Mapping Landform and Landslide Susceptibility Using Remote Sensing, GIS and Field Observation in the Southern Cross Road, Malang Regency, East Java, Indonesia

Abstract

There has been an increasing trend of land area being brought under human’s use over time. This situation has led the community to carry out land-use development activities in landslide hazard-prone areas. The use of land can have a positive impact by increasing economic conditions, but it can have negative impacts on the environment. Therefore, this study aimed to identify the landslide hazard, focusing on the development of a landform map to reduce the risk of landslide disaster in JLS, Malang Regency. The integration of remote sensing and geographic information systems, as well as field observation, were used to create a landform map and a landslide susceptibility map. Using the geomorphological approach as a basic concept in landform mapping, the morphology, morphogenesis, and morphoarrangement conditions were obtained from the remote sensing data, GIS, and field observation, while morphochronological information was obtained from a geological map. The landslide susceptibility map was prepared using 11 landslide conditioning factors by employing the index of entropy method. Thirty-nine landform units were successfully mapped into four landslide susceptibility classes. The results showed that the study area is dominated by a high level of landslide susceptibility with a majority of moderate to strongly eroded hill morphology. It also reaffirms that landform mapping is a reliable method by which to investigate landslide susceptibility in JLS, Malang Regency.

Mapping Risk Level Based on Peak Ground Acceleration (PGA) and Earthquake Intensity Using Multievent Earthquake Data in Malang Regency, East Java, Indonesia

“…It was found that Malang Regency had a PGA value of 0.358 gal (Kumala, 2016). Based on remote sensing, GIS, and field observations, this is different from this research because the subject of disaster mitigation is different, namely for landslide disaster mitigation (Bachri et al, 2021). The results of this study were not detailed.…”

“…This research was conducted in Malang Regency with coordinates 7.22° -9.52° S and 112.12° -112.60° E (Figure 2). The physiographical conditions of Malang (Figure 2) are highly variable and dominated by undulating and hilly soil that is prone to landslides (Bachri et al, 2021). Then, Malang was divided into several parts with a grid size of 0.025º x 0.025º to make it easier to read the results of the calculation of the PGA value and the intensity of the earthquake in each regency.…”

“…Malang is located in the south of East Java. It is a high earthquake risk area (Bachri et al, 2021). It is caused by the tectonic activities from some faults around it, including the Grindulu fault in Pacitan and the Klangon fault in Madiun (Lestari et al, 2019;Yusvinda et al, 2021).…”

“…Based on the description of tectonic conditions and the data on earthquake studies in the Malang district, earthquake disaster mitigation is urgently needed in order to reduce the impact caused by earthquakes. There are several methods used in earthquake disaster mitigation, including the study of the seismicity of an area, mapping of earthquake vulnerability based on geographic information systems, and regional and city spatial planning in accordance with earthquake hazard studies (Ashadi & Kaka, 2019;Bachri et al, 2021). Regional and city spatial planning in accordance with an earthquake hazard study used an assessment method based on the Peak Ground of Acceleration (PGA) parameters and earthquake intensity (Yao et al, 2020).…”

Coping Mechanism in the Face of Landslide Hazard in East Java Indonesia

“…Furthermore, the rainfall intensity at the average rainfall is ranging from 0 mm to 602 mm (BPS of Malang Regency, 2020). Based on the landform configuration, the study area is dominated by hilly and strong erosion processes (Bachri et al, 2021). Detail of landform identification within the study area can be seen in below Table 2.…”