Pengaruh Perubahan Tutupan Lahan DAS Bolon terhadap Zonasi Banjir di Permukiman

Abstract

Flood risk assessment is essential for determining flood zonation and formulating effective mitigation strategies. Using a multi-criteria decision support system, this research focuses on assessing the flood risk index in the Bolon watershed. Using Geographic Information System (GIS) as an effective disaster mitigation tool in providing geospatial data. With Cellular Automata-Markov Chain (CA-MC) Method using MOLUSCE Plug in Q GIS to project spatial land change analysis, Analytical Hierarchy Process (AHP) to determine the weight of flood variables, and Weighted Multi-Criteria Analysis (WMCA) for spatial analysis of flood risk. In 2017-2021, land cover changes in the Bolon watershed were significant, an area of 67,55 km² turned into settlements, Deforestation of natural forests also increased, this will affect the hydrological cycle which can increase the risk of flooding. Residential areas at very high flood risk increased from 1,4% (2017) to 2,89% (2021), and are projected to reach 4,74% by 2033, with an average increase of 0,21% per year. This research emphasizes the importance of better land cover management to reduce flood risk in the Bolon watershed as well as strict enforcement of spatial planning and zoning regulations to strengthen supervision and law enforcement against spatial planning violations and land use change, especially in flood-prone areas and water catchment areas.