# Utilization of ICT as a Digital Infrastructure Concerning Disaster Countermeasures in Japan
## 6 Utilization Potential of Social Media Mapping as a Digital Infrastructure
### Utilization of Twitter during the Heavy-Rain Disaster in Western Japan in 2018
This was to prevent the tweets of those still waiting to be rescued from being buried among other tweets, and protect personal information such as an individual's address. Twitter has implemented similar support activities during other disasters such as the great East Japan earthquake in 2011 in addition to the Typhoon Krosa and Typhoon Hagibis in 2019. A tweet related to the elderly person rescued by the Self-Defense Forces (SDF) was submitted during the heavy-rain disaster in Western Japan in 2018. This tweet contained appreciation to the SDF who were able to rescue the elderly person after her family members living away from the area submitted a rescue request tweet on her behalf. Many similar tweets were seen after the heavy-rain disaster in Western Japan in 2018. Utilization Potential of Twitter as a Familiar Digital Infrastructure Concerning Disaster Countermeasures  
Based on the utilization of Twitter in the heavy-rain disaster in Western Japan in 2018 described in this section, the following suggests the utilization potential of Twitter as a familiar digital infrastructure \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{2}{c}{**Hashtags during and Immediately after the Disaster**} \\ \hline \hline \multirow{6}{*}{Specific locations of the affected areas} & \#affectedareasoftheheavyraindisasterin westernjapanin2018 \\  & \#(affectedlocalgovernment(prefecture/city/town)) \\  & \#Mabicho(KurashikiCity) \#(specific areas or rivers) \\  & \#(specificolications(schools and other facilities that are designated as \\  & evacuation centers and hospitals)) \\ Name of the specific locations within Mabi-cho & \#147@IsujitAMBicho \#YataMabicho \#KawataMabicho \#OkadaMabicho (Including tweets without hashtags but contain requests to be retweeted) \\ Information communication & \#pleaseretweet \#retweet \#RT \#PleaseRT \#warmings \\  & \#currentstiuationnotreported \\ \hline \multicolumn{2}{c}{**Hashtags from Immediately after the Disaster**} \\ \hline \hline \multirow{3}{*}{Name of the disaster} & \#Heavyraindisaster|uly2018 \\  & \#disasterfrom2018 JapanFoods \#2018 JapanFoods \#Westernjapanisaster \#heavyraind \\  & \#(disaster)restoration \#(disaster)recovery \#medicalcare \#DMAT \\  & \#watersupply \#(disaster)volunteer \#volunteerswanted \#Ievacationsite \#(specificevacationsite) \#(disaster)support \#reliefsupplies(specific \\ Support & \#wewillsendsupplies \#bath \#shower \#onsen@disastervictims \\  & \#affectedareas \#Letthisisearchtodissastervictims \#helpingeachother \\  & \#SDF(dispatched) \\ Encouragement & \#StaystrongWestJapan \#Staystrong(affected local government \\  & (city/town)) \#StaystrongMabicho \#Wecanbeatheheavyrain \\ Donation and contributions & \#2018 JapanFoodsidsonstarestrostationsupportfund \\  & \#tremendouscatastrophe \#designatedtrendouscatastrophe \#designatedprecifieddisaster \\  & \#designatedspecifieddisaster \\  & \#wateroutage \#poveroutage \#heatstroke \#severeat \#infections \\  & \#sterilization \#traffic \#lackofranpower \#lackofwater \#roadclosures \\ Post-disaster issues & \#(disaster)theft \#traffic(affected local government (city/town) \\  & \#donationfatuds \#chainemails \#falsertumors \#Mabheaststroke \\  & \#Mabitrafic \\  & \#lwasrescued \#gratitude \#thankyou \\  & \#pets(in affected areas) \#(pet food) \\ \hline \hline \end{tabular}  
* mark means a hash tag used for SNS such as Twitter, Instagram and Facebook.  
\end{table} 
Table 1: Cont. during disasters. However, consideration is required when setting rules for the utilization of Twitter during disasters as the freedom of utilization outside the affected area should not be restricted. First, the format of the texts for tweets can be created according to its purpose of transmitting information such as evacuation, rescue request and cooperation, support, donation and contribution. In the disasters in recent years, Twitter has encouraged users to use the hashtag \"#rescue\", and instructed them on the specific content of rescue requests leading to some tweets aiding in successful rescues.