The AMMA-CATCH Gourma observatory site in Mali: Relating climatic variations to changes in vegetation, surface hydrology, fluxes and natural resources

JOURNAL OF HYDROLOGY

卷:375

Article

Mougin, E.¹  Hiernaux, P.¹  Kergoat, L.¹  Grippa, M.¹  de Rosnay, P.¹  Timouk, F.¹  Le Dantec, V.¹  Demarez, V.¹  Lavenu, F.¹  Arjounin, M.²  Lebel, T.²  Soumaguel, N.³  Ceschia, E.¹  Mougenot, B.¹  Baup, F.¹  Frappart, F.¹  Gardelle, J.¹  Gruhier, C.¹  Jarlan, L.¹  Mangiarotti, S.^7,8,9,10  Sanou, B.¹  Tracol, Y.⁴  Guichard, F.⁵  Trichon, V.⁶  Diarra, L.¹¹  Soumare, A.¹¹  Koite, M.¹²  Dembele, F.¹³  Lloyd, C.¹⁴  Hanan, N. P.¹⁵  Damesin, C.¹⁶  Delon, C.¹⁷  Serca, D.¹⁷  Galy-Lacaux, C.¹⁷  Seghieri, J.¹⁸  Becerra, S.^7,8,9,10  Dia, H.^7,8,9,10  Gangneron, F.^7,8,9,10  Mazzega, P.^7,8,9,10 

[1] CNRS CNES IRD UPS, Ctr Etud Spatiales Biosphere, UMR 5126, F-31401 Toulouse 4, France

[2] CNRS UJF IRD INPG, UMR 5564, Lab Tranferts Hydrol & Environm, F-38041 Grenoble, France

[3] Ctr IRD, Bamako, Mali

[4] Ctr Estudios Avanzados Zonas Aridas, La Serena, Chile

[5] CNRS Meteo France, CNRM GAME, Toulouse, France

[6] Univ Toulouse 3, CNRS UPS INPT, UMR 5245, ECOLAB,Lab Ecol Fonct, F-31062 Toulouse 9, France

[7] CNRS IRD UPS, UMR 5563, Lab Mecanismes & Transferts Geol, F-31400 Toulouse 4, France

[8] Univ Toulouse, UPS OMP, LMTG, F-31400 Toulouse, France

[9] LMTG, CNRS, F-31400 Toulouse, France

[10] LMTG, IRD, F-31400 Toulouse, France

[11] Inst Econ Rurale, Bamako, Mali

[12] Direct Natl Meteorol, Bamako, Mali

[13] Inst Polytech Rural, Katibougou, Mali

[14] Ctr Ecol & Hydrol, Wallingford OX10 8BB, Oxon, England

[15] Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA

[16] Univ Paris 11, CNRS, UMR 8079, F-91405 Orsay, France

[17] CNRS UPS, UMR 5560, Lab Aerol, F-31400 Toulouse, France

[18] Univ Montpellier 2, CNRS IRD UM1 UM2, UMR 5569, HSM, F-34095 Montpellier, France

关键词: Sahel;    AMMA;    Mali;    Gourma;    Vegetation;    Rainfall;   

DOI  :  10.1016/j.jhydrol.2009.06.045

来源: Elsevier

【 摘 要 】

The Gourma site in Mali is one of the three instrumented meso-scale sites deployed in West-Africa as part of the African Monsoon Multi-disciplinary 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, with 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 inter-annual 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. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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