on recharge. To analyze the changes in area over the time, a satellite image was obtained for the years 1986, 2000 and 2015. The methodology consists three steps. First land-cover (LC) maps of the year 1986, 2000 and 2015 were compiled. Secondly, the relationship between hydro meteorological elements and recharge has investigated. Finally, WetSpass modeling was applied to estimate the seasonal and annual ground water recharge. The model was run for the three different years LC maps keeping the other parameters constant. Hence, the result reflects impact of LULC change on recharge. The simulated results of the model indicates that the mean annual recharge was decreasing from 268.6 mm/y for land‒use(LU) map of 1986 to 264.9 mm/y and 260 mm/y for LU maps of 2000 and 2015, respectively. The Study outputs indicated that recharge in the catchment did not change significantly. However, LULC had remarkable variation in the period between1986 and 2015. This result provides a better understanding of the spreading situation of Akaki catchment which would support decision making process to control the ground water conditions.