Seismic Risk and Mountain Environments: The Role of Surface Conditions in Earthquake Disaster

Abstract

The paper examines the extent to which damages in earthquake disasters depend upon features of mountain land environ- ments and human settlement of them. The damage zones of nine out of ten major disasters in recent decades involve mountainous areas. Destructive failure of steep slopes is one recurrent, globally significant indicator of the role of mountainous terrain. Weather and problems of access relating to mountain extremes and terrain are also frequent and serious problems for survival and relief in disaster. It was also found that many of the detailed problems stem from, or have been magnified by, recent ecological and societal changes in the mountains. However, it is the mountain foot and mountain fringe areas where the greatest extent and concentrations of damage occur. Patterns of damage in most earthquake disasters accord with patterns of mountain foot settlement, the complex environment of piedmont ecotones and land uses. Herein lies much of the explanation for geographical concentrations of the disasters in drier lands and coastal settings. Pressures of recent insensitive ecological and social change in these areas, where there are sharp and sudden contrasts in susceptibility to seismic shaking, seem to be a major factor in many of the damages recorded.