LANDSLIDE VULNERABILITY ANALYSIS OF TOURISM SITES IN THE TOBA CALDERA UNESCO GLOBAL GEOPARK AREA

The geological hazard that frequently occurs at geological tourism sites in North Sumatra is landslides. The most famous geological tourism site in North Sumatra is the Lake Toba Caldera UNESCO Global Geopark (TC UGGp). Several studies and media reports have mentioned that several tourist areas in the Lake Toba region are prone to landslides. One effo rt to reduce disaster risk is to determine the level of landslide vulnerability at sites managed by the TC UGGp. Given that the TC UGGp area has received worldwide attention and significant support from investors, assessing landslide vulnerability based on spatial aspects and field conditions is crucial to improving sustainable management in the TC UGGp area. The objective of this study is to determine the distribution of landslide vulnerability levels at tourist sites in the TC UGGp. Landslide vulnerability mapping in this study was conducted using a spatial model with assessment and weighting methods. The variables used to assess landslide vulnerability include slope gradient, lithology, soil type, and land use. This study f ound that most of the Toba Caldera UNESCO Global Geopark (TC UGGp) area is classified as having very high vulnerability. Several Geosite locations in the TC UGGp area, including Bakkara-Tipang, Tele Efrata, Silahisabungan, Haranggaol, Sipiso-piso, Taman Eden, Hutaginjang, and Sibaganding, are located in areas with high to very high landslide vulnerability. The landslide vulnerability map produced using a spatial model with the natural break classification method shows good accuracy. The results of the landslide vulnerability classification accuracy test show that the overall accuracy value reaches 90.20% a nd the Kappa accuracy reaches 69.02%, indicating that most of the data on the landslide vulnerability classification map corresponds to the actual conditions in the field. Most landslides occur on steep slopes and in areas with evidence of past l and fires. We recommend that Geosite areas with high to very high vulnerability levels implement strict visitor safety standards, adopt infrastructure designs that minimize landslide risk, and strengthen efforts to prevent land burning activities.