【Aging, safety net and fiscal crisis in Japan】No.251: The extent of flood damage in 2020 is likely to be the greatest ever

July 2020 has seen the heaviest rain that Japan has ever experienced, causing much damage across the country. In each region, rivers that used to be clear streams and popular tourist attractions until June have been flooded; this has not only affected housing but also destroyed other infrastructure, such as nursing facilities, medical facilities, roads, and bridges. According to a report issued on July 11th by the Ministry of Land, Infrastructure, Transport, and Tourism, 101 rivers have been flooded in 12 prefectures, and 1,550 hectares of land have been damaged. In the past, volunteers from all over the country would gather to contribute to the recovery work. However, because of the risk of coronavirus disease, the disaster area is reluctant to accept volunteers this year.

Japan is a country that experiences a lot of flood damage because of the typhoons occurring every summer. Figure 1 compares the extent of damage between a flood and a fire. Looking at the extent of damage in 2018, the fire cost JPY 80 billion (US$ 0.74 billion), whereas the flood cost JPY 1,405 billion (US$ 13 billion). As such, the negative impact of flood damage on the economy is far greater than that of fire. The extent of flood damage fluctuates greatly because the number of typhoons that land on the Japanese archipelago varies from year to year (Figure 2). The highest flood damage to date has been JPY 2,018 billion (US$ 18.7 billion) in 2004, when 10 typhoons landed in Japan. Based on this, it is shocking that the flood in July was not caused by a typhoon. Depending on the number of typhoons landing in Japan, the extent of flood damage in 2020 is likely to exceed the record high in 2004.

Figure 1 Flood damage and fire damage

*Please click the table image to find the original size image.
Source: Ministry of Land, Infrastructure, Transport, and Tourism / Ministry of Internal Affairs and Communications

Figure 2 Typhoons

*Please click the table image to find the original size image.
Source: Japan Meteorological Agency