Modeling the impact of land cover change on erosion dynamics in the Matting River catchment, Saddang Watershed

This study aims to evaluate the impact of land cover changes on erosion rates in the Matting River catchment, part of the Saddang watershed in north Toraja regency, and to project future conditions up to 2030. The research follows a remote sensing and modeling approach combining MOLUSCE for land cover change projection and SWAT for erosion simulation. Satellite imagery for 2011 and 2020 were classified and validated using confusion matrices, while land cover for 2030 was projected. These data were used to simulate hydrological and erosion dynamics through the SWAT model. The main findings revealed a significant increase in agricultural land (from 399 ha in 2011 to 519 ha in 2030) and a decline in rice fields and grasslands. This shift directly influenced erosion patterns: total erosion was 1.9 million tons/year in 2011 and declined progressively to 0.5 million tons/year by 2030. Forested and shrub-covered areas contributed the least to erosion, while agricultural lands contributed the most. The projected results indicated that the area is moving towards lower erosion hazard classes, supported by improved land cover and potential conservation actions. This research is limited by the assumption of consistent climatic input and fixed land management practices during the projection period. However, it provides practical value in guiding future land use and conservation planning. The originality of this study lies in its integrated approach using MOLUSCE and SWAT for forecasting land cover-driven erosion at the sub-watershed level, contributing to regional-scale watershed management strategies.