2:15 PM - 2:30 PM
[HDS08-15] Development of geological information for slope disaster risk assessment in Geological Survey of Japan.
Keywords:slope disaster, geological information, susceptibility map, Northern part of Kyushu
In Japan, many slope hazards occur every year, causing damage to homes, infrastructure and other facilities below the slopes. Although efforts have been made to identify hazardous areas, the interpretation of geological conditions as a predisposing factor for slope hazards is difficult due to complex factors such as strata, rock types and ages, alteration and weathering, and is limited to case studies.
We have developed geological information that contributes to slope hazard risk assessment and created a susceptibility map from the geological information. For this purpose, we collected and analysed geological information, and analysed geophysical and satellite data.
The geological information was divided into wide-area and priority areas. The wide-area information is intended to provide an overview of the entire Kyushu region. Detailed geological information of the priority areas expected to be used for disaster management planning and countermeasures. Geological information on priority areas was developed in Nagasaki and parts of Kumamoto Prefectures.
A susceptibility map was prepared using the re-analysed 1:200 000 seamless geological map and various topographic elements as input data for the preparation of wide-area information.
On the other hand, in the Nagasaki area, one of the priority areas, a strike and dip map was prepared to understand the flow-board catchment. Seamless 1:50,000 geological maps and structured legends were also prepared. In the Kumamoto area, a layer thickness map of fragile volcanic ash was prepared. Aeromagnetic surveys were also conducted to map the distribution of geological features that have undergone hydrothermal alteration and become clayey.
An overview of the development of such geological information is presented.
We have developed geological information that contributes to slope hazard risk assessment and created a susceptibility map from the geological information. For this purpose, we collected and analysed geological information, and analysed geophysical and satellite data.
The geological information was divided into wide-area and priority areas. The wide-area information is intended to provide an overview of the entire Kyushu region. Detailed geological information of the priority areas expected to be used for disaster management planning and countermeasures. Geological information on priority areas was developed in Nagasaki and parts of Kumamoto Prefectures.
A susceptibility map was prepared using the re-analysed 1:200 000 seamless geological map and various topographic elements as input data for the preparation of wide-area information.
On the other hand, in the Nagasaki area, one of the priority areas, a strike and dip map was prepared to understand the flow-board catchment. Seamless 1:50,000 geological maps and structured legends were also prepared. In the Kumamoto area, a layer thickness map of fragile volcanic ash was prepared. Aeromagnetic surveys were also conducted to map the distribution of geological features that have undergone hydrothermal alteration and become clayey.
An overview of the development of such geological information is presented.