Study of climate and land use change as considerations for sustainable agricultural land in the Saddang watershed

Abstract

Saddang Watershed is one of the watersheds in South Sulawesi, which supplies water for agricultural land. However, the current challenge is climate change and land-use change that affect the sustainability of agricultural land. As a response, land analysis in the Saddang watershed needed starting with climate change analysis with rainfall projected in 2040, continued by land-use change analysis, land condition based on erosion rates, and sustainable agricultural land analysis directions. Rainfall projection using CSIRO general circulation model (GCM) CSIRO Mk3-6-0 climate model. Landuse change analysis using remote sensing methods with Landsat Imagery in 2000 and 2020. Landuse calculated as land condition based on erosion rate with USLE (Universal Soil Loss Equation) methods. Land conditions are a necessary consideration to formulate directions for sustainable agricultural land. The results of the rainfall projection in 2040 showed an increase in rainfall. It has an impact on land conditions. The rainfall increase occurs during the rainy season (October to January), while the rainfall decrease occurs during the dry season (July to September). Climate change was changed farmers’ cropping patterns, which usually started in October. As a response, it is necessary to increase the farmers’ adaptation by selecting plant types and mitigation activities by making reservoirs a source of water and preparing to enter the dry season. Land-use change showed a significant increase in agricultural lands, such as rice fields, agricultural and plantation land. The increase of agricultural land was converted from dry land to mixed agricultural brushwood. Most of the land conditions from dry land agricultural and dryland agricultural mixed brushwood have a high erosion level. High erosion level caused by slope conditions (rather steep, steep and very steep) and high rainfall also affects. Preserving agricultural land can be carried out through vegetative techniques. Vegetative techniques are helpful in reduced erosion levels because they didn’t require a large amount of money. Vegetative techniques applied in the Saddang watershed are agroforestry, alley cropping, and strip planting along the contour.