Evaluation of material flows in the Mé River watershed (Ivory Coast)

Abstract Soil erosion by precipitation, rainfall and runoff is a widespread phenomenon in different countries of the world. It becomes disastrous in particular on the slopes because of the torrentiality of the flow, of the strong vulnerability of the grounds (soft rocks, fragile grounds, steep slopes). The present study has for objective: The analysis of the data of concentrations of sediments in suspension are measured at the station of the rivers highlights relations, linking the concentration (or the solid flow) of the sediments in suspension to the liquid flow and to quantify the seasonal, monthly and interannual and intra annual variation of the surface degradation. Annual tonnage estimates of solids loads to the Mé were derived from the power law for all seasons. From this deduction, the annual quantities of sediment transported by the Mé from 2015/2017 is 7.06.106 t/year, or a specific degradation of 1.79.103 t/km²/year. On the other hand, in 2017, the value of this solid input is 3.06.106 t/year. However, the annual solid input is estimated at 7063.03.103 t/year with a specific degradation of 1784.47 t/km²/year at the Mé from 2015 to 2017.