Fresh Water Studies Commons^™

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 …

Macroinvertebrates And Excessive Fine Sediment Conditions In Oregon Coastal Streams, Patrick M. Edwards

Dissertations and Theses

The Pacific Coastal ecoregion contains large tracts of economically important forest lands that also serve as critical stream habitat for endangered Salmonids. Excessive fine sediment deposition in streams of this region is a major environmental concern in the region but difficult to measure directly. The use of stream invertebrates to monitor fine sediment conditions in streams requires careful consideration of several important factors that complicate their use as bioindicators including high spatial and temporal variability and covariance with other environmental variables.

To evaluate the use of stream invertebrates as bioindicators of excessive fine sediment, three hypotheses were tested. The first …

Spokane River In Idaho And Washington Tmdl Water Quality And Hydrodynamic Modeling Quality Assurance Project Plan -- Draft, Scott A. Wells, Chris Berger

Civil and Environmental Engineering Faculty Publications and Presentations

The focus of this present study is to perform the following tasks:

• Converting the Upper Spokane River CE‐QUAL‐W2 models (Washington and Idaho) to version 3.6

• Combining the Washington and Idaho models

• Reviewing and updating model boundary conditions

• Check model calibration

• Meet with stakeholders

• Develop and Run Modeling Scenarios

• Create reports on calibration and scenario runs

Waldo Lake Research In 2003, Mark D. Sytsma, John Rueter, Richard Petersen, Roy Koch, Scott A. Wells, Rich Miller, Laura Johnson, Robert Leslie Annear

Civil and Environmental Engineering Faculty Publications and Presentations

This report summarizes the first year of an effort to develop a more complete understanding of the physical, chemical, and biological characteristics that drive the ecological processes of Waldo Lake. Modern limnology recognizes the importance of watershed processes as well as in- lake processes in lake ecosystem functioning. Therefore, the approach included consideration of watershed hydrology and forcing functions that determine hydrodynamics of the system as well physical and chemical factors that may be important in regulating primary production in the lake. Data collected since 1998 was summarized and bathymetry of the basin was mapped using state-of-the-art digital depth sounding …

Theoretical Basis For The Ce-Qual-W2 River Basin Model, Scott A. Wells, Thomas M. Cole

Civil and Environmental Engineering Faculty Publications and Presentations

The primary objective of this research is to integrate a riverine model into the existing W2 code that would provide the capability for modeling entire watersheds. This task was accomplished by the following steps:

• Formal derivation of governing equations and solution algorithm with general channel slope

• Detailed analysis of algorithm for linking branches and smooth implementation of boundary conditions between branches

• Algorithm development and changes to basic model code (including branch definitions with slope, slope correction to solution algorithm, transfer of momentum between internal branches)

These tasks were performed with the following constraints and initiatives:

• Utilize …

Variation Of Constitutive Model Formulation On Analytical Cake Filtration Models, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Constitutive properties are required to model porosity, effective stress, porewater pressure, or permeability during cake filtration. By using an analytical cake filtration model based on Tiller (1975) with various constitutive property formulations, predictions of effective stress, permeability, and porosity distributions in a filter cake can be made. This analytical approach was only valid when spatially average values of porosity and pressure differential were constant over time. Several different constitutive property formulations were compared to data of effective stress and permeability as a function of porosity for kaolin clay in water. Also the spatial distribution of porosity in a filter cake …

Modeling The Bull Run River-Reservoir System, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The City of Portland, Water Bureau currently operates 2 Bull Run reservoirs, Reservoir #2 and Reservoir #1 as a water supply source in the Bull Run watershed shown in Figure 1 and Figure 2. The Water Bureau wants to operate their water supply system in order to meet both water supply objectives and fish habitat objectives downstream of the Bull Run reservoirs in Bull Run River. In addition, a third Bull Run reservoir has been proposed as an additional water supply source. This reservoir also may be used to meet water supply and fish habitat objectives in Bull Run River. …

Review Of The United States Environmental Protection Agency Superfund Technical Assistance Grant Program, Robert Leslie Annear, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael Cummings, Richard Pratt

Civil and Environmental Engineering Faculty Publications and Presentations

The EPA Technical Assistance Grant Program has been around for several years, but there are not many examples of its use in the Pacific Northwest from which citizens can learn from when considering applying for a Technical Assistance Grant. The EPA program is designed to provide citizens with technical assistance in understanding the issues related to a Superfund site (or proposed Superfund site) in their community. This report provides an overview of the Technical Assistance Grant Program with information on applying for the grant, selecting a Technical Advisor and managing the grant. Additionally two case studies are reviewed in order …

The Columbia Slough, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

This report was written in an attempt to provide the public and Bureau of Environmental Services Staff with a summary of work accomplished on the Columbia Slough system by Portland State University and other consultants working on the Slough over the last 6 years. An attempt was made to create an easy-to-read report with important overviews of the "big picture", glossary of definitions, index, and further details to assist in technology transfer.