Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins
<p>Analysis of reference evapotranspiration (ET<span class="inline-formula"><sub>0</sub>)</span> trends is essential for understanding the impacts of climate change on water resources. Thus, despite the continuous rise in temperatures, a decrease in evapotrans...
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Copernicus Publications
2024-04-01
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Series: | Proceedings of the International Association of Hydrological Sciences |
Online Access: | https://piahs.copernicus.org/articles/385/305/2024/piahs-385-305-2024.pdf |
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author | P. M. Ndiaye A. Bodian S. B. Diop L. Diop A. Dezetter A. Ogilvie K. Djaman |
author_facet | P. M. Ndiaye A. Bodian S. B. Diop L. Diop A. Dezetter A. Ogilvie K. Djaman |
author_sort | P. M. Ndiaye |
collection | DOAJ |
description | <p>Analysis of reference evapotranspiration (ET<span class="inline-formula"><sub>0</sub>)</span> trends is essential for understanding the impacts of climate change on water resources. Thus, despite the continuous rise in temperatures, a decrease in evapotranspiration is noted in some parts of the world. This contrast is called the “evaporation paradox” and is thought to be related to the variation in wind speed, relative humidity and solar radiation. The objective of this work is to analyze the annual and seasonal trends of ET<span class="inline-formula"><sub>0</sub></span> and climate variables at the scale of the Senegal, Gambia and Casamance river basins. The reanalyze data of NASA/POWER are used over the period 1984–2019. Mann Kendall's test and Sen slope were used to analyze trends in ET<span class="inline-formula"><sub>0</sub></span> and climate variables. Results show that on annual scale, ET<span class="inline-formula"><sub>0</sub></span> increases significantly in 32 % of the Senegal basin and decreases in less than 1 % of it. In contrast, in the Casamance and Gambia basins, the annual ET<span class="inline-formula"><sub>0</sub></span> drops by 65 % and 18 %, respectively. On an annual scale, temperature and relative humidity show an increasing trend over all basins while wind speed and radiation decrease significantly. This confirms the existence of the “evaporation paradox” in the three basins. This phenomenon is explained by the increase in relative humidity and the decrease in wind speed and solar radiation.</p> |
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spelling | doaj.art-f74ec8a1d990432f957ad4a56699b3e52024-04-18T12:57:10ZengCopernicus PublicationsProceedings of the International Association of Hydrological Sciences2199-89812199-899X2024-04-0138530531110.5194/piahs-385-305-2024Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River BasinsP. M. Ndiaye0A. Bodian1S. B. Diop2L. Diop3A. Dezetter4A. Ogilvie5K. Djaman6Laboratoire Leïdi “Dynamique des Territoires et Développement”, Université Gaston Berger (UGB), Saint-Louis BP 234, SenegalLaboratoire Leïdi “Dynamique des Territoires et Développement”, Université Gaston Berger (UGB), Saint-Louis BP 234, SenegalLaboratoire Leïdi “Dynamique des Territoires et Développement”, Université Gaston Berger (UGB), Saint-Louis BP 234, SenegalUFR S2ATA Sciences Agronomiques, de l'Aquaculture et des Technologies Alimentaires, Université Gaston Berger, Saint-Louis BP 234, SenegalHSM, Univ. Montpellier, IRD, CNRS, UFR Pharmacie, Bâtiment HYDROPOLIS, 15 avenue Charles Flahault, 34090 Montpellier, FranceUMR G-EAU, AgroParisTech, Cirad, University of Montpellier, IRD, INRAE, Montpellier SupAgro, 34196 Montpellier, FranceDepartment of Plant and Environmental Sciences, New Mexico State University, Agricultural Science Center at Farmington, P.O. Box 1018, Farmington, NM 87499, USA<p>Analysis of reference evapotranspiration (ET<span class="inline-formula"><sub>0</sub>)</span> trends is essential for understanding the impacts of climate change on water resources. Thus, despite the continuous rise in temperatures, a decrease in evapotranspiration is noted in some parts of the world. This contrast is called the “evaporation paradox” and is thought to be related to the variation in wind speed, relative humidity and solar radiation. The objective of this work is to analyze the annual and seasonal trends of ET<span class="inline-formula"><sub>0</sub></span> and climate variables at the scale of the Senegal, Gambia and Casamance river basins. The reanalyze data of NASA/POWER are used over the period 1984–2019. Mann Kendall's test and Sen slope were used to analyze trends in ET<span class="inline-formula"><sub>0</sub></span> and climate variables. Results show that on annual scale, ET<span class="inline-formula"><sub>0</sub></span> increases significantly in 32 % of the Senegal basin and decreases in less than 1 % of it. In contrast, in the Casamance and Gambia basins, the annual ET<span class="inline-formula"><sub>0</sub></span> drops by 65 % and 18 %, respectively. On an annual scale, temperature and relative humidity show an increasing trend over all basins while wind speed and radiation decrease significantly. This confirms the existence of the “evaporation paradox” in the three basins. This phenomenon is explained by the increase in relative humidity and the decrease in wind speed and solar radiation.</p>https://piahs.copernicus.org/articles/385/305/2024/piahs-385-305-2024.pdf |
spellingShingle | P. M. Ndiaye A. Bodian S. B. Diop L. Diop A. Dezetter A. Ogilvie K. Djaman Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins Proceedings of the International Association of Hydrological Sciences |
title | Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins |
title_full | Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins |
title_fullStr | Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins |
title_full_unstemmed | Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins |
title_short | Trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of Senegal: Senegal, Gambia and Casamance River Basins |
title_sort | trend analysis of reference evapotranspiration and climate variables in the main hydrosystems of senegal senegal gambia and casamance river basins |
url | https://piahs.copernicus.org/articles/385/305/2024/piahs-385-305-2024.pdf |
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