Soil erosion by water is soil loss due to water pulling and transporting the soil to a deposition site. This is the major cause of soil degradation and siltation of hydro systems. Knowledge of this phenomenon is therefore essential for better management of dam water resources. The site of the study is the watershed of the hydro-agricultural dam of Babadou. It is a small agricultural catchment area of 1630 ha in the center-west of Côte d'Ivoire. The objective of this work is to highlight the erosion by water risks and sediment transport. Thus, the Universal Soil Loss Equation (USLE) was not only used to model the factors involved in the erosion process, but also for the calculation of soil losses through a Geographic Information System (GIS). The results show an average soil loss of 6.9 t/ha/year, which represents a soil loss of 11247 t/year in the Babadou dam watershed. In addition, the soil loss map, carried out, highlights the area’s most sensitive to erosion with soil losses reaching 767.4 t/ha/year. They are generally at the regions of bare soils and areas of annual crops. The sustainability of the water resource of the hydro-agricultural dam at Babadou requires the correction of vegetation cover and the use of anti-erosion practices in these areas, with a view to reducing soil loss and sediment flow.

The current work aims to map the different forms of erosion which are expressed in the district of Attecoube. From georeferenced aerial photographs and based on the concepts of texture and structure, the different forms of erosion were discriminated on the screen. Many field visits, with tablets, GPS and tape measure (for measurements) allowed checking and adjusting the interpretations made on screen. These high-tech devices were also used for capturing images. Then, we superimposed the erosion forms map at the slopes map of the study area. Three main forms of erosion were revealed: - diffuse erosion covers 14,32% of the study area; - gully erosion which manifest itself on every slope range, covers 66.39% of the Attecoube district; - mass wasting localised, cover only 06.82% of the study area.

This study aims to explain the dynamics of the local climate in southwestern of Côte d'Ivoire in a context of strong human pressure and climate variability. The methodological approach, based on the use of climate data an opportunity to discuss the impact of environmental change on natural resources. Southwestern Côte d'Ivoire has suffered a sharp change in vegetation cover. Since the climate out of 1970, the region observed spatiotemporal variation of rainfall regularly changing down. She sees an emphasis on the occurrence of extreme weather events, especially in terms of temperatures. These changes have resulted in a reduction of consecutive wet months and threatening storm agriculture practice in this area.