Jabungan Village is a sub-district in Banyumanik District, Semarang City. This area is surrounded by beautiful hills and has the potential to be developed as a tourist spot in the city of Semarang. But behind the beauty of the hills in Jabungan, there is a potential disaster that threatens the area. According to Central Java disaster data based on BNPB (2021), topography, climate, geology, hydrology and land use conditions determine potential danger vulnerability to a natural disaster. From this data, the most common natural disasters in Central Java are landslides followed by floods.
This is the background for the Undip Geological Engineering team to carry out Community Service activities. The first step taken is to coordinate with service partners to find out the needs and problems faced. Mapping was carried out on three types of disasters, namely landslides, floods and drought. These three are the disasters that occur most frequently in Jabungan Subdistrict, based on information from the Subdistrict Head in 2024. Activities are carried out using field observation methods to collect geological data and geospatial analysis to compile disaster prone maps. Activities have been carried out in the period February – June 2024.
The geomorphological location of the dedication itself is a structural hill with morphological characteristics of a light-medium cut texture and a fluvial plain of a river system with a dendritic drainage pattern. Geological observations found that the lithology type was dominated by mudstone with a bright gray appearance with a low-high level of weathering. Another lithology found was volcanic breccia with a bright gray appearance with low-high weathering levels. Climatologically, Jabungan Village, Banyumanik District has a rainfall level of around 600 mm/year (Semarang City Government, 2024) and the number of days with the highest amount of rainfall is 60 days. This high rainfall is one of the factors that triggers ground movement, in this case landslides. Meanwhile, in flood disasters, high rainfall is also one of the main causes. Jabungan sub-district has an area of 226.5 ha with a population of 4,293 people. The land use at the service location consists of medium density residential areas, including new housing complex development areas, rice fields, fields/gardens, conservation forests, and other dry land. Based on lithological parameters, slope, rainfall and land use, geospatial analysis is calculated using a raster calculator in ArcMap software.
Based on the analysis that has been carried out, three types of disaster risk maps have been produced which are needed for the development of the Jabungan Village area. The potential for landslides in this area shows an index of low to high vulnerability. It is necessary to be aware of areas that are prone to very prone to landslides, which are quite widespread and comprehensive in Jabungan Village. The southeastern area of the service location has a moderate to high flood vulnerability index. Meanwhile, areas with higher slopes and flowed by smaller rivers still need to be alert to the potential for flash floods. Based on geospatial analysis, the potential for drought disasters in Jabungan Village is low to moderate. Land uses that still have lots of green areas such as forests and fields are still considered safe in storing water reserves at service locations.
The service team has prepared information media that can be accessed by the public, namely an information poster on potential disaster vulnerabilities in Jabungan Village. This poster, which was prepared by the service team from the Department of Geological Engineering, Faculty of Engineering, Diponegoro University, was well received by the head and staff of Jabungan Village. The service team appealed to these agencies to pay attention to areas with a high disaster vulnerability index. This service activity is one of the steps in disaster mitigation. Mitigation involves universities contributing knowledge regarding the characteristics and mapping of disaster hazards. Furthermore, local agencies and governments are embracing the community to understand and be aware of disasters around where they live. This understanding and awareness is one of the initial capital in disaster preparedness, so that the damage it causes can be prevented or minimized.
