土石流による被災集落の復興実態と被災者の精神的被害額の試算

摘要

A debris flow disaster can cause considerable damage in the stricken area, which can affect the people dwelling there. We investigated changes in communities each year after a disaster. We also proposed a method for calculating the monetary cost of living as a refugee, which causes long-lasting mental trauma. The results were as follows ：(1)after a debris flow disaster, the community does not recover to its original situation, and people are forced to out-migrate to neighboring regions or public housing, as per the examples of Harihara, in Kagoshima Prefecture, and Minamata, in Kumamoto Prefecture, Japan. It became apparent that it is difficult for single elderly persons to rebuild residential housing ； (2) the recovery period from a debris flow disaster in the Minamata area was estimated to be around 10 years ； (3) when the method was applied to a sediment-related disaster hazard area in Aso， in Kumamoto Prefecture, the total cost of mental damage was estimated to be 221.2 million yen ； and (4) when the method was applied to the entire basin, which contains 68 streams that pose a danger of mud and debris flows, the monetary cost of living as a refugee, and the cost-benefit ratio of the long-lasting mental trauma, increased by 0.1.%一般に土石流による人的被害が生じるような大規模な災害が発生した場合，土砂災害の概要を記載した速報的な報告（例えば，海堀ら，2014;権田ら，2015)，土石流に伴う土砂移動現象に着目した報告（例えば，平松ら，2014)，土砂災害発生時の住民や行政の行動に着目した報告（例えば，菊井ら，2008)が,砂防学会誌をはじめとする複数の学会誌において発表されている。