Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, Ethiopia
Alluvial rivers adjust their geometry in response to environmental and anthropogenic disturbances. Flow regulation results in a new geomorphic condition that affects the aquatic ecosystem and its nature. This paper examines the long-term effects of flow regulation on the geomorphic and ecological re...
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| Format: | Article |
| Language: | English |
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Elsevier
2024-11-01
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| Series: | Heliyon |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405844024162548 |
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| author | Chalachew A. Mulatu Goraw Goshu Yemer Wubneh Belete Abebe Yonas Amsalu |
| author_facet | Chalachew A. Mulatu Goraw Goshu Yemer Wubneh Belete Abebe Yonas Amsalu |
| author_sort | Chalachew A. Mulatu |
| collection | DOAJ |
| description | Alluvial rivers adjust their geometry in response to environmental and anthropogenic disturbances. Flow regulation results in a new geomorphic condition that affects the aquatic ecosystem and its nature. This paper examines the long-term effects of flow regulation on the geomorphic and ecological responses of the downstream river channels of the Abay River, which is the only natural outflow of Lake Tana, Ethiopia. Since 1996, the river's discharge regime has been affected by constructing a head-rise weir (Chara Chara) at its natural outlet for hydropower production and dam construction on the Lake Tana tributary rivers. Hydrologic data collected at the outlet of the river, SPOT, and Google Earth images were used for the study. River banks and bed topography were extracted via ArcGIS for selected study periods. The study revealed that existing water resource development on the tributary rivers of Lake Tana modified (decreased) the outflow discharge on the Abay River, and resulted a changed morphological and moderate level ecological impact on the river system. Future ongoing and planned water resource developments will exacerbate the pressure on the lake. Without careful management, these changes are likely to have severe morphological, ecological and social consequences. |
| format | Article |
| id | doaj-art-cc481de0b39948469fc1d81bf7aaef21 |
| institution | OA Journals |
| issn | 2405-8440 |
| language | English |
| publishDate | 2024-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Heliyon |
| spelling | doaj-art-cc481de0b39948469fc1d81bf7aaef212025-08-20T02:07:34ZengElsevierHeliyon2405-84402024-11-011022e4022310.1016/j.heliyon.2024.e40223Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, EthiopiaChalachew A. Mulatu0Goraw Goshu Yemer1Wubneh Belete Abebe2Yonas Amsalu3Faculty of Civil and Water Resources Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia; Blue Nile Water Institute, Bahir Dar University, Bahir Dar, Ethiopia; Corresponding author. Faculty of Civil and Water Resources Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia.Blue Nile Water Institute, Bahir Dar University, Bahir Dar, Ethiopia; College of Agriculture and Environmental Sciences, Bahir Dar University, Bahir Dar, EthiopiaBlue Nile Water Institute, Bahir Dar University, Bahir Dar, EthiopiaFaculty of Civil and Water Resources Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, EthiopiaAlluvial rivers adjust their geometry in response to environmental and anthropogenic disturbances. Flow regulation results in a new geomorphic condition that affects the aquatic ecosystem and its nature. This paper examines the long-term effects of flow regulation on the geomorphic and ecological responses of the downstream river channels of the Abay River, which is the only natural outflow of Lake Tana, Ethiopia. Since 1996, the river's discharge regime has been affected by constructing a head-rise weir (Chara Chara) at its natural outlet for hydropower production and dam construction on the Lake Tana tributary rivers. Hydrologic data collected at the outlet of the river, SPOT, and Google Earth images were used for the study. River banks and bed topography were extracted via ArcGIS for selected study periods. The study revealed that existing water resource development on the tributary rivers of Lake Tana modified (decreased) the outflow discharge on the Abay River, and resulted a changed morphological and moderate level ecological impact on the river system. Future ongoing and planned water resource developments will exacerbate the pressure on the lake. Without careful management, these changes are likely to have severe morphological, ecological and social consequences.http://www.sciencedirect.com/science/article/pii/S2405844024162548Abay RiverBlue Nile BasinEcohydrologyFlow regulationGeomorphologyLake Tana |
| spellingShingle | Chalachew A. Mulatu Goraw Goshu Yemer Wubneh Belete Abebe Yonas Amsalu Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, Ethiopia Heliyon Abay River Blue Nile Basin Ecohydrology Flow regulation Geomorphology Lake Tana |
| title | Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, Ethiopia |
| title_full | Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, Ethiopia |
| title_fullStr | Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, Ethiopia |
| title_full_unstemmed | Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, Ethiopia |
| title_short | Long-term effects of Abay River flow regulation at Lake Tana on the geomorphic and ecological responses of the downstream river channels, Upper Blue Nile basin, Ethiopia |
| title_sort | long term effects of abay river flow regulation at lake tana on the geomorphic and ecological responses of the downstream river channels upper blue nile basin ethiopia |
| topic | Abay River Blue Nile Basin Ecohydrology Flow regulation Geomorphology Lake Tana |
| url | http://www.sciencedirect.com/science/article/pii/S2405844024162548 |
| work_keys_str_mv | AT chalachewamulatu longtermeffectsofabayriverflowregulationatlaketanaonthegeomorphicandecologicalresponsesofthedownstreamriverchannelsupperbluenilebasinethiopia AT gorawgoshuyemer longtermeffectsofabayriverflowregulationatlaketanaonthegeomorphicandecologicalresponsesofthedownstreamriverchannelsupperbluenilebasinethiopia AT wubnehbeleteabebe longtermeffectsofabayriverflowregulationatlaketanaonthegeomorphicandecologicalresponsesofthedownstreamriverchannelsupperbluenilebasinethiopia AT yonasamsalu longtermeffectsofabayriverflowregulationatlaketanaonthegeomorphicandecologicalresponsesofthedownstreamriverchannelsupperbluenilebasinethiopia |