Investigating the effect of watershed management on land use, groundwater recharge, and irrigation potential in Tigray region, northern Ethiopia

This study was conducted to investigate the effect of watershed management on groundwater recharge and irrigation expansion in northern Ethiopia.The GIS-based water and energy transfer between soil, plants, and atmosphere under the quasi-steady state (WetSpass) hydrological model was implemented.Two scenarios, before watershed management (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007) and after watershed management (2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018), were investigated.After watershed management, groundwater recharge increased from 9.7, 44.4, and 54.15 mm for dry, rainy, and annual conditions, respectively, to 9.9, 96.2, and 106.13 mm for these conditions.The relationship between calculated and observed groundwater depths results in a coefficient of determination of 0.81.After watershed management, the water balance system had evapotranspiration, surface runoff, and groundwater recharge of 83.7%, 3.0%, and 13.3%, respectively, of total precipitation.Excess groundwater recharge of 6.51% resulted in extending the irrigation area by 12.7 hectares.Results show that WetSpass is effective in estimating groundwater recharge and irrigation area expansion.