Photo/Illutration The Mogamigawa river overflows on July 26, flooding homes in Tozawa, Yamagata Prefecture. (Tatsuya Shimada)

Global warming increased rainfall by more than 20 percent during the devastating heavy rains that struck Yamagata and Akita prefectures in July, according to the science ministry and the Japan Meteorological Agency.

Researchers from the JMA’s Meteorological Research Institute and Kyoto University employed an event attribution analysis technique to assess the impact of climate change on the 48 hours of rainfall leading up to 9 a.m. on July 26.

The rainfall in Yamagata Prefecture and surrounding areas was more than a fifth heavier than without global warming, according to the findings released on Sept. 2.

Some areas within the prefecture recorded more than 400 millimeters of rainfall in the 48-hour period. The study suggests that climate change contributed to an additional 100 mm of rainfall in certain areas.

“Even in the Tohoku region and Hokkaido, which have historically experienced relatively low rainfall, the risk of extreme downpours is increasing due to climate change,” said Tetsuya Takemi, a professor of meteorology at Kyoto University’s Disaster Prevention Research Institute.

“We need to both strengthen our preparations for heavy rainfall and take urgent action to mitigate climate change,” he added.

The torrential downpours, which occurred from July 24 to 26, were driven by an active seasonal rain front and the formation of a linear rainband.

The heavy rain caused widespread damage, including breached embankments, landslides and flooding of homes, causing three fatalities in Yamagata Prefecture.

Related News