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Geosciences -Environnement- Toulouse |  |
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Geosciences -Environnement- Toulouse | |
| HAL: ird-00402391, version 1 |
| DOI: 10.1016/j.jhydrol.2009.06.045 |
| IRD Horizon id: fdi:010048234 |
| Detailed view |  Export this paper |
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| Journal of Hydrology (2009) HYDROL 16662 |
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| The AMMA-CATCH Gourma observatory site in Mali : relating climatic variations to changes in vegetation, surface hydrology, fluxes and natural resources |
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E. Mougin 1Pierre Hiernaux 1 |
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| The Gourma site in Mali is one of the 3 instrumented meso-scale sites deployed in West- Africa as part of the African Monsoon Multidisciplinary Analysis (AMMA) project. Located both in the Sahelian zone sensu stricto, and in the Saharo-Sahelian transition zone, the Gourma meso-scale window is the northernmost site of the AMMA-CATCH observatory reached by the West-African monsoon. The experimental strategy includes deployment of a variety of instruments, from local to meso-scale, dedicated to monitoring and documentation of the major variables characterizing the climate forcing, and the spatio-temporal variability of surface processes and state variables such as vegetation mass, leaf area index (LAI), soil moisture and surface fluxes. This paper describes the Gourma site, its associated instrumental network and the research activities that have been carried out since 1984. In the AMMA project, emphasis is put on the relations between climate, vegetation and surface fluxes. However, the Gourma site is also important for development and validation of satellite products, mainly due to the existence of large and relatively homogeneous surfaces. The social dimension of the water resource uses and governance is also briefly analyzed, relying on field enquiry and interviews. The climate of the Gourma region is semi-arid, daytime air temperatures are always high and annual rainfall amounts exhibit strong inter-annual and seasonal variations. Measurements sites organized along a north-south transect reveal sharp gradients in surface albedo, net radiation, vegetation production, and distribution of plant functional types. However, at any point along the gradient, surface energy budget, soil moisture and vegetation growth contrast between two main types of soil surfaces and hydrologic systems. On the one hand, sandy soils with high water infiltration rates and limited run-off support almost continuous herbaceous vegetation with scattered woody plants. On the other hand, water infiltration is poor on shallow soils, and vegetation is sparse and discontinuous, whith more concentrated run-off that ends in pools or low-lands within structured endorheic watersheds. Land surface in the Gourma is characterized by rapid response to climate variability, strong intra-seasonal, seasonal and interannual variations in vegetation growth, soil moisture and energy balance. Despite the multi-decadal drought, which still persists, ponds and lakes have increased, the grass cover has largely recovered, and there are signs of increased tree cover at least in the low lands. |
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| 1: | Centre d'études spatiales de la biosphère (CESBIO) |
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CNRS : UMR5126 – Institut de recherche pour le développement [IRD] – CNES – Observatoire Midi-Pyrénées – INSU – Université Paul Sabatier [UPS] - Toulouse III |
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| 2: | Laboratoire d'étude des transferts en hydrologie et environnement (LTHE) |
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CNRS : UMR5564 – OSUG – INSU – Université Joseph Fourier - Grenoble I – Institut National Polytechnique de Grenoble (INPG) – Institut de recherche pour le développement [IRD] : UR012 |
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| 3: | IRD - Mali (IRD) |
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Institut de recherche pour le développement [IRD] |
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| 4: | Géomatériaux et géologie de l'ingénieur (GGI) |
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CNRS : FRE2455 |
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| 5: | Laboratoire des Mécanismes et Transfert en Géologie (LMTG) |
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CNRS : UMR5563 – Observatoire Midi-Pyrénées – Université Paul Sabatier [UPS] - Toulouse III – Institut de recherche pour le développement [IRD] : UMR154 |
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| 6: | Centro de Estudios Avanzados en Zonas Aridas |
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centro de Estudios |
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| 7: | Groupe d'étude de l'atmosphère météorologique (CNRM-GAME) |
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CNRS : URA1357 – INSU – Météo France |
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| 8: | Laboratoire Ecologie Fonctionnelle et Environnement (EcoLab) |
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PRES Université de Toulouse – Institut National Polytechnique de Toulouse - INPT – Université Paul Sabatier [UPS] - Toulouse III – Observatoire Midi-Pyrénées – CNRS : UMR5245 |
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| 9: | Institut d'Economie Rurale - Mali (IER) |
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institut Economie |
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| 10: | Direction Nationale de la Météorologie |
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Direction Nationale de la Météorologie |
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| 11: | Institut Polytechnique rural Mali |
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Institut Polytechnique rural |
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| 12: | Center for Ecology and Hydrology (CEH) |
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CEH |
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| 13: | Natural Resource Ecology Laboratory |
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Natural Resource Ecology Laboratory |
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| 14: | Ecologie, Systématique et Evolution (ESE) |
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CNRS : UMR8079 – Université Paris XI - Paris Sud – Ecole Nationale du Génie Rural des Eaux et Forêts |
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| 15: | Laboratoire d'aérologie (LA) |
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CNRS : UMR5560 – Observatoire Midi-Pyrénées – INSU – Université Paul Sabatier [UPS] - Toulouse III |
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| 16: | Hydrosciences Montpellier (HSM) |
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CNRS : UMR5569 – Institut de recherche pour le développement [IRD] – Université Montpellier II - Sciences et techniques |
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| subject | : | Life Sciences/Ecology, environment/Ecosystems |
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| Sahel – AMMA – Mali – Gourma – vegetation – rainfall – fluxes – long term monitoring – water resource. |
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| Attached file list to this document: | |||||
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| ird-00402391, version 1 | |
| http://hal.ird.fr/ird-00402391 | |
| oai:hal.ird.fr:ird-00402391 | |
| From: Dominique Bruel | |
| Submitted on: Tuesday, 7 July 2009 11:59:26 | |
| Updated on: Tuesday, 7 July 2009 12:34:56 | |
