Collaborative Research: Sediment Sources, Transport Mechanisms, and Fluxes in a Coastal Plain Estuary

该奖项由2009年美国复苏和再投资法案(公法111-2)资助。该研究将通过对特拉华河河口的调查，促进对河口泥沙扩散的了解。计划对水柱泥沙通量、沉积和再悬浮进行协调研究，PIS希望确定河口的泥沙捕获效率是外部作用力的函数，包括河流流量、潮汐和风。将部署一系列仪表式系泊设备，以获得流量和悬浮泥沙浓度的连续时间序列记录，以及一套按季节测量的自然和人为放射性核素。具体目标是：1)根据7Be、210Pb和137Cs的分布确定细颗粒泥沙的来源、输送路径和停留时间；2)通过对泥沙通量的现场观测，评估航道形态对沿河口和跨河口泥沙输送和沉积模式的作用；以及3)阐明泥沙通量和捕获负责维持河口最大浑浊度的机制，以及将泥沙从轴向水道转移到潮下滩的机制。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-2).The study will promote understanding of sediment dispersal in estuaries through an investigation of the Delaware River estuary. Coordinated studies of water-column sediment flux, deposition, and resuspension are planned and the PIs hope to establish the sediment trapping efficiency of the estuary as a function of external forcings, including river discharge, tides and wind. An array of instrumented moorings will be deployed to obtain continuous time-series records of flow and suspended-sediment concentration, and a suite of naturally occurring and anthropogenic radionuclides measured seasonally. Specific objectives are: 1) to identify the sources, transport pathways, and residence times of fine sediment based on distributions of 7Be, 210Pb, and 137Cs; 2) to asses the role of channel morphology on along- and across-estuary patterns of sediment transport and deposition using in-situ observations of sediment flux; and 3) to elucidate the mechanisms of sediment flux and trapping responsible for maintaining the estuary turbidity maximum, and which transfer sediment from the axial channel to subtidal flats.