Channel Properties Where Fluvial and Tidal Currents Meet

该项目将调查潮汐在河口上游数十至数百公里处的能量是如何被消耗的，并导致河流逆流。这项工作是新颖的，在科学上是重要的，因为它提供了一个水动力学框架来连接河流连续体的两个部分，河流和河口通道，这在以前是分开处理的。我们将测量河道尺寸、泥沙特性、流速剖面和河流湍流应力，并模拟潮汐向上游推进时能量的变化。在河水从单纯的下游流向转变为受潮汐影响的河段，我们假设潮汐能量耗散过程导致河床侵蚀加剧，从而形成一种特征的河流形态。这项研究的结果将有助于阐明：1)如何管理大坝放水以减少下游的侵蚀，2)河床栖息地的发展和稳定，以及3)向沿海地区的沉积物排放。此外，这项工作将有助于描述海平面上升对内陆河流的影响。

This project will investigate how energy in tides is consumed as they advance tens to hundreds of kilometers upstream of the river mouth, and cause river currents to reverse. This work is novel and scientifically important because it provides a hydrodynamic framework for linking two parts of the river continuum, fluvial and estuarine channels, which heretofore had been treated separately. We will measure channel dimensions, sediment properties, velocity profiles, and turbulent stresses in river flows, and model the changes in energy as tides advance upstream. In the section of the river where flows transition from solely downstream flow to becoming influenced by tides, we hypothesize that tidal energy dissipation processes lead to enhanced riverbed erosion, giving rise to a characteristic river form. Findings from this study will help shed light on: 1) how to manage dam water releases to minimize erosion downstream, 2) the development and stability of river bed habitats, and 3) sediment discharge to the coastal zone. Moreover, this work will help characterize the effects of sea level rise on rivers far inland.