Disaster-Affected Area Estimation Method with Open Multispectral-Image Data Analysis for Multidimensional World Map System

In this paper, we propose a "disaster-affected area estimation method”, which is a simple and low-cost disaster-impact survey and risk assessment method using satellite multispectral images and GIS data for collecting disaster information in a wide area and in real-time. One of the features of our method is in the low-cost and low-technical barriers to implementation, as it utilizes open data satellite multispectral imagery to estimate the size of disaster-affected area with relatively high accuracy using an inexpensive and uncomplicated estimation method. This feature makes the method widely applicable to Least Developed Countries and small local government units. The method is particularly effective in disaster countermeasures, such as rapid confirmation of the disaster situation in wide-area disasters. In this paper, the basic concept and the implementation method of our disaster-affected area estimation is presented. By applying the method to several cases of landslide disaster in Japan, it is discussed that the method can detect and estimate the size of disaster-affected area with a certain level of accuracy. In addition, the feasibility of the method for the automation of disaster surveys is demonstrated, and the issues for its future implementation are identified.