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Description

Main objective

This project aims at evaluating the respective roles of the recent evolution of climatic conditions and of changes in land-use and agricultural practices during the last 50 years on aeolian erosion and soil resources in the Sahel. The main question we want to adresse is : How did environmental changes impact aeolian erosion of Sahelian soils ?

Method 

This project is built on pre-existing models of aeolian erosion, Sahelian natural and cropped vegetation developed by the partners. These models will be combined and optimized to reach the objective of the project. Their application on the Sahelian region requires specific work to document and/or parameterize the input parameters, in particular precipitation and surface wind fields linked to the convective activity. The validation of the simulations will be based on the large data set of observations acquired during the AMMA international program, satelllite data and field measurements implemented in pasture lands in Niger. For the past period, the focus will be on the capability of the models to reproduce very contrasted situations in terms of climate and land-use.

Structure

The project is organized in 6 Work Packages. WP0 is dedicated to the management and coordination of the project. It will also have in charge the relationships with African partners. Dissemination and valorization of the results of the project is another responsibility of this WP. The different developments conducted to improve parameterizations in the initial models (STEP, SARRA-H, DPM) are the main activities of WP1. An important task of this WP will be to ensure the consistency of the coupling and
interactions between the models. The objectives of WP2 are to define and setup data sets of input data required by the models and, in particular, to develop methods for improving the input data
whose quality was found unsatisfactory in previous work (e.g. surface wind). The simulation setup will be designed in WP3, in order to perform the simulations for present-day conditions and the simulations
that reproduce the main changes observed during the last 5 decades. WP4 aims at evaluating the simulations from WP3. A large part of the work will be to analyze the validation datasets for the present period using available national and international databases.
For the past periods, datasets will be collected and tested for consistency before being used to validate the simulations. WP5 is in charge of the analyses of the simulations, after the validation step, in order to assess the role of the different factors acting on wind erosion in the Sahel. It will discuss the relative role of climate change and land-use in the variation of wind erosion and dust emissions over the last fifty years.