Actual state of action taken by residents when sediment disasters occurred in Northern Kyushu Region in July 2012

Abstract

Many debris flows and slope failures occurred concentratively in the Northern Kyushu Region in July 2012, which led the damage of 25 people dead or missing in the Aso district in Kumamoto Prefecture. Although these disasters are calamity, but they provide useful information for prefectural governments to establish warning and evacuation system for sediment-related disasters,such as debris flow or slope failure prone area. We held an interview to the residents of the Aso city which affected landslide disaster to obtain information about disaster characteristics and how they evacuated on September 20-21, 2012.
There found several causes which make their evacuation difficult as a result.
－Danger by intensive downpour and thunderbolt.
－Difficulty to watch out surrounding situation through darkness and rain.
－Overflow of muddy water to the evacuation route and debris as obstruction.
From the actual condition of evacuation in this time, four important points are suggested to improve warning and evacuation system in future.
－Improvement of accuracy to predict precipitation amount which promotes prior evacuation.
－The set-up of the timing of evacuation in consideration of a regional peculiarity.
－Development of evacuation for primary refuge and secondary to help safe evacuation.
－Improve laws/regulations of local land-use for improvement of evacuation routes.