Estimation of the Potential Erosion in the N’djili River (Kinshasa) Watershed by Integration of the Wischmeier Equation in the Geographic Information System and Remote Sensing.

This study was conducted in the watershed of N’djili river, in order to identify and quantify the risks of water erosion for a sustainable land management. Specifically, it’s important to rate the major factors and potential erosion using the Universal Soil Loss Equation (USLE), coupled with GIS and remote sensing on this watershed.

The calculated results indicate the order of magnitude of parameters which generate the rain erosivity varying from 124 to 151 while soil erodibility rises to 0.2. In some parts of the land, topographic factor reach the value of 30.89. Following cultural practices in bands, the cropping factor can reach the maximum value of 1 unit while conservative factor ranges from 0.25 to 0.45.

As far as the potential erosion is concerned, calculated soil loss spread from 2 to about 180t/ ha/year. Data analysis show that over 99 % of the watershed surface is near the threshold of soil loss in the intertropical region estimated as 20 t/ha/ year. However, it appears that 1 % of the watershed area is gullied on uncovered surface or on urbanization area. It is certain that through this study, some control methods could be considered in order to assume soil conservation. Télécharger l'article