当前位置: X-MOL 学术Hydrogeol. J. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A three-dimensional stratigraphic model of the Mississippi River Delta, USA: implications for river deltaic hydrogeology
Hydrogeology Journal ( IF 2.8 ) Pub Date : 2020-06-23 , DOI: 10.1007/s10040-020-02198-8
An Li , Frank T.-C. Tsai , Brendan T. Yuill , Chenliang Wu

A three-dimensional stratigraphic model was constructed of the upper 50 m of the Mississippi River Delta, southeastern USA. The model is used to understand hydrogeological connections among the Mississippi River, adjacent interdistributary bays and groundwater systems, and to understand how stratigraphic settings affect potential anthropically induced subsidence and erosion in the region. This study uses 619 geotechnical borings throughout the area along with the multiple-indicator natural neighbor (MINN) interpolation method to construct the model. Based on available data, the study focused on the Mississippi River reach from Head of Passes (river mouth) to Jesuit Bend (108 km upstream), covering an area of approximately 1,800 km2 and ranging in elevation from 3 to −46 m. The model shows typical basal coarse-grained sand bodies overlain by 10-m-thick blanket clay, which is interbedded frequently with silty and sandy sediments and occasionally with peat and organic clay. Sands are most abundant between elevations −10 and −35 m. The Mississippi River main channel incises the underlying sands, thereby providing pathways for river–groundwater exchange. Increased hydrologic loads may propagate along the flow paths potentially giving rise to high pore-water pressure and a resultant increase in land subsidence and thus local erosion of natural and local flood-control levees. This method of analysis may apply to other deltaic regions similarly subject to anthropically accelerated subsidence and erosion.



中文翻译:

美国密西西比河三角洲的三维地层模型:对三角洲水文地质的启示

在美国东南部密西西比河三角洲的上50 m处建立了三维地层模型。该模型用于了解密西西比河,相邻的跨界海湾和地下水系统之间的水文地质联系,并了解地层背景如何影响该地区潜在的人为诱发的沉降和侵蚀。这项研究使用了整个地区的619个岩土钻孔以及多指标自然邻域(MINN)插值方法来构建模型。根据现有数据,该研究的重点是密西西比河,从通行证头(河口)到耶稣会弯(上游108公里),覆盖面积约1,800公里2且海拔范围从3到-46 m。该模型显示了典型的基底粗粒砂体,上面覆盖着厚度为10米的毯状粘土,该层经常夹有粉质和沙质沉积物,偶尔还夹有泥炭和有机粘土。在海拔-10和-35 m之间,沙子最丰富。密西西比河主河道切入下面的沙子,从而为河水与地下水的交换提供了途径。增加的水文负荷可能会沿着流径传播,从而可能导致较高的孔隙水压力,进而导致地面沉降增加,进而导致自然和局部防洪堤的局部侵蚀。这种分析方法可以适用于其他三角洲地区,它们同样受到人类加速沉降和侵蚀的影响。

更新日期:2020-06-23
down
wechat
bug