| When a large-scale collapse occurs by heavy rain or earthquakes, a natural dam may be formed. It becomes important to know the timing of occurrence of debris flow caused by overflow or erosion of the natural dam for early-warning and evacuation. An Aerial Placeable Floating water stage gauge was developed in 2008. It is a device which has resolved the problems of the power source in a mountainous region, difficulty of installation, etc. Multiple large-scale natural dams were created in Kii Peninsula by the typhoon Talas in September 2011. Devices as above were dropped onto dammed-up lakes of natural dams, and the water level of the natural dams were monitored. The observation results of above and the future tasks concerning observation are organized in this document. |
