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Portland State University

Series

Columbia River Estuary (Or. and Wash.) -- Ecology

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Tidal-Fluvial And Estuarine Processes In The Lower Columbia River: Ii. Water Level Models, Floodplain Wetland Inundation, And System Zones, David A. Jay, Amy B. Borde, Heida Diefenderfer Sep 2016

Tidal-Fluvial And Estuarine Processes In The Lower Columbia River: Ii. Water Level Models, Floodplain Wetland Inundation, And System Zones, David A. Jay, Amy B. Borde, Heida Diefenderfer

Civil and Environmental Engineering Faculty Publications and Presentations

Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland …


Seasonal Variability And Estuary-Shelf Interactions In Circulation Dynamics Of A River-Dominated Estuary, Arun Chawla, David A. Jay, Antonio M. Baptista, Michael Wilkin, Charles Seaton Jan 2008

Seasonal Variability And Estuary-Shelf Interactions In Circulation Dynamics Of A River-Dominated Estuary, Arun Chawla, David A. Jay, Antonio M. Baptista, Michael Wilkin, Charles Seaton

Civil and Environmental Engineering Faculty Publications and Presentations

The long-term response of circulation processes to external forcing has been quantified for the Columbia River estuary using in situ data from an existing coastal observatory. Circulation patterns were determined from four Acoustic Doppler Profilers (ADP) and several conductivity-temperature sensors placed in the two main channels. Because of the very strong river discharge, baroclinic processes play a crucial role in the circulation dynamics, and the interaction of the tidal and subtidal baroclinic pressure gradients plays a major role in structuring the velocity field. The input of river flow and the resulting low-frequency flow dynamics in the two channels are quite …