Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization
The Lake Tana Basin, comprising the largest natural lake in Ethiopia, is the source and the uppermost part of the Upper Blue Nile Basin. In this review paper, research papers, mainly on the rainfall-runoff modeling and lake water balance, and on the hydrogeology, have been reviewed. The earlier wate...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-05-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/13/11/1469 |
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| author | Alemu Yenehun Mekete Dessie Mulugeta Azeze Fenta Nigate Ashebir Sewale Belay Jan Nyssen Enyew Adgo Ann Van Griensven Marc Van Camp Kristine Walraevens |
| author_facet | Alemu Yenehun Mekete Dessie Mulugeta Azeze Fenta Nigate Ashebir Sewale Belay Jan Nyssen Enyew Adgo Ann Van Griensven Marc Van Camp Kristine Walraevens |
| author_sort | Alemu Yenehun |
| collection | DOAJ |
| description | The Lake Tana Basin, comprising the largest natural lake in Ethiopia, is the source and the uppermost part of the Upper Blue Nile Basin. In this review paper, research papers, mainly on the rainfall-runoff modeling and lake water balance, and on the hydrogeology, have been reviewed. The earlier water balance estimation attempts used simple conceptual and statistical approaches and calculate on a monthly timescale. More recent research has been using advanced semi-physically or physically based distributed hydrological models. Accordingly, mean annual precipitation over the lake was estimated in the range 36.1–53.1%; lake evaporation at 45.3–57.5%; river inflow (all gauged and estimated ungauged) at 43.6–63.9%; and river (lake) water outflow at 0–9.2%. With the few isotope studies, groundwater inflow and outflow are found insignificant. Different studies had estimated groundwater recharge, ranging from 57 mm to 850 mm. The basin has a heterogenous aquifer system consisting of different volcanic rocks and alluvio-lacustrine sediments. Generally, groundwater with low TDS, Ca–Mg–HCO<sub>3</sub> type, isotopically relatively enriched, and high TDS, Na–HCO<sub>3</sub> type, isotopically relatively depleted, water types have been identified. In this paper, major research gaps such as aquifer hydraulic characterization, surface-groundwater interaction, groundwater flow and groundwater balance have been identified. Hence, future research shall focus on the groundwater resources, so that existing surface water studies are updated and future water usage options are explored. |
| first_indexed | 2024-03-10T11:06:49Z |
| format | Article |
| id | doaj.art-dbd86230b0b8432ab1ff0bf48e49d9ad |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T11:06:49Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-dbd86230b0b8432ab1ff0bf48e49d9ad2023-11-21T21:05:48ZengMDPI AGWater2073-44412021-05-011311146910.3390/w13111469Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological CharacterizationAlemu Yenehun0Mekete Dessie1Mulugeta Azeze2Fenta Nigate3Ashebir Sewale Belay4Jan Nyssen5Enyew Adgo6Ann Van Griensven7Marc Van Camp8Kristine Walraevens9School of Earth Sciences, Bahir Dar University, P.O. Box 79, Bahir Dar 6000, EthiopiaFaculty of Civil and Water Resources Engineering, Bahir Dar University, P.O. Box 430, Bahir Dar 6000, EthiopiaFaculty of Civil and Water Resources Engineering, Bahir Dar University, P.O. Box 430, Bahir Dar 6000, EthiopiaSchool of Earth Sciences, Bahir Dar University, P.O. Box 79, Bahir Dar 6000, EthiopiaSchool of Earth Sciences, Bahir Dar University, P.O. Box 79, Bahir Dar 6000, EthiopiaDepartment of Geography, Ghent University, Krijgslaan 281 (S8), B-9000 Ghent, BelgiumDepartment of Natural Resource, Bahir Dar University, P.O. Box 79, Bahir Dar 6000, EthiopiaDepartment of Hydrology and Hydraulic Engineering, Faculty of Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, BelgiumLaboratory for Applied Geology and Hydrogeology, Department of Geology, Ghent University, Krijgslaan 281 (S8), B-9000 Ghent, BelgiumLaboratory for Applied Geology and Hydrogeology, Department of Geology, Ghent University, Krijgslaan 281 (S8), B-9000 Ghent, BelgiumThe Lake Tana Basin, comprising the largest natural lake in Ethiopia, is the source and the uppermost part of the Upper Blue Nile Basin. In this review paper, research papers, mainly on the rainfall-runoff modeling and lake water balance, and on the hydrogeology, have been reviewed. The earlier water balance estimation attempts used simple conceptual and statistical approaches and calculate on a monthly timescale. More recent research has been using advanced semi-physically or physically based distributed hydrological models. Accordingly, mean annual precipitation over the lake was estimated in the range 36.1–53.1%; lake evaporation at 45.3–57.5%; river inflow (all gauged and estimated ungauged) at 43.6–63.9%; and river (lake) water outflow at 0–9.2%. With the few isotope studies, groundwater inflow and outflow are found insignificant. Different studies had estimated groundwater recharge, ranging from 57 mm to 850 mm. The basin has a heterogenous aquifer system consisting of different volcanic rocks and alluvio-lacustrine sediments. Generally, groundwater with low TDS, Ca–Mg–HCO<sub>3</sub> type, isotopically relatively enriched, and high TDS, Na–HCO<sub>3</sub> type, isotopically relatively depleted, water types have been identified. In this paper, major research gaps such as aquifer hydraulic characterization, surface-groundwater interaction, groundwater flow and groundwater balance have been identified. Hence, future research shall focus on the groundwater resources, so that existing surface water studies are updated and future water usage options are explored.https://www.mdpi.com/2073-4441/13/11/1469Lake Tana Basinwater balancehydrogeologyaquiferrechargeresearch gap |
| spellingShingle | Alemu Yenehun Mekete Dessie Mulugeta Azeze Fenta Nigate Ashebir Sewale Belay Jan Nyssen Enyew Adgo Ann Van Griensven Marc Van Camp Kristine Walraevens Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization Water Lake Tana Basin water balance hydrogeology aquifer recharge research gap |
| title | Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization |
| title_full | Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization |
| title_fullStr | Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization |
| title_full_unstemmed | Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization |
| title_short | Water Resources Studies in Headwaters of the Blue Nile Basin: A Review with Emphasis on Lake Water Balance and Hydrogeological Characterization |
| title_sort | water resources studies in headwaters of the blue nile basin a review with emphasis on lake water balance and hydrogeological characterization |
| topic | Lake Tana Basin water balance hydrogeology aquifer recharge research gap |
| url | https://www.mdpi.com/2073-4441/13/11/1469 |
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