Storm-surge flooding on the Yukon-Kuskokwim Delta, Alaska
Storm-surge flooding on the Yukon-Kuskokwim Delta, Alaska
复制标题
阿拉斯加育空-库斯科奎姆三角洲遭遇风暴潮洪水
作者：
J. Terenzi;M. Jorgenson;C. Ely
阿拉斯加的沿海地区经常受到源自海洋的强烈风暴的影响，由于全球气候变化，预计风暴的频率和强度将增加。Yukon-Kuskokwim三角洲（YKD）位于阿拉斯加西部，白令海东缘，是北美最大的三角洲系统之一。其低起伏使其特别容易受到风暴驱动的洪水潮汐和海平面上升的影响。关于风暴潮在阿拉斯加西部造成的洪水程度及其对盐碱化、海岸线侵蚀、永久冻土融化、植被、野生动物和以生存为基础的经济的影响的信息很少。在本文中，我们总结了1913 - 2011年期间阿拉斯加西部白令海地区的风暴洪水事件，并使用Radarsat-1和MODIS卫星图像绘制了YKD中部秋季风暴造成的内陆洪水范围，以及使用高分辨率IKONOS卫星图像和实地调查绘制了漂流线。最大的风暴潮发生在秋季，与涨潮和强烈（> 65公里每小时）的西南风有关。2005年、2006年和2011年，风暴潮造成的最大内陆洪水范围分别为30.3 km、27.4 km和32.3 km，洪水总面积分别占6730 km 2研究区域的47.1%、32.5%和39.4%。2005年和2011年风暴的高峰期分别高出平均海平面3.1米和3.3米，几乎与观测到的最大风暴（1974年11月）估计的3.5米高度一样高。一些历史上被遗弃的村庄遗址位于最大洪水事件的淹没区域内。随着预计的海平面上升，预计大风暴将变得更加频繁，覆盖更大的地区，对淡水池塘，非盐水栖息地，永久冻土以及筑巢鸟类和当地人使用的景观产生有害影响。
Coastal regions of Alaska are regularly affected by intense storms of ocean origin, the frequency and intensity of which are expected to increase as a result of global climate change. The Yukon-Kuskokwim Delta (YKD), situated in western Alaska on the eastern edge of the Bering Sea, is one of the largest deltaic systems in North America. Its low relief makes it especially susceptible to storm-driven flood tides and increases in sea level. Little information exists on the extent of flooding caused by storm surges in western Alaska and its effects on salinization, shoreline erosion, permafrost thaw, vegetation, wildlife, and the subsistence-based economy. In this paper, we summarize storm flooding events in the Bering Sea region of western Alaska during 1913 – 2011 and map both the extent of inland flooding caused by autumn storms on the central YKD, using Radarsat-1 and MODIS satellite imagery, and the drift lines, using high-resolution IKONOS satellite imagery and field surveys. The largest storm surges occurred in autumn and were associated with high tides and strong (> 65 km hr-1) southwest winds. Maximum inland extent of flooding from storm surges was 30.3 km in 2005, 27.4 km in 2006, and 32.3 km in 2011, with total flood area covering 47.1%, 32.5%, and 39.4% of the 6730 km2 study area, respectively. Peak stages for the 2005 and 2011 storms were 3.1 m and 3.3 m above mean sea level, respectively—almost as high as the 3.5 m amsl elevation estimated for the largest storm observed (in November 1974). Several historically abandoned village sites lie within the area of inundation of the largest flood events. With projected sea level rise, large storms are expected to become more frequent and cover larger areas, with deleterious effects on freshwater ponds, non-saline habitats, permafrost, and landscapes used by nesting birds and local people.