For landslide scientists Taiwan has an almost mythical status, being one of the few places on Earth in which almost every conceivable type of landslide occurs on a frequent basis. The rare combination of high rates of uplift, weak rocks, steep slopes, frequent earthquakes and extreme rainfall events means that the landscape has an extraordinary natural susceptibility to landslides and debris flows. There is nowhere better to study these phenomena, and unsurprisingly landslide researchers have traveled from around the world to the central mountains of Taiwan.
Personally, I feel privileged to have been able to work on landslides in Taiwan since 1991, and it is a country that I continue to visit on an annual basis at least. Of course the reasons why Taiwan is of such interest to landslide scientists are also the reasons why it can be such a challenging landscape in which to live. When the World Bank reported in 2005 on its “Disaster Hotspots” study it noted that: “Taiwan may be the place on Earth most vulnerable to natural hazards, with 73 percent of its land and population exposed to three or more hazards.”
The last great disaster, the Chi-Chi [921] Earthquake, which happened almost exactly a decade ago, was a wake-up call to the hazards that mountain communities in particular face in Taiwan. It is undoubtedly true that a huge amount has been achieved in Taiwan to reduce disaster risk since this event, but the Typhoon Morakot disaster shows that there is so much more to do.
Inevitably, and understandably, there is now a great deal of concern in Taiwan about the viability of its mountain communities in particular. As with many other mountains areas around the Pacific Rim the issues facing these communities are complex — many mountain villages are inhabited by some of the least affluent people in society, but these are people with long established links to the landscape who are often passionate in their desire to remain in their rural communities. Simple measures to relocate these people away from the mountains are rarely viable or successful from the perspective of the people involved.
An alternative approach has been widely adopted in Japan, which has been to undertake engineering works on a massive scale to render the landscape less dangerous. However, such works are extremely expensive and are hugely damaging to the environment. In the mountains of Taiwan it is likely that such measures will have limited success, and the landscape will have been irreparably damaged.
Unfortunately, in Taiwan much of the recent development in mountain areas, even in national parks and scenic areas, has been undertaken without fully considering the ways in which humans and natural processes interact in this type of environment. In many cases this is quite understandable — the processes that operate in the landscapes of Taiwan are so dynamic that our understanding of them is remarkably poor, especially during large typhoons — but the consequences are tragic.
The race to build mountain hotels is perhaps the most obvious case, as Morakot so clearly showed, but there are many other examples. As roads, hydroelectric schemes, fruit farms, recreation areas and many other developments cause extensive environmental degradation, the landscape is responding with increased rates of erosion, mainly in the form of landslides, debris flows and floods, that put the population, buildings and infrastructure at unacceptable levels of risk.
RSS