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.
