Changing global patterns of urban exposure to flood and drought hazards
Changing global patterns of urban exposure to flood and drought hazards
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DOI：
10.1016/j.gloenvcha.2015.01.002
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发表时间：
2015-03-01
影响因子：
8.9
通讯作者：
Liu, Ying
中科院分区：
文献类型：
--
作者：
Gueneralp, Burak;Gueneralp, Inci;Liu, Ying
对城市日益遭受各种自然灾害所造成的人力和经济损失进行量化的研究，考虑到气候变化以及人口和经济活动水平的增加，但假设城市范围不变。然而，要准确估计由于城市风险敞口的变化而造成的潜在损失，我们需要知道它们未来将在哪里增长。在这里，我们首次对2000年至2030年城市土地扩张导致的城市基础设施遭受洪水和干旱的风险进行了估计。到2030年，位于低海拔海岸带（LECZ）内的全球城市土地比例仅略微增加至13%;尽管如此，这相当于LECZ内城市土地数量增加230%（从71，000 km（2）增加到234，000 km（2））。2000年，全球约30%的城市土地（即，近200，000 km（2））位于高频率洪水区;到2030年，这将达到40%（即，超过700，000公里（2））。非洲和亚洲新兴的沿海大都市地区将比发达国家的大都市地区更大，面临洪水的地区也更大。旱地的城市范围将增加近30万公里（2），达到近50万公里（2）。总体而言，如果不考虑气候变化的潜在影响，到2030年，城市地区遭受洪水和干旱危害的程度将分别增加2.7倍和近2倍。在全球范围内，遭受洪水和干旱的城市土地预计将增加250%以上。受洪水或干旱或两者同时影响的城市扩张速度和规模在地理上有很大差异。有几种政策选择可以保护城市基础设施免受水灾和旱灾的危害。这些措施包括将发展方向从洪水或干旱易发区转移到大规模采用“绿色基础设施”（或“生态高效基础设施”）。今天就管理易受这些灾害影响的地区的城市增长所作的决定，可以在减轻不久的将来可能因洪水和干旱造成的损失方面发挥重大作用。(C)2015爱思唯尔有限公司版权所有。
The studies that quantify the human and economic costs of increasing exposure of cities to various natural hazards consider climate change together with increasing levels of population and economic activity, but assume constant urban extent. Accurate estimates of the potential losses due to changing exposure of cities, however, require that we know where they will grow in the future. Here, we present the first-ever estimates of the changing exposure of urban infrastructure to floods and droughts due to urban land expansion from 2000 to 2030. The percentage of the global urban land that lies within the low elevation coastal zone (LECZ) increases only slightly to 13% by 2030; nonetheless, this corresponds to a 230% increase in the amount of urban land within the LECZ (from 71,000 km(2) to 234,000 km(2)). In 2000, about 30% of the global urban land (i.e., nearly 200,000 km(2)) was located in the high-frequency flood zones; by 2030, this will reach 40% (i.e., over 700,000 km(2)). The emerging coastal metropolitan regions in Africa and Asia will be larger than those in the developed countries and will have larger areas exposed to flooding. The urban extent in drylands will increase by nearly 300,000 km(2), reaching almost 500,000 km(2). Overall, without factoring in the potential impacts from climate change, the extent of urban areas exposed to flood and drought hazards will increase, respectively, 2.7 and almost 2 times by 2030. Globally, urban land exposed to both floods and droughts is expected to increase over 250%. There are significant geographical variations in the rates and magnitudes of urban expansion exposed to floods or droughts or both. Several policy options exist to safeguard urban infrastructure from flood and drought hazards. These range from directing development away from flood- or drought-prone zones to large-scale adoption of "green infrastructure" (or "eco-efficient infrastructure"). Decisions, taken today on managing urban growth in locations exposed to these hazards, can make a big difference in mitigating likely losses due to floods and droughts in the near future. (C) 2015 Elsevier Ltd. All rights reserved.