Practical use of the number of telephone report for estimating heavy rainfall disaster

Abstract

During heavy rainfall disaster, one of the important activities of municipalities is to understand the disaster risk in the region, and if required, is to call attention to the residents. Municipality acquires various information, and they must determine the correspondence based thereon. However, telephone reports from residents increase as the situation progresses, it's said to be one of the factors to inhibits the understanding of the critical information, and delay the decision. From a different viewpoint, the telephone report can be regarded as the disaster information with a property of "number is increased as the situation progresses". By utilizing this property, the number of telephone report is possible to be an effective information for understanding the disaster risk in the region.

Our study aim to clarify that changes in number of telephone reports during heavy rainfall disaster is related to transition of precipitation. In addition, we aim to clarify that the place of damage is related to the location of the telephone reports.

First, we revealed that many of the damage has occurred near of the location of the telephone report. After that, we subdivided the region, and revealed that heavy rain has led an increase in the number of telephone report and occurrence of damage.

Consequently, aggregating the number of telephone report had been shown to be an useful measure for estimating heavy rainfall disaster.