2008 Volume 61 Issue 1 Pages 11-20
Nagasaki is well-known as an area with many sediment-related disasters. On this point of view, installation of erosion control facilities has been pushed forward from the past. However, the installation ratio of the facilities has not always been sufficient because there are too many points. Under the above conditions, for installing the erosion control facilities effectively with limited budget, it is important to consider a priority of an improvement project at each vulnerable spots. Therefore this study performed examination based on an evaluation result by Data Envelope Analysis(DEA) about priority of dangerous spots for sediment-related disasters in Nagasaki. In this study, we used a new factor to evaluate importance of vulnerable spots for sediment-related disasters as well as a factor used in a study example of the past. As a result, a priority that reflects the characteristics of its hazard and importance at each spots can be evaluated. It is recognized that there is a correlation between the evaluated priority and past disaster histories or counter -measure works. This shows that the DEA is proper for priority evaluation and very effective technique for studying erosion control facility improvement projects.