Author(s): Koji Asai; Tomohiro Ishii; Takuzo Amano; Hajime Shirozu
Linked Author(s): Koji Asai
Keywords: Slope failure; GIS; Remote sensing; Heavy rain; Optical satellite image
Abstract: Several landslide disasters occurred in Hiroshima due to heavy rainfall of July 2018, and sediment and driftwood caused channel blockage and increased flood damages. Therefore, in order to consider the prevention and mitigation of heavy rain disasters, it is important to consider the effect of the flow into the sediment, driftwood of the river channel. In this study, taking the upstream of Norogawa dam as an example site, various investigations were carried out on slope failures that caused channel blockage. The slope failure region was extracted by optical satellite image, and the correspondence with the dangerous mountain stream with the possibility of the slope failure was evaluated by the least-cost analysis based on the slope of the ground. It was successfully detected the slope failures by using the satellite images before and after disaster. The improvement for the least-cost path analysis is required. However, it is found that this analysis would be useful for the qualitative usage.
Year: 2020