By Floro Mercene
JAPAN’S record rainfall last month unleashed floods and set off deadly landsides in Western Japan, killing more than 200 people, while forcing millions more to evacuate and leaving dozens missing. Thirteen prefectures on Japan’s mainland received deadly amounts of rain. It was Japan’s worst weather disaster in 36 years. Parts of the region saw as much as four times the average July rainfall during 11 days.
Remnants of Typhoon Prapiroon fed into a seasonal rainy weather front fueled by warm air from the Pacific Ocean. The recent rainfall was unprecedented and disaster experts said torrential rains are becoming more frequent, possibly due to global warming.
Japan, one of the most seismically active places in the world, has stressed the need for earthquake preparedness and enforced regulations to make buildings quake-proof, but it has done less about potential flood disasters. After several smaller disasters in recent years, the land ministry has drafted plans to improve flood control and evacuation plan. The government monitors weather conditions and issues early warnings and advisories, but the nation remains vulnerable to disasters because much of the country outside major cities is mountainous and construction takes place on virtually every bit of usable land. Many houses were built in risky areas before 2005 when the “flood hazard maps” were produced.
The Japan Meteorological Agency introduced a “heavy rain emergency warning”, which was designed to be issued when a heavy rain of an intensity that occurs once in several decades; both the 48-hour precipitation and the soil water index exceeds the level of “once in 50 years” is expected and there is imminent likelihood of a major disaster. Since the introduction in 2013, the emergency warning has been issued 10 times. It is no longer a rarity, but it might be becoming the new norm under the effect of global warming.