TY - JOUR
T1 - Litho-structural control on interbasin groundwater transfer in central Ethiopia
AU - Azagegn, Tilahun
AU - Asrat, Asfawossen
AU - Ayenew, Tenalem
AU - Kebede, Seifu
N1 - Funding Information:
The German Academic Exchange Service (DAAD) is highly acknowledged for a Ph.D. research grant through its office at the Embassy of Germany in Ethiopia. The authors thank the Addis Ababa Water and Sewerage Authority for provision of borehole drilling and pumping test data and for field travel logistic support during data collection. The School of Earth Sciences, Addis Ababa University partly provided field vehicle and other field logistics. This work would not have been completed without the drilling companies and government water works design and supervision enterprises that provided us with water well drilling and pumping test data. The Ministry of Water Resources and the National Meteorological Services Agency are acknowledged for provision of river discharge and meteorological data, respectively. Two anonymous reviewers are acknowledged for their valuable comments, which help improve the original manuscript. This paper is part of the first author’s PhD. research.
Publisher Copyright:
© 2014 Elsevier Ltd.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - In central Ethiopia, litho-structural setup of the three sub-basins of the southern flank of the Middle Blue Nile basin (Guder, Muger and Jema) and the adjacent Upper Awash River basin have been investigated to develop conceptual groundwater flow model and to characterize the groundwater hydrodynamic relationship between the aquifer systems of the two basins. The development of conceptual groundwater flow model is based on interpretation of Digital Elevation Model (DEM) from SRTM and Landsat images together with field geological observation, integrated with existing boreholes lithologic logs and pumping test data. The litho-structural framework, reconstructed from regional stratigraphy and analysis of major regional fault systems, controls the size of recharge area for aquifer systems and aquifer distributions in the groundwater sub-basins. The study has indicated the distinctive geometric setting of the litho-strata of aquifers and aquicludes. The NW-SE trending horsts beneath the volcanic successions and the overlying volcanic ridges control aquifer distribution in the Guder, Muger and Jema groundwater sub-basins, while the E-W trending horsts control aquifer distribution between the Middle Blue Nile and the Upper Awash Rivers basins. Impermeable mudstone constitutes the upper part of the E-W oriented horst at the center of the Muger River sub-basin. This mudstone capped horst underlying the volcanic aquifers is a groundwater divide channeling recharged water in the Blue Nile basin partly towards the Upper Awash basin. Significant proportion of groundwater recharged in the Middle Blue Nile basin (Muger and Jema River sub-basins) contributes to the storage of the aquifer systems of the Upper Awash basin.
AB - In central Ethiopia, litho-structural setup of the three sub-basins of the southern flank of the Middle Blue Nile basin (Guder, Muger and Jema) and the adjacent Upper Awash River basin have been investigated to develop conceptual groundwater flow model and to characterize the groundwater hydrodynamic relationship between the aquifer systems of the two basins. The development of conceptual groundwater flow model is based on interpretation of Digital Elevation Model (DEM) from SRTM and Landsat images together with field geological observation, integrated with existing boreholes lithologic logs and pumping test data. The litho-structural framework, reconstructed from regional stratigraphy and analysis of major regional fault systems, controls the size of recharge area for aquifer systems and aquifer distributions in the groundwater sub-basins. The study has indicated the distinctive geometric setting of the litho-strata of aquifers and aquicludes. The NW-SE trending horsts beneath the volcanic successions and the overlying volcanic ridges control aquifer distribution in the Guder, Muger and Jema groundwater sub-basins, while the E-W trending horsts control aquifer distribution between the Middle Blue Nile and the Upper Awash Rivers basins. Impermeable mudstone constitutes the upper part of the E-W oriented horst at the center of the Muger River sub-basin. This mudstone capped horst underlying the volcanic aquifers is a groundwater divide channeling recharged water in the Blue Nile basin partly towards the Upper Awash basin. Significant proportion of groundwater recharged in the Middle Blue Nile basin (Muger and Jema River sub-basins) contributes to the storage of the aquifer systems of the Upper Awash basin.
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U2 - 10.1016/j.jafrearsci.2014.10.008
DO - 10.1016/j.jafrearsci.2014.10.008
M3 - Article
AN - SCOPUS:84919742559
VL - 101
SP - 383
EP - 395
JO - Journal of African Earth Sciences
JF - Journal of African Earth Sciences
SN - 1464-343X
ER -