Global Environmental Change Part B: Environmental Hazards最新文献

This study quantifies the spatial relationship between the global distribution of human population and recent volcanism. Using recently compiled databases of population and Holocene volcanoes, we estimate that almost 9% (455×10⁶ people) of the world's 1990 population lived within 100 km of an historically active volcano and 12% within 100 km of a volcano believed to have been active during the last 10,000 years. The analysis also indicates that average population density generally decreases with distance from these volcanoes (within 200 km). In tropical areas, the elevation and fertile soils associated with volcanic regions can provide incentives for agrarian populations to settle close to potentially active volcanoes. In Southeast Asia and Central America higher population densities lie in closer proximity to volcanoes than in other volcanic regions. In Japan and Chile, population density tends to increase with distance from volcanoes. The current trends of rapid urbanization and sustained population growth in tropical developing countries, combined with agricultural intensification of fertile volcanic terrains could alter the relationship between humans and volcanoes so as to increase both local and global consequences of volcanic eruptions in the future.

With over six million buildings located within the boundaries of the 100-yr floodplain, flood losses across the United States are widespread (88% of US counties experienced at least one flood disaster during the second half of the twentieth century). To deal with this problem, the federal government provides flood insurance through the National Flood Insurance Program, which was initiated by Congress in 1968 and amended significantly in 1969, 1973, and 1994. This article describes the US approach to flood insurance and notes a number of problems that have limited its effectiveness. Flood hazard identification is incomplete, and methods used are flawed. Mitigation has failed to contain increasing exposure to property damage in floods and coastal storms, and it has failed to markedly reduce exposure to loss of older buildings located in flood hazard areas. Market penetration of flood insurance is low, in spite of mandatory purchase requirements for new construction and the availability of subsidized insurance rates for older buildings located in flood-hazard areas. These problems, although serious, can be remedied through a variety of actions taken by governments at the federal, state, and local level.

This paper sets out an examination of natural disaster amongst small island developing states (SIDS), and presents a framework for assessing the interaction of global pressures and local dynamics in the production of human vulnerability. Change at the global level is found to be a source of new opportunities as well as constraints on building local resilience to natural disaster. Much depends on the orientation of the state in global economic and political systems. The United Nations is a key global actor with relevance to shaping vulnerability in island states, and the impact of the UN Decade for Natural Disaster Reduction is reviewed. It is concluded that this is a critical time for SIDS which must contend with ongoing developmental pressures in addition to growing pressures from risks associated with global environmental change and economic liberalisation that threaten their physical and economic security.

The Ganges, Brahmaputra and Meghna/Barak rivers are lifelines for millions of people in South Asia in Nepal, India, Bhutan and Bangladesh. They supply water for food and fibre production and for industrial and domestic purposes. They are also sources of disastrous floods that cause substantial damage to agriculture and infrastructure in these countries. There are claims that flood discharges, areal extent, and damage-costs are getting worse in the Ganges, Brahmaputra and Meghna/Barak basins. The validity of these claims was examined by applying four different statistical tests to the peak discharge time series and flooded areas. The results indicate that no conclusive changes have occurred over the last few decades. Reports of increased flood damage may be due to a combination of other factors, such as improved damage assessment techniques, and the expansion and intensification of settlement in flood-prone areas, but this was not tested in this paper and should be top priority for future research.

The vulnerability of megacities to hazards was highlighted during the recent International Decade for Natural Disaster Reduction, yet in many respects residents of small cities and rural communities are more vulnerable to disasters. Small cities and towns, deprived of the political and economic influence of megacities, lack the potential to suffer catastrophic losses that would seriously impact the global economy. Megacities, however, have greater disaster resilience.

Hazard vulnerability of communities, ranging from small towns to megacities, can best be viewed as the summation of a continuum of conditions that define physical and social exposure, disaster resilience, pre-event mitigation or preparedness, and post-event response. Megacities have large populations at risk, but have the greatest resources to deal with hazards and disasters. Small communities have far smaller populations at risk, but often far higher proportions of their populations can be vulnerable. The impacts of many disasters can be experienced over the entirety of smaller communities, but many hazards lack the spatial dimension to affect an entire metropolitan area.