<<返回上一页

Recipe for disaster

发布时间:2019-03-08 10:10:08来源:未知点击:

By Jon Copley MOST of Honduras and large parts of Nicaragua, El Salvador and Guatemala lie devastated after their encounter with Hurricane Mitch. Yet meteorologically, Mitch was not a record breaker. What made it the most destructive Atlantic storm for decades, say experts familiar with the region, was a deadly combination of local geography and poverty. As Mitch brewed in the Caribbean, it briefly became the fourth deepest depression ever recorded in the Atlantic region, with an atmospheric pressure at its centre of just 905 millibars. The record is 888 millibars, held by Hurricane Gilbert, which hit the coast of Mexico in September 1988 and killed more than 300 people before blowing itself out. By the time Mitch hit the Honduran capital of Tegucigalpa, however, it had been officially downgraded to a tropical storm, with a pressure of 994 millibars and maximum wind speeds of around 97 kilometres per hour. “It was one of the most powerful hurricanes in the region for some time, but not when it made landfall,” says Lixion Avila of the National Hurricane Center in Miami, Florida. The problems came when Mitch hit Central America’s mountainous terrain. Its moisture-rich air cooled as it was forced upwards, unleashing a deluge that obliterated entire villages and left more than 24 000 people dead or missing, and a million homeless. Mitch also lingered over the region, prolonging the destruction. More than 600 millimetres of rain fell in the mountains of Honduras in a single day. But that alone can’t be blamed for the catastrophe. “The crucial thing is removing vegetation—if you take that out of the system, you’ve lost the natural bonding and the area will be prone to gully erosion and mass movement,” says Paul Gostelow, a soil erosion specialist at the British Geological Survey in Keyworth who has surveyed river catchments in Honduras. “A lot of land has been cleared for grazing and building, and slopes are steep, making the area typical for landsliding.” So could the disaster have been predicted? Surveys can pinpoint likely sites for landslides, says Gostelow. “Knowing the geology, topography and past and present land use can give a clue to the areas most at risk,” he suggests. “Perhaps in the future people will sit down and produce maps looking at land use. Some bits of ground are best left alone.” But this may not be an option for Central American countries, where poverty forces many people to live in substandard dwellings in dangerous areas. “People build where they want to build, with little awareness of hazards,” says David Jones,