Land Carrying Capacity Assessment for Harmonizing Environmental and Anthropogenic Pressures in the Tiworo Watershed

Abstract

The Tiworo Watershed on Muna Island, Southeast Sulawesi, is experiencing increasing ecological and anthropogenic pressure threatening ecosystem sustainability. Land cover change has intensified surface runoff and affected downstream and coastal ecosystems. This study assesses land carrying capacity in the Tiworo Watershed based on biophysical characteristics to support management. The assessment applies three key indicators—Percentage of Critical Land (PCL), Percentage of Vegetation Cover (PVC), and Erosion Index (EI) in accordance with Minister of Forestry Regulation No. P.61/Menhut-II/2014. A spatial analysis approach using Geographic Information Systems (GIS) was employed. Secondary data was obtained from satellite imagery and relevant agencies, including watershed boundaries, land use and land cover, critical land maps, rainfall, soil type, and slope. Soil erosion was estimated to be using the Universal Soil Loss Equation (USLE), with tolerable erosion (ETOL) values from previous studies. Land carrying capacity was calculated using a regulation-based weighted scoring method, in which PCL, PVC, and EI were weighted at 50%, 25%, and 25%, respectively, to generate a composite score. The results show that 65.4% of the watershed is classified as potentially critical land, with 8.14% categorized as critical to very critical. Vegetation cover remains high at 89.57%, while the erosion index reached 13.65, exceeding tolerable limits across more than half the watershed. The composite land carrying capacity score of 87.5 places the watershed in a good sustainability category despite localized degradation. These findings highlight the need to control land conversion, strengthen soil and water conservation, rehabilitate degraded land, and integrate land carrying capacity into spatial planning.

Keywords: Carrying Capacity, Land Sustainability, Tiworo Watershed, Watershed Management.