Mamadou CISS returns to GET

Last November, the Geosciences Environment Toulouse (GET) laboratory welcomed back Dr Mamadou Ciss for a 1-month secondment as part of the INSA project.

Mamadou Ciss is a research fellow in mathematical and statistical modelling at the Institut Sénégalais de Recherches Agricoles (ISRA) in Dakar, Senegal, specializing in spatially explicit mathematical models for ecological systems.

While in Toulouse, Mamadou worked with Eric Mougin (GET) and Claire Delon (LAERO) on relating the Sahelian Transpiration, Evaporation and Productivity (STEP) model for the Dahra region to variation in stock population numbers throughout the year. In West Africa, mobility is an essential component of animal production and trade that can potentially affect the whole region. Animals, mainly adults, are moved for a variety of reasons: in search of better grazing areas (i.e. transhumance), to be sold alive on the market for commercial reasons, during religious festivities such as Tabaski, or Magal in Touba (city lacted close to Dahra), or to be exchanged between families and relatives. In Senegal, Dahra experiences large transient animal populations due to its strategic position in trade and transhumance (Figure 1). Consequently, there is an impact on the animal load and hence on the nitrogen at soil level.

Preliminay results show that simulated soil nitrogen content corresponds better to observed data when temporal variation in stock composition due to religious festivals (e.g. more sheep during the month of Tabaski, or more cattle during Magal) is accounted for, compared to when stock composition (percentage of each animal type) is assumed to remain constant throughout the year.