Review of restoration processes for damaged social infrastructures in Japan and building a performance indicator for designing disaster mitigation policy

摘要

Japan has experienced many large-scale natural disasters such as earthquakes, typhoons accompanied by heavy rain and landslides, and tornadoes. Based on the data of damage caused by four recent major earthquakes in Japan (the Hanshin-Awaji, Niigata-Chubu, Great East Japan, and Kumamoto earthquakes), we investigate the restoration processes of public utilities for major social infrastructure including electricity, gas, water, and communication lines by comparing the differences regarding the speed and trends. The results of various statistical data analyses and mathematical modelling analyses are used to make policy suggestions. In addition, we attempt to build performance indicators (PIs) for water supply businesses to measure the robustness of the water supply network system. Using actual data related to the water supply in Japan, we illustrate the numerical results for the PIs, which can be used to design natural disaster mitigation policies.