Specific condition in slope failures happening sporadically and the setting of critical line

Abstract

For the non-structural measures of erosion control works, the improvement of accuracy in speculating slope failure generated in a concentrated manner has been advanced with improved technology in setting the critical line (CL) . However, speculating method for the slope failure generated within the safety zone of the set CL, known as the sediment-related disaster sporadically generated, still shows little improvement. Therefore, disability of warnings and evacuation was assumed to be the key in disaster prevention. In this study, we worked on the specifications of the slope failures sporadically generated, using the rough sets, at the southern part of Shimonoseki City where danger of slope failure is relatively high comparing with other regions in Japan. In addition, the setting of CL for region with more possible warnings and evacuation information was attempted not only on concentrated occurrence but also on the one sporadically generated in a specific region.