Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia
Study region: Robit-Bata watershed, Upper Blue Nile basin, Ethiopia. Study focus: Stable isotopes of water (Oxygen-18 and Deuterium) were used as tracers to estimate the contribution of groundwater in shallow hillslope aquifers to streamflow in the Robit-Bata watershed. To assess the spatiotemporal...
| Main Authors: | , , , , , , , , , |
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| Format: | Journal Article |
| Language: | Inglés |
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Elsevier
2021
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10568/115164 |
| _version_ | 1855530965143650304 |
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| author | Setargie, T. A. Tilahun, Seifu A. Schmitter, Petra S. Moges, M. A. Gurmessa, S.K. Tsunekawa, A. Tsubo, M. Berihun, Mulatu L. Fenta, A. A. Haregeweyn, Nigussie |
| author_browse | Berihun, Mulatu L. Fenta, A. A. Gurmessa, S.K. Haregeweyn, Nigussie Moges, M. A. Schmitter, Petra S. Setargie, T. A. Tilahun, Seifu A. Tsubo, M. Tsunekawa, A. |
| author_facet | Setargie, T. A. Tilahun, Seifu A. Schmitter, Petra S. Moges, M. A. Gurmessa, S.K. Tsunekawa, A. Tsubo, M. Berihun, Mulatu L. Fenta, A. A. Haregeweyn, Nigussie |
| author_sort | Setargie, T. A. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Study region: Robit-Bata watershed, Upper Blue Nile basin, Ethiopia.
Study focus: Stable isotopes of water (Oxygen-18 and Deuterium) were used as tracers to estimate the contribution of groundwater in shallow hillslope aquifers to streamflow in the Robit-Bata watershed. To assess the spatiotemporal variability of shallow groundwater and develop a hydrograph separation technique, we collected rainfall, shallow groundwater, and streamflow samples and analyzed their d18O and d2 H isotopic compositions. The local meteoric water line (LMWL) and local evaporative line (LEL) of the study area were determined and compared with the global meteoric water line (GMWL). A standard unweighted two-component isotope-based hydrograph separation model was used to determine the percentage contribution of shallow groundwater to streamflow.
New hydrological insights for the region: The LMWL (d2 H = 8.63·d18O + 18.2) mostly showed heavy isotopic enrichment relative to GMWL, and the LEL (d2 H = 5.45·d18O + 6.96) indicated isotopic enrichment compared to Ethiopian lakes. Shallow groundwater responded rapidly to rainfall, with good spatial correlation depending on topographic positions of wells. Pre-event water contributed 90% when the watershed reached maximum storage. This finding gives insight towards the predominant runoff generation process and has significant implications for sustainable dry season irrigation expansion in the area as the sub-surface flow drains out of the watershed from October onwards reducing water tables in the shallow wells. |
| format | Journal Article |
| id | CGSpace115164 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | Elsevier |
| publisherStr | Elsevier |
| record_format | dspace |
| spelling | CGSpace1151642025-10-14T15:09:09Z Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia Setargie, T. A. Tilahun, Seifu A. Schmitter, Petra S. Moges, M. A. Gurmessa, S.K. Tsunekawa, A. Tsubo, M. Berihun, Mulatu L. Fenta, A. A. Haregeweyn, Nigussie groundwater watersheds shallow wells rain stream flow aquifers runoff dry season irrigation hydrographs stable isotopes case studies Study region: Robit-Bata watershed, Upper Blue Nile basin, Ethiopia. Study focus: Stable isotopes of water (Oxygen-18 and Deuterium) were used as tracers to estimate the contribution of groundwater in shallow hillslope aquifers to streamflow in the Robit-Bata watershed. To assess the spatiotemporal variability of shallow groundwater and develop a hydrograph separation technique, we collected rainfall, shallow groundwater, and streamflow samples and analyzed their d18O and d2 H isotopic compositions. The local meteoric water line (LMWL) and local evaporative line (LEL) of the study area were determined and compared with the global meteoric water line (GMWL). A standard unweighted two-component isotope-based hydrograph separation model was used to determine the percentage contribution of shallow groundwater to streamflow. New hydrological insights for the region: The LMWL (d2 H = 8.63·d18O + 18.2) mostly showed heavy isotopic enrichment relative to GMWL, and the LEL (d2 H = 5.45·d18O + 6.96) indicated isotopic enrichment compared to Ethiopian lakes. Shallow groundwater responded rapidly to rainfall, with good spatial correlation depending on topographic positions of wells. Pre-event water contributed 90% when the watershed reached maximum storage. This finding gives insight towards the predominant runoff generation process and has significant implications for sustainable dry season irrigation expansion in the area as the sub-surface flow drains out of the watershed from October onwards reducing water tables in the shallow wells. 2021-10 2021-09-26T16:12:25Z 2021-09-26T16:12:25Z Journal Article https://hdl.handle.net/10568/115164 en Open Access Elsevier Setargie, T. A.; Tilahun, S. A.; Schmitter, Petra; Moges, M. A.; Gurmessa, S. K.; Tsunekawa, A.; Tsubo, M.; Berihun, M. L.; Fenta, A. A.; Haregeweyn, N. 2021. Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia. Journal of Hydrology: Regional Studies, 37:100901. [doi: https://doi.org/10.1016/j.ejrh.2021.100901] |
| spellingShingle | groundwater watersheds shallow wells rain stream flow aquifers runoff dry season irrigation hydrographs stable isotopes case studies Setargie, T. A. Tilahun, Seifu A. Schmitter, Petra S. Moges, M. A. Gurmessa, S.K. Tsunekawa, A. Tsubo, M. Berihun, Mulatu L. Fenta, A. A. Haregeweyn, Nigussie Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia |
| title | Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia |
| title_full | Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia |
| title_fullStr | Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia |
| title_full_unstemmed | Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia |
| title_short | Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: a case study in the Upper Blue Nile Basin, Ethiopia |
| title_sort | characterizing shallow groundwater in hillslope aquifers using isotopic signatures a case study in the upper blue nile basin ethiopia |
| topic | groundwater watersheds shallow wells rain stream flow aquifers runoff dry season irrigation hydrographs stable isotopes case studies |
| url | https://hdl.handle.net/10568/115164 |
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