Anthropogenic Reservoirs of Various Sizes Trap Most of the Sediment in the Mediterranean Maghreb Basin
| Autor: | Yves Le Bissonnais, Estela Romero, Wolfgang Ludwig, François Bourrin, Mahrez Sadaoui |
|---|---|
| Přispěvatelé: | Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut de Recherche pour le Développement (IRD [ Madagascar])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), École pratique des hautes études (EPHE)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Sadaoui, Mahrez |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Mediterranean climate
lcsh:Hydraulic engineering 010504 meteorology & atmospheric sciences Mediterranean Maghreb Basin [SDE.MCG]Environmental Sciences/Global Changes 0208 environmental biotechnology Geography Planning and Development Drainage basin water fluxes sediment fluxes reservoirs hillside reservoirs sediment retention 02 engineering and technology Aquatic Science Structural basin 01 natural sciences Biochemistry Mediterranean sea lcsh:Water supply for domestic and industrial purposes lcsh:TC1-978 14. Life underwater Drainage 0105 earth and related environmental sciences Water Science and Technology Hydrology geography lcsh:TD201-500 geography.geographical_feature_category Sediment Arid 6. Clean water 020801 environmental engineering 13. Climate action Erosion Environmental science |
| Zdroj: | Water Water, MDPI, 2018, ⟨10.3390/w10070927⟩ Water, MDPI, 2018, 10 (7), ⟨10.3390/w10070927⟩ Water, 2018, 10 (7), ⟨10.3390/w10070927⟩ Water, Vol 10, Iss 7, p 927 (2018) Water 7 (10), . (2018) Volume 10 Issue 7 |
| ISSN: | 2073-4441 |
| Popis: | The purpose of this study is to obtain a spatially explicit assessment of the impact of reservoirs on natural river sediment fluxes to the sea in the Mediterranean Maghreb Basin (MMB), a region where both mechanical erosion rates and the anthropogenic pressure on surface water resources are high. We combined modeling of riverine sediment yields (sediment fluxes divided by the drainage basin area) and water drainage intensities in a 5&rsquo × 5&rsquo grid point resolution (~10 km × 10 km) with a compilation of existing reservoirs in the area, and calculated sediment trapping based on average water residence time in these reservoirs. A total number of 670 reservoirs could be assembled from various sources (including digitization from Google maps), comprising large-scale, small-scale and hillside reservoirs. 450 of them could be implemented in our modeling approach. Our results confirm that natural sediment yields are clearly above the world average, with the greatest values for Morocco (506 t km&minus 2 year&minus 1), followed by Algeria (328 t km&minus 1) and by Tunisia (250 t km&minus 1). Including dams in the downstream routing of suspended sediments to the sea reduces the natural sediment flux in the entire MMB to the sea from 96 to 36 Mt km&minus 1 year&minus 1, which corresponds to an average sediment retention of 62%. Trapping rates are highest in the Tunisian basin part, with about 72%, followed by the Algerian (63%) and the Moroccan basin parts (55%). Small reservoirs and hillside reservoirs are quantitatively important in the interception of these sediments compared to large reservoirs. If we only considered the dams included in the widely used Global Reservoir and Dam (GRanD) database which comprises mainly large reservoirs sediment retention behind dams would account for 36% of the natural suspended particulate matter (SPM) flux to the Mediterranean Sea. Our data reveal negative correlation between sediment retention and natural erosion rates among the three Maghreb countries, which can be explained by the greater difficulties to build dams in steep terrains where natural sediment yields are high. Although the lowest sediment retention rates are found in the Moroccan part of the MMB, it is probably here where riverine sediment starvation has the greatest impacts on coastline dynamics. Understanding the impact of dams and related water infrastructures on riverine sediment dynamics is key in arid zones such as the MMB, where global warming is predicted to cause important changes in the climatic conditions and the water availability. |
| Databáze: | OpenAIRE |
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