Effects of watershed management practices in reducing the erosion and sedimentation (Case Study: Alikandi Boukan Watershed)

Soil erosion reduces the fertility of upstream soils and damages them by sedimentation downstream. In order to evaluate the impact of watershed mechanical operations on erosion control and sediment reduction, field surveys were performed to evaluate the performance of each structure in the Bukan Alikandi watershed. Soil erosion and sedimentation status was evaluated using MPSIAC model and sediment volumetric measurements were carried out behind mechanical structures to evaluate the effect of watershed management. Evaluation results showed that mechanical operations were able to reduce soil erosion and sedimentation percentage. Due to the construction of check dams at Alikandi watershed, a total of 75806.5 cubic meters of controlled sediment is about 42%. The volume of sediment control per unit volume was 0.21 m3 for gabion dams, 0.77 for rock check dams with cement cover and 0.43 m3 for cement check dams, respectively. Therefore, rock check dams with cement cover had the greatest impact on the basin. Finally, it is suggested that in the desired basin and basins with similar conditions, for the positive impact and better performance of executive measures, a combination of mechanical and biological be implemented in the area.