Mitigasi Dampak Perubahan Tutupan Lahan Terhadap Potensi Erosi dan Sedimentasi di Daerah Aliran Sungai (DAS) Pawan, Kalimantan Barat

Abstract

The increase of land conversion and anthropogenic pressures in the Pawan Watershed potentially reduce environmental quality and disrupt the hydrological balance of the region. This study aims to analyse the dynamics of land cover change, the potential for erosion and sedimentation in the Pawan Watershed, West Kalimantan, during the period 1990–2023 using Geographic Information System (GIS) analysis and the Universal Soil Loss Equation (USLE) model. The results indicate a significant decrease in secondary forest area from 464,572.67 ha to 393,711.84 ha, accompanied by a 12.41-fold increase in plantation areas compared to their extent in 1990. These changes were primarily driven by the conversion of vegetated land into plantations, mining areas, and settlements. Erosion estimation using the USLE model revealed an increase in erosion rates from 656.38 tons/ha/year to 890.00 tons/ha/year, with sediment loads increasing by approximately 35.6%. These findings indicate intensify land degradation, sedimentation, and flood risk within the Pawan Watershed during the study period. The study highlights the importance of sustainable watershed management through forest rehabilitation, soil and water conservation, and adaptive land-use planning and control to maintain hydrological balance and ensure the sustainability of natural resources in the Pawan Watershed.