Theworld can expect to see more catastrophic landslides, disasters such as the oneswhich exacted a death toll of over 200 in two central Javan villages recently.Experts warn that climate change-related increases in the number and intensityof typhoons and hurricanes would produce in tandem a rising danger of landslides.Increasing rainfall intensities and frequencies, coupled with populationgrowth can drastically increase landslide-associated casualties, especially indeveloping countries where pressure on land resources often lead to slopecultivation and slope agriculture which are very much prone to landslidedisasters, according to scientists gathered in Tokyo, Japan, for a three-daymeeting on landslide prevention.
A statement issued by the conference organisers United Nations University (UNU), Kyoto University and Unesco says thatclimate change might promote landslides in other ways as well. A Decemberlandslide that claimed 60 lives in Yemen was blamed on mountain bouldersshifting due to changes in temperature. Other landslide inducements includeearthquakes, volcanic eruption, poorly planned developments and mining.
Asia suffered by far the most landslides of anyregion 220 in the past century. But landslides in North, Central and SouthAmerica caused the most deaths and injuries (over 25,000), while Europes arethe most expensive, incurring damage of almost US$23mil (RM87.4mil) each time.Among natural disasters, landslides rank as the seventh biggest killer, afterdroughts, windstorms, floods, earthquakes, volcano and extreme temperature. Eachlandslide occurring in the past 20 years claimed 800 to1,000 lives on average.Landslides also threaten some of the worlds most precious cultural sites,including Egypts famous Valley of the Kings, home to the Pharaohs Tombs; theHuaqing Palace, built in the Tang dynasty (618 to 907) in Lishan, China; andsite of Machu Picchu, Peru, the mountaintop fortress city of the ancient Incas.
Advanced countries are not spared from landslides.A study found that in Japan, landslides occurred annually for 35 years, between1967 and 2002, killing 3,300 people. Japan has reported annual losses of US$4bilto US$6bil (RM15.2bil to RM22.8bil) from landslides, while India, Italy and theUnited States each reported between US$1bil and US$2bil (RM3.8bil to RM7.6bil).
Experts worry that many countries lack thefollowing: resources to investigate risks and identify hazard zones; politicalcommitment to reduce risks such as through land use planning; safe buildingcodes and regulations; and expertise in landslide risk reduction. Strategies to reduce landslide losses will be considered at the meeting of 100experts from 14 nations but United Nations undersecretary-general Hans vanGinkel says there is no one-size-fits-all strategy. The question is,short of recommending unrealistic bans on development in areas that couldsomeday be affected, what would best protect people against the high costs oflandslide disasters?. In developing agricultural countries where thepopulation is distributed over a wide area characterised by steep slopes andintense rainfall, avoiding landslides requires slope preservation throughappropriate drainage and retaining structures.
UNU scientist Srikantha Herath says early warningplays a critical role in reducing death and suffering from landslide disasters.Recent advances in short-term rain forecasts, together with mathematicalmodels that predict the surface and subsurface water movement, should beharnessed to detect and warn of potential landslide locations. Much work isneeded in this area including development of appropriate monitoring andmodelling tools. These efforts should go hand in hand with mapping of landslidehazard hot spots coupled with community education.
Officials at the meeting will considerdesignating 2007 as World Landslide Year and priority action such as monitoringand early warning systems, hazard mapping, landslide threats induced byearthquakes and heavy rains, education and online database.