# Utilization of ICT as a Digital Infrastructure Concerning Disaster Countermeasures in Japan
## 4 The Significance of ICT as a Digital Infrastructure Concerning Disaster Countermeasures  
### The Various Information Communication Methods Used during Disasters  
According to [PERSON] (2017) [29], various initiatives have been taken to minimize information vacuums as the great East Japan earthquake (2011) caused immense damage to a digital infrastructure, and a broad area was left blank in terms of information communication immediately after the earthquake. Due to the widespread and immense damage caused, a new type of media such as social media,  
Figure 1: Penetration rate of the PCs, internet, and mobile phones (1993–2012). Note—created based on the Consumer Behavior Forecasting Survey 2014 [27].  
where individuals can send detailed information without the limitations of mass media, was utilized. In particular, individuals on social media can send information from both PCs and mobile information terminals enabling the damage situation to be widely communicated before mass media can enter the damaged area. This is made possible by the spread of various social media in which individuals can send and receive information in multiple forms by combining images, videos, voice recordings in addition to texts. In this way, social media has become part of the disaster information sharing system (L-Alert), and has fulfilled a big role in the diversification and layering of information communication methods. However, various issues have emerged regarding the utilization of the internet during disasters such as the massive amount of communication traffic, communication blackouts, as well as measures to deal with false information and chain emails. This is one of the biggest differences to when the great Hanshin-Awaji earthquake (1995) occurred.  
At the time of the great Hanshin-Awaji earthquake, telephones and transportation were disrupted in the damaged area as well as its surrounding areas creating a donut-shaped information vacuum in the center of the damaged area. Additionally, information was one-sidedly provided through mass media such as newspapers, magazines, radio and television. Furthermore, the information reported immediately after the earthquake was mainly provided through radio and television, while the internet was mainly used after the rescue and relief stage. However, the usefulness of GIS has come to be positively recognized after the great Hanshin-Awaji earthquake. Specifically, the database compilation of the damage situation was created using GIS, and this was used to support restoration plans in the affected areas.  
In the heavy-rain disaster in Western Japan in 2018, various disaster information was provided by national institutions and private corporations related to surveys and GIS using digital maps, and satellite images and aerial photos. Additionally, various entities cooperated in consolidating activities concerning disaster countermeasures using ICT including Web-GIS. Because ICT was effectively used in such disaster countermeasures, a wide variety of information was transmitted and updated in real-time, and the voluntary provision of information by various entities or industry-academia-government collaborations increased. Furthermore, these various disaster countermeasures were widely made known through both mass media and social media.