Regional groundwater flow modeling of the Geba basin, northern Ethiopia

• Published in: Hydrogeology journal Vol. 25; no. 3; pp. 639 - 655
• Main Authors: Gebreyohannes, Tesfamichael, De Smedt, Florimond, Walraevens, Kristine, Gebresilassie, Solomon, Hussien, Abdelwassie, Hagos, Miruts, Amare, Kassa, Deckers, Jozef, Gebrehiwot, Kindeya
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2017; Springer Nature B.V
• Subjects: Agriculture; Aquatic Pollution; Aquifers; Aquitards; Boreholes; Drought; Dug wells; Earth and Environmental Science; Earth Sciences; Exploitation; Geology; Geophysics/Geodesy; Groundwater; Groundwater discharge; Groundwater flow; Groundwater levels; Groundwater resources; Harvesting; Hydrogeology; Hydrology/Water Resources; Irrigation; Modelling; Rain; Rainfall; Rainfed farming; Surface water; Waste Water Technology; Water flow; Water harvesting; Water Management; Water Pollution Control; Water Quality/Water Pollution; Water resources; Ethiopia; Numerical modeling; Groundwater-resources assessment; Groundwater flow; MODFLOW; Ethiopia
• ISSN: 1431-2174; 1435-0157
• DOI: 10.1007/s10040-016-1522-8

The Geba basin is one of the most food-insecure areas of the Tigray regional state in northern Ethiopia due to recurrent drought resulting from erratic distribution of rainfall. Since the beginning of the 1990s, rain-fed agriculture has been supported through small-scale irrigation schemes mainly by surface-water harvesting, but success has been limited. Hence, use of groundwater for irrigation purposes has gained considerable attention. The main purpose of this study is to assess groundwater resources in the Geba basin by means of a MODFLOW modeling approach. The model is calibrated using observed groundwater levels, yielding a clear insight into the groundwater flow systems and reserves. Results show that none of the hydrogeological formations can be considered as aquifers that can be exploited for large-scale groundwater exploitation. However, aquitards can be identified that can support small-scale groundwater abstraction for irrigation needs in regions that are either designated as groundwater discharge areas or where groundwater levels are shallow and can be tapped by hand-dug wells or shallow boreholes.