Floodplain hydrodynamic modelling of the Lower Volta River in Ghana
The impacts of dam releases from re-operation scenarios of the Akosombo and Kpong hydropower facilities on downstream communities along the Lower Volta River were examined through hydrodynamic modelling using the HEC-RAS hydraulic model. The model was used to simulate surface water elevation along t...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2017-12-01
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| Series: | Journal of Hydrology: Regional Studies |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214581817301635 |
| _version_ | 1819080534366617600 |
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| author | Frederick Yaw Logah Akurugu Barnabas Amisigo Emmanuel Obuobie Kwabena Kankam-Yeboah |
| author_facet | Frederick Yaw Logah Akurugu Barnabas Amisigo Emmanuel Obuobie Kwabena Kankam-Yeboah |
| author_sort | Frederick Yaw Logah |
| collection | DOAJ |
| description | The impacts of dam releases from re-operation scenarios of the Akosombo and Kpong hydropower facilities on downstream communities along the Lower Volta River were examined through hydrodynamic modelling using the HEC-RAS hydraulic model. The model was used to simulate surface water elevation along the river reach for specified discharge hydrographs from proposed re-operation dam release scenarios. The morphology of the river and its flood plains together with cross-sectional profiles at selected river sections were mapped and used in the hydrodynamic modelling. In addition, both suspended and bed-load sediment were sampled and analysed to determine the current sediment load of the river and its potential to carry more sediment. The modelling results indicate that large areas downstream of the dam including its flood plains would be inundated if dam releases came close to or exceeded 2300 m3/s. It is therefore recommended to relocate communities along the banks and in the flood plains of the Lower Volta River when dam releases are to exceed 2300 m3/s. Suspended sediment transport was found to be very low in the Lower Volta River and the predominant soil type in the river banks and bed is sandy soil. Thus, the geomorphology of the river can be expected to change considerably with time, particularly for sustained high releases from the Akosombo and Kpong dams. The results obtained from this study form a basis for assessing future sedimentation problems in the Lower Volta River and for underpinning the development of sediment control and management strategies for river basins in Ghana. Keywords: Geomorphology, HEC-RAS model, Dam release, Floodplain, Lower Volta River, Ghana |
| first_indexed | 2024-12-21T19:46:25Z |
| format | Article |
| id | doaj.art-806d7cd3b2d84014b57fa459e341a399 |
| institution | Directory Open Access Journal |
| issn | 2214-5818 |
| language | English |
| last_indexed | 2024-12-21T19:46:25Z |
| publishDate | 2017-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Hydrology: Regional Studies |
| spelling | doaj.art-806d7cd3b2d84014b57fa459e341a3992022-12-21T18:52:19ZengElsevierJournal of Hydrology: Regional Studies2214-58182017-12-011419Floodplain hydrodynamic modelling of the Lower Volta River in GhanaFrederick Yaw Logah0Akurugu Barnabas Amisigo1Emmanuel Obuobie2Kwabena Kankam-Yeboah3Corresponding author.; CSIR Water Research Institute, P. O. Box M. 32, Accra, GhanaCSIR Water Research Institute, P. O. Box M. 32, Accra, GhanaCSIR Water Research Institute, P. O. Box M. 32, Accra, GhanaCSIR Water Research Institute, P. O. Box M. 32, Accra, GhanaThe impacts of dam releases from re-operation scenarios of the Akosombo and Kpong hydropower facilities on downstream communities along the Lower Volta River were examined through hydrodynamic modelling using the HEC-RAS hydraulic model. The model was used to simulate surface water elevation along the river reach for specified discharge hydrographs from proposed re-operation dam release scenarios. The morphology of the river and its flood plains together with cross-sectional profiles at selected river sections were mapped and used in the hydrodynamic modelling. In addition, both suspended and bed-load sediment were sampled and analysed to determine the current sediment load of the river and its potential to carry more sediment. The modelling results indicate that large areas downstream of the dam including its flood plains would be inundated if dam releases came close to or exceeded 2300 m3/s. It is therefore recommended to relocate communities along the banks and in the flood plains of the Lower Volta River when dam releases are to exceed 2300 m3/s. Suspended sediment transport was found to be very low in the Lower Volta River and the predominant soil type in the river banks and bed is sandy soil. Thus, the geomorphology of the river can be expected to change considerably with time, particularly for sustained high releases from the Akosombo and Kpong dams. The results obtained from this study form a basis for assessing future sedimentation problems in the Lower Volta River and for underpinning the development of sediment control and management strategies for river basins in Ghana. Keywords: Geomorphology, HEC-RAS model, Dam release, Floodplain, Lower Volta River, Ghanahttp://www.sciencedirect.com/science/article/pii/S2214581817301635 |
| spellingShingle | Frederick Yaw Logah Akurugu Barnabas Amisigo Emmanuel Obuobie Kwabena Kankam-Yeboah Floodplain hydrodynamic modelling of the Lower Volta River in Ghana Journal of Hydrology: Regional Studies |
| title | Floodplain hydrodynamic modelling of the Lower Volta River in Ghana |
| title_full | Floodplain hydrodynamic modelling of the Lower Volta River in Ghana |
| title_fullStr | Floodplain hydrodynamic modelling of the Lower Volta River in Ghana |
| title_full_unstemmed | Floodplain hydrodynamic modelling of the Lower Volta River in Ghana |
| title_short | Floodplain hydrodynamic modelling of the Lower Volta River in Ghana |
| title_sort | floodplain hydrodynamic modelling of the lower volta river in ghana |
| url | http://www.sciencedirect.com/science/article/pii/S2214581817301635 |
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