Previous work

Previous work I have done focused on:

Assessment of the modification of water and vegetation cycles in the Sahel under climate and land-use changes

Water and vegetation cycles are intimately linked. In the Sahel region, they are essentially conditioned by climatic variability and changes in land-use. Within the context of climatic change, it is important to understand the evolution of water resources to study its impact on food production systems, especially in the Sahel region where population growth is, and will continue to be high. Within the AMMA research program (“Analyses multidisciplinaires de la mousson africaine”, in French), an important experimental program has been set up in Niger to study the water cycle and land surface properties and processes (Cappelaere et al., 2009). Hydrologic and plant growth models have also been developed that can simulate the main water and energy budgets and exchanges between the surface (soil and vegetation) and the atmosphere. Within this context, and within the ESCAPE project, my current work (2013-2014) focuses on looking at the past (1950-2010) and future (2010-2050) evolution of water and ecological resources in the Sahel under climate and land use changes. To do so, I am using SVAT models (SiSPAT: Braud et al., 1995 ; STEP: Mougin et al, 1995 ; SARRAH: Dingkuhn et al 2005 ), the CMIP5 climatic models and the extensive database acquired during the AMMA research programs to model the water and energy cycles for the two main ecosystems found in the Sahel (millet and fallow), under contrasted climate scenarios.

Quantifying the impact of floods on fodder production in the Tana River Delta, Kenya

Wetlands are a vital resource for many pastoralists in Sub-Saharan Africa as they provide dry-season grazing zones. As floods are essential for wetland ecosystems, the assessment of water abstraction and hydroelectric infrastructure on downstream flooding dynamics is crucial. Yet, scarce data, environmental variability and the lack of models make this challenging. This research contributed to quantifying the influence of changing water resources on fodder production of floodplain grasslands in the Tana River Delta, Kenya. 1/ Growth characteristics of floodplain grasslands of Echinochloa stagnina (Retz) P. Beauv. for different flood and management options were determined and a quantification of their productivity achieved. A plant growth model adapted to tropical floodplain conditions and perennial C4 grasses was developed, and is the first known physiologically based model for floodplain grasslands. 2/ Hydrological processes of ecological importance (flood extent, timing, duration, frequency) were characterized in a poorly gauged basin using a water-balance model combined with remote-sensing techniques, despite precise knowledge of discharge rates, topography and a high cloud cover. 3/ A preliminary analysis explored different flooding scenarios and their impact on fodder production through the use of simple ecosystem service indicators. This PhD research (2010-2013) contributed to the repertoire of wetland ecosystem services by building biophysically based simulation models and exploring possible scenarios in a region of the world and an ecosystem where these type of evaluations are rare.

Check out this short video explaining my PhD work!

You can also check out this video on participatory science in the Tana River Delta.

Photos of the Tana River Delta:

References:

Braud I., A.C. Dantas-Antonino, M. Vauclin, J.L. Thony, and P. Ruelle, 1995. A simple soil-plant-atmosphere transfer model (SiSPAT) development and field verification, Journal of Hydrology, 166, 213-250.

Cappelaere B, Descroix L., Lebel T., et al. (2009). The AMMA-Catch experiment in the cultivated Sahelian area of south-west Niger - Strategy, implementation, site description, main results. Journal of Hydrology, 375, 34-51.

Daily G.C.. Nature’s Services: Societal Dependence On Natural Ecosystems. Island Press, Washington D.C., 1997.

Dingkuhn, M., Baron, C., Bonnal, V., Maraux, F., Sarr, B., Sultan, B., Clopes, A., Forest, F., 2003. Decision-support tools for rainfed crops in the Sahel at the plot and regional scales. In: Struif-Bontkes, T.E., Wopereis, M.C.S. (Eds.), A Practical Guide to Decision-support Tools for Agricultural Productivity and Soil Fertility Enhancement in Sub-Saharan Africa, IFDC, CTA, pp.127–139.

Millennium Ecosystem Assessment. 2005 Ecosystems and human well-being: Synthesis. Technical report, World Resources Institute, Washington, DC.

Mougin E., Loseen D., Rambal S., Gaston A., Hiernaux, P. 1995. A regional sahelian grassland model to be coupled with multispectral satellite data .1. model description and validation. Remote Sensing of Environment, 52(3):181–193.