Effective sea-level rise and deltas:: Causes of change and human dimension implications
Effective sea-level rise and deltas:: Causes of change and human dimension implications
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DOI：
10.1016/j.gloplacha.2005.07.004
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发表时间：
2006-02-01
影响因子：
3.9
通讯作者：
Meybeck, M
中科院分区：
文献类型：
--
作者：
Ericson, JP;Vörösmarty, CJ;Meybeck, M
对分布在世界各地的40个三角洲样本的当代有效海平面上升（ESLR）进行了评估。对于任何三角洲，ESLR是一个净速率，由海平面上升、河流沉积物沉积和沉降的自然总速率以及地下水和碳氢化合物开采引起的加速沉降的组合定义。ESLR估计在目前的条件下，使用三角洲边界的数字数据集和三角洲动态的一个简单的模型。本研究中的三角洲代表了所有主要的气候带、人口密度水平和经济发展程度。总的来说，采样的三角洲作为河流流域的终点，排放着地球30%的陆地和42%的全球陆地径流。近3亿人居住在这些三角洲。对于当代基线，ESLR估计值范围为0.5至12.5毫米/年（-1）。河流沉积物的淤积减少，造成上游淤积的人工蓄水池和消耗损失的径流灌溉是主要的决定因素ESLR在近70%的三角洲。大约20%的三角洲显示出加速下沉，而只有12%的三角洲显示出海平面上升的主要影响。外推到2050年的ESLR当代率显示，870万人和28,000平方公里的三角洲地区的三角洲样本集可能会遭受更严重的洪水和增加海岸侵蚀。当考虑到风暴潮增加的洪水风险时，人口和淹没面积显着增加。这项研究发现，直接的人为影响决定了ESLR在大多数三角洲研究，与海平面上升相对不那么重要的作用。因此，对人类在全世界三角洲地区居住的严重挑战是由迄今为止研究得不如气候变化-海平面上升问题全面的因素所传达的。(c)2005 Elsevier B. V.保留所有权利。
An assessment is made of contemporary effective sea-level rise (ESLR) for a sample of 40 deltas distributed worldwide. For any delta, ESLR is a net rate, defined by the combination of eustatic sea-level rise, the natural gross rate of fluvial sediment deposition and subsidence, and accelerated subsidence due to groundwater and hydrocarbon extraction. ESLR is estimated under present conditions using a digital data set of delta boundaries and a simple model of delta dynamics. The deltas in this study represent all major climate zones, levels of population density, and degrees of economic development. Collectively, the sampled deltas serve as the endpoint for river basins draining 30% of the Earth's landmass, and 42% of global terrestrial runoff. Nearly 300 million people inhabit these deltas. For the contemporary baseline, ESLR estimates range from 0.5 to 12.5 mm yr(-1). Decreased accretion of fluvial sediment resulting from upstream siltation of artificial impoundments and consumptive losses of runoff from irrigation are the primary determinants of ESLR in nearly 70% of the deltas. Approximately 20% of the deltas show accelerated subsidence, while only 12% show eustatic sea-level rise as the predominant effect. Extrapolating contemporary rates of ESLR through 2050 reveals that 8.7 million people and 28,000 kin 2 of deltaic area in the sample set of deltas could suffer from enhanced inundation and increased coastal erosion. The population and area inundated rise significantly when considering increased flood risk due to storm surge. This study finds that direct anthropogenic effects determine ESLR in the majority of deltas studied, with a relatively less important role for eustatic sea-level rise. Serious challenges to human occupancy of deltaic regions worldwide are thus conveyed by factors which to date have been studied less comprehensively than the climate change-sea-level rise question. (c) 2005 Elsevier B.V. All rights reserved.