Geomorphology mapping and landslide susceptibility for disaster risk reduction and sustainability environment in the Sub DAS Maspo, Mt. Welirang, East Java, Indonesia

Abstract

Landslides are still problematic for areas with rough surface shapes and high rainfall. Landslides are still causing human life losses, so mitigation efforts for disaster risk reduction must be prioritized. The purpose of this study is geomorphological mapping and landslide hazard mapping as a basis for disaster risk reduction efforts. The method used integrates remote sensing data using geographic information systems. Geomorphology mapping is processed and analyzed using four geomorphological approaches, while for landslide susceptibility maps are analyzed using the Weight of Evidence (WoE) method using existing landslide variables and 17 landslide control factors. The geomorphological mapping results show that in the Maspo sub-watershed, there are 25 landform units based on geomorphological mapping. There are five classes of landslide vulnerability indices, i.e very low index (0.001-0.341) namely 9.38%; low index (0.341-0.471) that is 26.18%; moderate index (0.471-0.584) that is 28.49%; high index (0.584-0.741) that is 23.94% and very high index (0.714-1) that is 12.02%. The accuracy of the landslide hazard map results is 88%, indicating that the landslide hazard map has good accuracy. Dominant landslides of 26.98% and 23.59% occurred in the HS2V1/ME landform, which is the middle slope of the steep hills of the lava eruption of the 2nd Mt. Welirang with moderate geomorphic processes and HS2V1/VSE which is the middle slope of the steep hills of the 2nd eruption of Welirang volcano with the process strong geomorphism. The results of geomorphology mapping and landslide susceptibility can be used as an information base for disaster risk reduction strategies and sustainable environmental management.