Disaster mitigation on lands affected by landslides in Banjarnegara Regency

Landslide mitigation on potentially-affected lands is one of the crucial efforts in Banjarnegara Regency. Such effort, however, must comply with the existing environmental and land use conditions. This research aimed to determine the landslide susceptibility level and landslide mitigation on the affected land. A descriptive quantitative method was used to determine landslide susceptibility, and a survey method was used to determine its condition. Landslide susceptibility was examined using an overlay analysis of the major factors: slope, texture fault, regolith, and geology. The analysis results show that the levels of landslide susceptibility of the research location consisted of: not prone (19.21%), slightly prone (4.95%), moderate (6.92%), prone (29.20%), and very prone (39.72%). It also predicted that 335,940 people (36.80%) lived in highly and very-highly vulnerable areas. Based on the results, mitigation is targeted on three groups of land, including water bodies (269.57 ha), vegetated area (69,946.98 ha), and non-vegetated area (3,506.25 ha). Both physical and social mitigation actions are thus required. Physical mitigation includes slope protection (terracing, vetiver system, slope-protection structures, ground fractures covering), water management (manual horizontal drainage, drainage channel), vegetation management (multi-stratum canopy, root morphology, and plant biomass), whereas social mitigation involves community management by promoting public awareness and vigilance against disasters, and the active role of both community and stakeholders.