natural levee

基本解釋

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為決口。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(qū)識別出水下分流河道、水下分流河道堤泛沉積、河口砂壩、遠(yuǎn)河口砂壩、分流間灣、前緣席狀砂等微相。
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、溢岸砂多為含泥粉砂、粉砂質(zhì)泥和純泥，很難成為有效儲層。

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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