Hydrodynamic and Erosive Behavior of Vertisols in the Wadi Sra Catchment (Central Rif, Morocco) – Analysis of the Rainfall Simulation Results

The objective of this work was to analyze the hydrodynamic and erosive behavior of soils in the wadi Sra catchment (Central Rif, Morocco) using a mini ramp rain simulator on micro-plots of 1 m2. The plots were selected on vertisols with a slope (between 17 and 33%), considering four types of land use: cannabis cultivation, cereal cultivation, fallow land and abandoned land, with the aim of comparing and determining the effects of the land use types on infiltrability and sediment production. The simulation tests were carried out during each season, due to the variability of cultivation practices, surface conditions and prior soil moisture from one season to another. Before each simulation, the surface condition of the concerned plots was checked; it is a question of raising the rate of closed or open surfaces and covered or bare surfaces according to the quadrat points method. Laboratory tests allowed identifying the physico-chemical properties of the soil, the initial humidity, the bulk density and the porosity. The results obtained show that the final infiltration is characterized by a significant variation, between (8.32 mm/h and 70.40 mm/h). Low values concern abandoned and fallow land and very high values are recorded on plowed land (cannabis and cereal cultivation). In addition, solid transport recorded significant spatio-temporal variations, between (5.15 and 157 g/l); the maximum average values are recorded in the cannabis cultivation plots, followed by abandoned land, then fallow land and cereal cultivation land.