Modelling and quantification of soil water erosion using remote sensing in the Antanetibe Anativolo watershed

An erosion risk map is an essential tool against erosion.It makes it possible to have an overview of the problems and therefore to locate the sectors requiring priority intervention.The Antanetibe Anativolo watershed is a vast plain for rice cultivation, vast fields of food crops, and that even on the slopes of the hills surround it.Then, a region that supplies the capital with various agricultural products.For the sustainability of these activities given this potential and the presence of many lavakas that cut into the hills, the watershed was subject to a quantification of soil losses.The RUSLE model (Revised Universal Soil Loss Equation) was chosen in order to quantify and spatialize the water erosion processes at the catchment scale.A model widely implemented in the world, established at different scales and taking into account five determining parameters in the erosion process: the aggressiveness of precipitation, the erodibility of soils, the inclination and the length of the slope, the plant cover as well as the means put in place to fight against soil erosion.Three years are considered: 1990, 2006, 2022 to discern the evolution of erosion.The results show the average quantities of soil losses which are respectively 21,30 t/ha/year, 28,83 t/ha/year, and 43,08 t/ha/year.