Dynamics of the transport of total suspended sediments in the Mefou watershed at Nkolbisson-Yaounde

This study carried out in the Mefou watershed aimed to assess the quantity of suspended solids in suspension. For this study, a water level gauge was installed at the main station at Etoud, four discharge measurements representing the seasons were carried out and water samples were collected. The maximum liquid discharge to the Lake Mefou was 3.92 m3/s observed during the long rainy season, while the minimum observed during the long dry season was 0.58 m3/s. Meanwhile, the maximum solid discharge to the Lake Mefou observed during the short rainy season was 598.8 mg/s and the minimum of 14.85 mg/s was observed in June during the short dry season. It is then evident that the amount of suspended sediments in the river is not proportional to the flow rate. The mobilization of solid particles in the watershed resulted in an annual total flux of 5.74 T/year into the lake reservoir. This result is not yet alarming for the reservoir lifespan but testify to the permanent activity of erosion in this environment caused by the combination of various natural and anthropogenic processes such as climate change and land use activities. HIGHLIGHTS The Mefou watershed is subject to erosion phenomena.; Liquid and solid flows change proportionally to precipitation.; Suspended matter concentrations are integrated into liquid flow rates to obtain solid discharges.; The temporal data which are the liquid flow and the solid flow are used to estimate the specific degradation.; The soil degradation process is not yet critical because it is a peri-urban environment.