Geological structure influence on landslide occurences: Tembalang and Banyumanik sub-districts, Semarang City

Abstract

Tembalang and Banyumanik are two sub-districts in the Semarang City that morphologically have fairly steep hill so they have considerable potential to experience landslides. In addition to fairly steep morphology, some of these areas are traversed by regional geological structures. This study is to investigate the relationship between landslides and the developing geological structures in the study areas. The research methods include the interpretation of the presence of landslides from satellite imagery, interpretation of the existence of structures from the Digital Elevation Model (DEM) map, making a map of landslide susceptibility, and geological mapping to determine the distribution of landslide locations that occur in the study area. The results of the interpretation of landslides through satellite imagery, the interpretation of the structural alignment of the DEM map, and the map of landslide susceptibility, are compared with the distribution of landslides from the field during geological mapping. Mapping results show that there are 6 out of 11 landslides associated with geological structures. The distribution of landslides in the study area is more often found in locations associated with regional geological structures than that the other locations. This shows that the geological structure has an influence on the occurrence of landslide. For this reason, in terms of the development of an area, it is important to conduct an analysis of the geological structure’s occurrence as well as to consider other factors that can cause landslides.