Japanese offer lessons in prevention of mudslides

While the government comes under criticism in the aftermath of Typhoon Toraji for its failure to prevent mudslides, disaster-prevention experts say that Taiwan could learn much from Japan. Both countries are densely populated and habitable land is in short supply.

"Taiwan is much less cautious than Japan about the threat of mudslides," said Shieh Chjeng-lun (謝正倫), an engineering professor at National Cheng Kung University.

Shieh said Taiwan did not begin to conduct surveys of dangerous rivers until the early 1990s and specific areas threatened by potential mudslides were not officially identified and designated as such until 1996.

Government action that has been taken on mudslide-disaster prevention was triggered in the early 1990s by the increasing frequency of mudslides.

In 1959, the country was hit by mudslides as a result of flooding in several counties in central Taiwan in August.

After that, mudslides attracted little attention from the government until June 1990, when Typhoon Ofelia hit Hualien County. The catastrophe almost destroyed one village, killing 19 people. Six victims are still officially listed as "missing." Twenty-four homes were destroyed and 68 people made homeless.

Although the government began to work with National Cheng Kung University's Disaster Prevention Research Center in the early 1990s to establish a warning system to monitor mudslide-prone areas in the country, the results of the collaboration were disappointing.

In August 1991, Typhoon Nat, so strong that it swept several cars into the Pacific Ocean, triggered mudslides in Taitung County.

In July 1994, Typhoon Tim caused extensive losses resulting from mudslides in Hualien.

The government learnt its most tragic lesson, however, in the summer of 1996, after Typhoon Herb claimed 15 lives, caused 10 major bridges to collapse and caused heavy agricultural losses. Typhoon Zeb in 1997 also triggered mudslides in mountain areas.

The mudslide warning system, comprising 18 monitoring stations, each costing more than NT$1 million, was criticized for its inaccuracy, despite claims to have had a 30 percent higher accuracy rate than its Japanese counterpart.

It often issued warnings but no mudslides materialized. When mudslides occurred, no warnings were issued. Residents living in mudslide-prone areas did not know if they had to evacuate because they had no confidence in the system.

The warning system was terminated in 1998. The government turned the remaining 15 operational stations into rainfall monitoring stations.

Shieh, head of the Disaster Prevention Research Center, said it was a pity that the warning system had been terminated because the 30 percent accuracy that it did achieve was better than the 20 percent achieved by Japan.

But Shieh said that Japan's warning system was more comprehensive and integrated than Taiwan's, whose 18 stations had monitored more than 780 potential mudslide sites.

"The fundamental difference between Taiwan and Japan is peoples' attitude toward natural disasters," Shieh said.

Shieh said that Japan revised its Water Conservancy Act to ensure the ability of buildings to resist flooding and mudslides after the 1995 Kobe Earthquake.

He said that Taiwan's government was more reluctant to address natural disasters than Japan.

Seventy-one percent of Japan is covered by forest. Bad weather conditions, such as typhoons, rainstorms, tornadoes and monsoon rains, can result in a wide range of natural disasters, including flooding, landslides, storm surges and tidal waves.