Mitigating Erosion and Enhancing Sediment Retention: A Modeling Approach to Sustainable Land Management

Abstract Soil erosion poses a critical threat to global ecosystems, water resources, and agricultural productivity. This study assesses how Sustainable Land Management (SLM) mitigates sediment export and improves climate resilience using the InVEST Sediment Delivery Ratio (SDR) model across 12 Moroccan basins, representative of Mediterranean and arid environments. Our results identify significant hotspots in northern basins, where steep slopes and annual rainfall exceeding 500 mm drive erosion rates up to 14,700 tons per year, contributing substantially to downstream sediment transport. Conversely, arid basins exhibit lower erosion rates due to reduced precipitation and gentler slopes but struggle with sediment retention, with efficiencies below 50%. SLM interventions, such as a 25% increase in soil organic matter in agricultural lands, reduced sediment export by over 25% in northern basins and decreased sediment loss by more than 1 ton per hectare annually in vulnerable agricultural areas. These measures were especially effective in forested and terraced landscapes, enhancing sediment retention and minimizing impacts on reservoirs and water systems. This study underscores the dynamic nature of erosion and sediment transport under varying environmental and management conditions. By integrating high-resolution spatial data with scenario-based modeling, it provides a transferable framework for implementing SLM practices in erosion-prone regions. The findings emphasize the necessity of adaptive management to address soil erosion and inform sustainable land-use planning globally. Graphical Abstract This Graphical Abstract visually summarizes the study’s key findings on the role of Sustainable Land Management (SLM) in mitigating soil erosion and sediment export. The diagram outlines the methodology and key variables influencing erosion processes, using the Sediment Delivery Ratio (SDR) model to assess the impacts of SLM interventions. The left section of the figure highlights the study area in Morocco, covering 102 sub-basins across 12 hydrological basins, where erosion processes were analyzed. It illustrates a comparison between the current scenario and an SLM scenario, where agricultural lands experience a 25% increase in soil organic matter. In the central section, key environmental factors—land use, rainfall, soil erodibility (K Factor), and slope—are depicted as primary variables influencing sediment dynamics. These factors interact with SDR outputs, affecting soil loss, sediment export, and deposition patterns. The SDR model application (bottom-left) integrates these variables to simulate erosion processes, generating spatial outputs such as RUSLE, sediment export, sediment deposition, avoided export, and avoided erosion. The results demonstrate the differences between the current scenario and the SLM intervention, emphasizing the potential of improved land management practices. On the right side, statistical analysis results highlight the relationships between precipitation, slope, soil erodibility, and sediment transport across the study basins. The conclusion box presents the main findings: A 25% increase in soil organic matter reduces sediment loss by > 1 ton/ha annually. Scenario-based modeling provides a transferable framework for SLM applications. SLM significantly decreases soil erosion and sediment export, enhancing climate resilience. This graphical representation provides a clear and concise visual synthesis of the study, facilitating a better understanding of erosion processes and SLM effectiveness in mitigating land degradation.