The ups and downs of levees: GPS–based change detection, Middle Mississippi River, USA
The ups and downs of levees: GPS–based change detection, Middle Mississippi River, USA
复制标题
堤坝的起伏：基于 GPS 的变化检测，密西西比河中部，美国
DOI：
--
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
J. Remo
中科院分区：
文献类型：
--
作者：
A. Flor;N. Pinter;J. Remo
1998年和2007年，在密西西比河圣路易斯和伊利诺伊州开罗之间328公里的密西西比河堤防沿线测量了堤顶海拔的变化。我们还将1998年和2007年的调查数据与50年来的洪水高程数据进行了比较，以评估堤防保护水平。堤防高度、稳定性和安全是全国性的问题，特别是自2005年卡特里娜飓风和路易斯安那州新奥尔良的洪水墙倒塌以来。大多数被调查的堤坝在9年的测量间隔内稳定在厘米到分米的水平。其他地区也出现了变化，包括1998至2007年间增加了多达1.49米，减少了多达1.26米。增加的原因是当地的裂缝修复、小规模的道路维护和更大的堤坝抬高工程。堤防高程的降低被解释为小范围的地表侵蚀和堤防和/或地基材料的较大压实或下沉。2007年的堤顶在当地比50年的标准海拔低2.0米。堤防退化降低了对平原居民的保护水平，通常没有明显的症状。在没有必要的研究、工程或许可的情况下故意抬高堤防会产生一系列潜在的负面影响，包括错误的安全感和将洪水风险输出到邻近堤防社区的可能性。堤防高程和随时间变化的区域测量可以为评估堤防条件、稳定性和遵守堤防法规提供初步工具。
Changes in levee-crest elevations were measured along 328 km of Mississippi River levees between St. Louis, Missouri, and Cairo, Illinois, in 1998 and 2007. We also compared 1998 and 2007 survey data with 50 yr fl ood elevation profi les to assess levels of levee protection. Levee heights, stability, and safety are nationwide concerns, especially since Hurricane Katrina and fl oodwall failures in New Orleans, Louisiana, in 2005. The majority of surveyed levees were stable at the centimeter to decimeter level during the 9 yr measurement interval. Change was measured in other areas, including increases of as much as 1.49 m and decreases of as much as 1.26 m between 1998 and 2007. The increases corresponded to local crevasse repairs, smallscale road maintenance, and larger levee-raising projects. Decreases in levee elevations are interpreted as small-scale surface erosion and larger compaction or subsidence of levee and/or foundation materials. Levee crests in 2007 were locally as much as 2.0 m below the 50 yr fl oodgrade elevations. Levee degradation reduces protection levels for fl oodplain residents, often without easily visible symptoms. Intentional levee raising without necessary studies, engineering, or permitting has a range of potential negative impacts including both a false sense of security and the potential for exporting fl ood risk to neighboring levee communities. Regional surveying of levee elevations and change over time can provide a preliminary tool for assessing levee conditions, stability, and compliance with levee regulations.