Engineers at MIT have devised a simple yet effective system for determining an area's landslide risk, a tool that could help planners improve building codes, determine zoning and strengthen mitigation measures in mountainous tropical regions frequently hit by typhoons.
Devised originally for Baguio City, Philippines--a city that averages five typhoons annually and holds the world record for most precipitation received in a 24-hour period (46 inches on July 14-15, 1911)--the risk rating system relies on data commonly available in developing countries. The engineers use information about the history of landslides, the type of bedrock underlying a slope, the inclination of the slope and the type of vegetation growth to determine an area's hazard rating, which they then look at in combination with land use and population density to determine the overall risk rating.
"The system could be applied directly to any country with similar topography, geology and climate, which would be much of Southeast Asia," said Herbert Einstein, a professor in the MIT Department of Civil and Environmental Engineering. He and Artessa Saldivar-Sali, a Filipino who spent summers with her family in Baguio, developed the system as part of her master's degree thesis work.
The two report in the May 2007 issue of Engineering Geology that the new landslide risk rating system is especially applicable to many areas of the developing world, where a detailed landslide risk analysis has not previously been performed, because the system is based on characteristics that can be assessed in the field or from available records.
"The fact that the Baguio area has constant, heavy rainfall makes it very susceptible to landslides, which occur frequently. Although everybody knows that, nobody has ever put a system in place to determine where this risk or hazard is higher," said Saldivar-Sali. In her thesis, Saldivar-Sali reports some 65 recorded landslides near Baguio Cit
Contact: Patti Richards
Massachusetts Institute of Technology