Spatial variation in wind-blown sediment transport in geomorphic units in northern Burkina Faso using geostatistical mapping

Due to rapid population growth, farmers in northern Burkina Faso have started to cultivate areas less suitable for agricultural production. In fields, situated at various geomorphologic settings, erodibility is highly variable resulting in variable wind-blown sediment fluxes. Furthermore, at a field scale, observations of wind-blown mass transport often show spatial variation. This study examines the mass transport rates in three main geomorphic units in northern Burkina Faso and the spatial variation in mass transport in a single geomorphic unit. In the 2001 rainy season, wind-blown mass transport was measured on fields in the valley and on the dune and on a degraded plot in the Katchari catchment. Differences in total mass transport between geomorphic units are related to sediment availability in and around the research plots. Geostatistical theory was applied to produce event-based maps of mass transport by stochastically simulating the spatial correlation structure. The conditionally simulated maps showed large spatial variation in mass transport. It is concluded that, in the Sahelian region of northern Burkina Faso, it will be useful to distinguish erosion and deposition areas in the field. So to be able to deal with spatial variation, a wind erosion model suitable for the Sahelian situation should at least have a spatial component. Furthermore, differences in intensity of sediment transport between geomorphic units indicate that the user should have information about the geomorphic settings of a field to be able to set the boundary conditions