# Utilization of ICT as a Digital Infrastructure Concerning Disaster Countermeasures in Japan
## 6 Utilization Potential of Social Media Mapping as a Digital Infrastructure  
[PERSON] et al. (2018, 2019) [8; 9] integrated multiple systems including social media and Web-GIS to develop a spatiotemporal information system. The following will introduce case examples related to the function of social media mapping. The spatiotemporal information system is categorized into education and tourism depending on the intended use, and the function of social media mapping is part of the tourism system. By using the function, submitted information with location information from all over the world is gathered from 5 social media platforms (Instagram, Twitter, Flickr, YouTube and Webcams), and consolidated to be displayed on a two-dimensional digital map of Web-GIS. Though disaster countermeasures are not the original purpose of the system, much disaster-related information could be gathered during the heavy-rain disaster in Western Japan in 2018. Moreover, the heavy-rain disaster in Western Japan in 2018 was caused by Typhoon Prapriroon and heavy rainfall during the rainy season resulting in great damage in 15 prefectures in Western Japan.  
Figure 6 shows a screen displaying the Setouchi Region using the function of social media mapping. The number of submissions during the heavy-rain disaster in Western Japan in 2018 rapidly increased, and Figure 6 reveals that this number was especially high in the worst-hit areas. Figure 7 shows the submitted information in Mabi-cho, Kurashiki City, Okayama Prefecture, Figures 8 and 9 respectively show those of Fukuyama City, Hiroshima Prefecture and Ozu City, Ehime Prefecture. As shown in Figure 7, Mabi-cho is on the outskirts of Kurashiki City and suffered enormous damage due to the floods leading to videos of the damage situation submitted on YouTube. There are many reservoirs distributed throughout Western Japan, and when one of these in Fukuyama City collapsed due to the heavy rain, a video of the situation was submitted on YouTube as shown in Figure 8. In central Ozu City, flood damages caused by the flooding of the Hijikawa River have frequently occurred in the past, and images of the damage situation from the heavy-rain disaster in Western Japan in 2018 were submitted on Instagram as shown in Figure 9.  
Figure 6: A screen of the Setouchi Region displayed using the function of social media mapping.  
It has become evident that disaster-related information can be efficiently gathered during disasters by not only consolidating the submissions with location information to the digital map but also by searching for submissions using the search function of each social media platform, with the function  
Figure 8: Submissions on YouTube concerning Fukuyama City, Hiroshima Prefecture.  
Figure 7: Submissions on YouTube concerning Mabi-cho, Kurashiki City, Okayama Prefecture.  
Figure 9: Submissions on Instagram concerning Ozu City, Ehime Prefecture.  
of social media mapping. Additionally, it was also found that the location information attached to submissions could become \"life-saving information\" during a disaster.  
Utilization Potential of Twitter as a Digital Infrastructure Based on the Cases of the Heavy-Rain Disaster in Western Japan in 2018