Dial Niang^1,, Amadou Keita¹, Chaim Vivien Doto¹, Hamma Yacouba¹

This article deals with the spatio-temporal variability of actual evapotranspiration on sandy veneers in the Burkinabe Sahel characterized by a large variability of rainfall and exceptional dry conditions according to the seasons. In order to establish a water balance, a tensio-neutronic device was deployed on seven (07) sites located on three (03) surface states (Unprotected grazed area, Restored fenced area and Protected area). Results showed a difference in the behavior of the actual evapotranspiration during the drying phase on the different surface states. Indeed, the presence of superficial film (site S1) significantly limits water infiltration. On desiccation sites (S3, S5, S6 and S7) characterized by the scattered or abundant presence of vegetation, the absence of indurated superficial film creates more favorable conditions for infiltration which results in a more or less significant accumulation of water in the soil. As for the partially encrusted sites (S2 and S4), we observed an intermediate behavior with respect to the other two sites with more or less water storage in the soil.

dry spells, soil water content, soil physic, evapotranspiration, sahel