Improved MPSIAC model for soil erosion rate assessment in semiarid zones

Erosion of soil by water is one of the most significant forms of soil degradation. The validity of the Modified Pacific South-West Inter-Agency Committee (MPSIAC) model for assessment of soil erosion rates has been demonstrated in many countries. We propose an improved version of the MPSIAC model to determine the erosion rate and expected sediment yield in two scenarios, conservative and adverse. Three microcatchments were selected from an arid semi-desert biome in Mexico, chosen for their advanced state of soil erosion by water and soil degradation. The improvements introduced to the MPSIAC model made field and laboratory work easier and can improve the methodology used for management of watersheds with similar conditions anywhere in the world. The improvements are related to selecting the microcatchment size, adding new categorization level of sediment yield, and calculating the time of rain concentration and modified erodibility factor K. The sensitivity analysis showed that runoff, surface erosion and channel erosion parameters are the most significant and soil factor K is the least sensitive parameter of the model. The improvements will support decision-making processes and selection of control practices that are best suited to the particular needs of each site and to preventing soil erosion risks.

Automated summary

Soil erosion by water is a significant form of soil degradation, and an improved version of the MPSIAC model has been proposed to assess erosion rates and sediment yield accurately. The improvements made to the model simplify field and laboratory work and can be applied to watershed management with similar conditions worldwide. The enhancements include selecting microcatchment size, adding a new categorization level for sediment yield, and calculating rain concentration time and modified erodibility factor K. Sensitivity analysis reveals that runoff, surface erosion, and channel erosion parameters are the most important, while soil factor K is the least sensitive parameter. These improvements will aid in decision-making and selecting appropriate soil erosion control measures for specific locations.