natural levee

基本解释

A gap eroded by flood waters cutting through a natural levee. Cracks in the top of a glacier.
洪水切割天然堤所侵蝕出的缺口稱爲決口。冰川頂部的裂隙可稱冰隙。
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There are 7 sedimentary microfacies that can be recognized, including underwater distributive river course, estuarine bar, submerged natural levee, etc.
研究區識別出水下分流河道、水下分流河道堤泛沉積、河口砂垻、遠河口砂垻、分流間灣、前緣蓆狀砂等微相。
The natural levee, crevasse splay and overbank sand are difficult to be effective reservoir for their content of mud-bearing silt, silty mud and unmixed mud.
天然堤、決口扇、溢岸砂多爲含泥粉砂、粉砂質泥和純泥，很難成爲有傚儲層。

Dr. VIRGINIA BURKETT (Chief, Forest Ecology Branch, National Wetlands Research Center, U.S. Geological Survey): For example, where we have artificial fill, the subsidence rates are much more rapid than they are on the natural levee deposits.
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