Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate change
Abstract Accurate assessment of water resources at the watershed level is crucial for effective integrated watershed management. While semi-distributed/distributed models require complex structures and large amounts of input data, conceptual models have gained attention as an alternative to watershe...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-02-01
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| Series: | Environmental Sciences Europe |
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| Online Access: | https://doi.org/10.1186/s12302-024-00848-2 |
| _version_ | 1797275458089254912 |
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| author | Serigne Mory Khouma Séne Cheikh Faye Chaitanya B. Pande |
| author_facet | Serigne Mory Khouma Séne Cheikh Faye Chaitanya B. Pande |
| author_sort | Serigne Mory Khouma Séne |
| collection | DOAJ |
| description | Abstract Accurate assessment of water resources at the watershed level is crucial for effective integrated watershed management. While semi-distributed/distributed models require complex structures and large amounts of input data, conceptual models have gained attention as an alternative to watershed modeling. In this paper, the performance of the GR4J conceptual model for runoff simulation in the Gambia watershed at Simenti station is analyzed over the calibration (1981–1990) and validation period (1991–2000 and 2001–2010). The main inputs to conceptual models like GR4J are daily precipitation data and potential evapotranspiration (PET) measured from the same catchment or a nearby location. Calibration of these models is typically performed using the Nash–Sutcliffe daily efficiency with a bias penalty as the objective function. In this case, the GR4J model is calibrated using four optimization parameters. To evaluate the effectiveness of the model's runoff predictions, various statistical measures such as Nash–Sutcliffe efficiency, coefficient of determination, bias, and linear correlation coefficient are calculated. The results obtained in the Gambia watershed at Simenti station indicate satisfactory performance of the GR4J model in terms of forecast accuracy and computational efficiency. The Nash–Sutcliffe (Q) values are 0.623 and 0.711 during the calibration period (1981–1990) and the validation period (1991–2000), respectively. The average annual flow observed during the calibration period is 0.385 mm while it increases with a value of 0.603 mm during the validation period. As for the average flow simulated by the model, it is 0.142 mm during the calibration period (i.e., a delay of 0.142 mm compared to the observed flow), 0.626 mm in the validation period (i.e., an excess of 0.023 mm compared to the observed flow). However, this study is significant because it shows significant changes in all metrics in the watershed sample under different scenarios, especially the SSP245 and SSP585 scenarios over the period 2021–2100. These changes suggest a downward trend in flows, which would pose significant challenges for water management. Therefore, it is clear that sustainable water management would require substantial adaptation measures to cope with these changes. |
| first_indexed | 2024-03-07T15:14:38Z |
| format | Article |
| id | doaj.art-0805b4fe7f934c3395e50037e0d85f5b |
| institution | Directory Open Access Journal |
| issn | 2190-4715 |
| language | English |
| last_indexed | 2024-03-07T15:14:38Z |
| publishDate | 2024-02-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Environmental Sciences Europe |
| spelling | doaj.art-0805b4fe7f934c3395e50037e0d85f5b2024-03-05T17:58:11ZengSpringerOpenEnvironmental Sciences Europe2190-47152024-02-0136112110.1186/s12302-024-00848-2Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate changeSerigne Mory Khouma Séne0Cheikh Faye1Chaitanya B. Pande2Department of Geography, U.F.R. Sciences et Technologies, Laboratory of Geomatics and Environment, Assane Seck Univesity of ZiguinchorDepartment of Geography, U.F.R. Sciences et Technologies, Laboratory of Geomatics and Environment, Assane Seck Univesity of ZiguinchorNew Era and Development in Civil Engineering Research Group, Scientific Research Center, Al-Ayen UniversityAbstract Accurate assessment of water resources at the watershed level is crucial for effective integrated watershed management. While semi-distributed/distributed models require complex structures and large amounts of input data, conceptual models have gained attention as an alternative to watershed modeling. In this paper, the performance of the GR4J conceptual model for runoff simulation in the Gambia watershed at Simenti station is analyzed over the calibration (1981–1990) and validation period (1991–2000 and 2001–2010). The main inputs to conceptual models like GR4J are daily precipitation data and potential evapotranspiration (PET) measured from the same catchment or a nearby location. Calibration of these models is typically performed using the Nash–Sutcliffe daily efficiency with a bias penalty as the objective function. In this case, the GR4J model is calibrated using four optimization parameters. To evaluate the effectiveness of the model's runoff predictions, various statistical measures such as Nash–Sutcliffe efficiency, coefficient of determination, bias, and linear correlation coefficient are calculated. The results obtained in the Gambia watershed at Simenti station indicate satisfactory performance of the GR4J model in terms of forecast accuracy and computational efficiency. The Nash–Sutcliffe (Q) values are 0.623 and 0.711 during the calibration period (1981–1990) and the validation period (1991–2000), respectively. The average annual flow observed during the calibration period is 0.385 mm while it increases with a value of 0.603 mm during the validation period. As for the average flow simulated by the model, it is 0.142 mm during the calibration period (i.e., a delay of 0.142 mm compared to the observed flow), 0.626 mm in the validation period (i.e., an excess of 0.023 mm compared to the observed flow). However, this study is significant because it shows significant changes in all metrics in the watershed sample under different scenarios, especially the SSP245 and SSP585 scenarios over the period 2021–2100. These changes suggest a downward trend in flows, which would pose significant challenges for water management. Therefore, it is clear that sustainable water management would require substantial adaptation measures to cope with these changes.https://doi.org/10.1186/s12302-024-00848-2Water resourcesClimate changeFlowGR4JCMIP6Gambia Basin |
| spellingShingle | Serigne Mory Khouma Séne Cheikh Faye Chaitanya B. Pande Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate change Environmental Sciences Europe Water resources Climate change Flow GR4J CMIP6 Gambia Basin |
| title | Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate change |
| title_full | Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate change |
| title_fullStr | Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate change |
| title_full_unstemmed | Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate change |
| title_short | Assessment of current and future trends in water resources in the Gambia River Basin in a context of climate change |
| title_sort | assessment of current and future trends in water resources in the gambia river basin in a context of climate change |
| topic | Water resources Climate change Flow GR4J CMIP6 Gambia Basin |
| url | https://doi.org/10.1186/s12302-024-00848-2 |
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