Evidence Based Landslide Hazard Mapping in Purworejo using Information Value Model Approach

Abstract

Purworejo District, which is located in Central Java, Indonesia, is prone to landslides. These are a natural hazard that often occur in mountainous areas, so landslide hazard analysis is needed to develop mitigation strategies. This paper elaborates on the use of an evidence-based statistical approach using the Information Value Model (IVM) to conduct landslide hazard mapping. The parameters of slope, aspect, elevation, rainfall, NDVI, distance from rivers, distance from the road network, and distance from faults were employed for the analysis, which was conducted based on a raster data environment, since the pixel is the most appropriate means to represent continuous data. Landslide evidence data were collected by combining secondary data and interpreting satellite imagery to identify old landslides. The IVM was successfully calculated by combining factors related to disposition to landslides and data on 19 landslide occurrences. The results helped produce a landslide susceptibility map for the northern and eastern parts of Purworejo District.

Mapping Landslide Susceptibility Areas Using GIS Analysis in Cilawu Sub-district, Garut, West Java

“…Slope was chosen as one of the key factors for mapping landslide susceptibility because it is related to shear pressure inside the soil (Hong et al, 2019). With a dominant slope of 15-30%, this sub-district is vulnerable to soil movement because the land flow velocity is high and able to move soil material to a lower area due to gravity resulting in a more significant opportunity for soil movement to experience landslides (Sudaryatno et al, 2019). Based on the distribution of susceptibility levels on the landslide susceptibility map and the previous graph of the area of susceptibility per village, the widest very high and high susceptibility areas are in Sukamurni Village with an area of 110.37 Ha and 1395.36 Ha, respectively.…”