Physical Sciences and Mathematics Commons^™

Flood Dynamics In The Portland Metropolitan Area, Past, Present, And Future, Lumas Terence Helaire

Dissertations and Theses

The Portland area has an extensive flood history since it was founded in 1845. In the late 19th century, the Portland area was prone to flooding from snowmelt freshets (3-6 months duration) and brief winter rain or rain-on-snow events. Since that time the magnitude of spring freshets has been curtailed by 45% due to climate change, flow diversions, and reservoir management. Along with changes in hydrology, the bathymetry of the Lower Columbia River has been altered by the dredging of the navigation channel, diking, and land reclamation. To understand how these changes in hydrology and bathymetry have affected tidal and …

Impact Of Titanium Dioxide Nanoparticles On Nutrient And Contaminant Reduction In Wastewater Treatment Wetlands, Madeline Hubbard

Civil and Environmental Engineering Master's Project Reports

Metallic nanoparticles are found in a variety of commercial products and industrial processes, and have become more common in the last few decades. As nanoparticles are toxic to biota and have the potential to spread other types of contamination, their increased use has become a concern. Research into the transport of nanoparticles in subsurface and surface waters shows a wide range in mobility, but that they are most likely to collect in systems with low linear velocities and high organic content. As a result, wetlands are the most vulnerable to nanoparticle contamination. Wetlands receiving and treating wastewater effluent have an …

Stormwater Treatment Effectiveness Of Established Bioretention Facilities In Portland, Oregon, Emma Rose Kohlsmith

Dissertations and Theses

Bioretention systems are commonly used to treat and detain stormwater runoff and help mitigate for many negative effects of urbanization. Despite the widespread use of bioretention systems, few field-based studies have assessed how these facilities affect water quality many years after installation. The goal of this project is to assess the pollution reduction effectiveness of lined bioretention facilities that have been in use and functioning for 4-8 years. To meet this objective, this project measured water quality characteristics of stormwater flowing into and out of seven facilities installed throughout Portland, Oregon during real storm events. Stormwater grab samples were taken …

Water Quality Analysis Of Ecoroof Runoff In Portland, Pranoti P. Deshmukh

Civil and Environmental Engineering Master's Project Reports

Portland, Oregon is internationally recognized for its implementation of sustainable stormwater management technologies. Ecoroof is one of the sustainable solutions to reduce stormwater runoff which also provides multiple environmental benefits. However, very little is known about the impact of ecoroofs on water quality of roof runoff. Stormwater runoff carries a significant amount of pollutants, which, if it directly enters a stream or river, degrades water quality and severely harms aquatic life.

This study evaluates the trends in the long-term water quality data from ecoroofs and conventional roofs in the Portland area. Mann Kendall trend test was used to detect the …

A Network Approach To Complex Problems: Understanding Collaborative Governance In Watershed Management, Allison Daniel

Hatfield Graduate Journal of Public Affairs

The complexity of current environmental problems poses a challenge to the field of public management. With multiple stressors acting on the earth’s natural systems, the likelihood that complex environmental problems will persist is undeniable. Traditional approaches to such problems follow a top-down method, often useful for problem management within public policy; however, it proves too rigid when considering the complexity of environmental policy. Recent literature points to the use of collaboration and coordination in addressing complex problems, whereby stakeholders accumulate knowledge and resources across a variety of fields. One such method is network governance, identified as a problem-solving approach capable …

Attitudes, Behavior, And Archetypes In The Clackamas River Basin: A Model Of Water Customer Analysis And Outreach For Watershed Protection And Conservation, Daniel Close Larson

Dissertations and Theses

Fresh water resources around the globe are under threat of diminishing supply and quality due to rapid population growth, climate change, drought, and waste. This dissertation aims to address the protection of fresh water at the source, the tap, and how water customer attitudes influence protection and conservation using a watershed-wide lens. Using the Clackamas River Watershed which resides within the Portland Metropolitan Area (PMA), I seek to investigate water customer attitudes towards a source water protection program and their willingness to pay to support such an endeavor, attitudes and behaviors that result in household water conservation, and an exploration …

Scenes From The Swale: Investigating Spatial And Temporal Dimensions Of Nitrogen Cycling In Urban Stormwater Bioretention Facilities, Erin Nicole Looper

Dissertations and Theses

Urban development is transforming landscapes at unprecedented rates. Human activities and landscape modifications associated with urbanization extensively increase hydrologic demands and modify natural hydrologic systems; consequently, population growth occurring in urban areas increases pressure on water resources. Urban aquatic ecosystems are vulnerable to impacts associated with increased connectivity with urban surfaces and hydrologic changes that initiate long-term changes in receiving waterbodies. Nitrogen (N) loading from urban and suburban catchments to receiving surface waters can lead to impairment of aquatic ecosystems and is a concern in many cities with water quality issues. To improve urban water quality, cities are increasingly adopting …

Quantifying Increased Ground Water Demand From Prolonged Drought In The East African Rift Valley, Evan A. Thomas, Joseph A. Needoba, Doris Kaberia, John Butterworth, Emily C. Adams, Phoebe Oduor, Denis Macharia, Multiple Additional Authors

OHSU-PSU School of Public Health Faculty Publications and Presentations

Millions of people in the arid regions of Kenya and Ethiopia face water scarcity and frequent drought. Water resource forecasting and reliable operation of groundwater distribution systems may improve drought resilience. In this study, we examined three remote sensing data sets against in-situ sensor-collected groundwater extraction data from 221 water points serving over 1.34 million people across northern Kenya and Afar, Ethiopia between January 1, 2017 and August 31, 2018. In models containing rainfall as a binary variable, we observed an overall 23% increase in borehole runtime following weeks with no rainfall compared to weeks preceded by some rainfall. Further, …

Process-Based Modeling Of The Dairy Mckay Watershed To Inform Monitoring For Agricultural Best Management Practices, Brittany Saeman

Environmental Science and Management Professional Master's Project Reports

The project described in this paper specifically looks at the influence of land management practices on water quality, specifically total phosphorus (TP) loads in the Dairy McKay Watershed (DMW). The project is being used to inform a water quality monitoring plan for the Oregon DEQ via outputs from a SWAT model. The DMW is known to have high TP levels that are linked to low dissolved oxygen levels in the Tualatin River. There is a total maximum daily load (TMDL) for the Tualatin River that specifies target TP levels coming out of the DMW, if these targets are met, the …

Analysis Of Toxic Pollutant Sources And Characteristics Contributing To Water Quality Impairments In The Willamette River Basin, Melinda Borgens

Environmental Science and Management Professional Master's Project Reports

Point and nonpoint sources contribute toxic pollutants to surface waters, degrading water quality and impairing aquatic and human life. As of 2012, 51 stream segments totaling approximately 6,000 kilometers (3,750 miles) in Oregon’s Willamette River Basin (the Basin) were listed as impaired on the Clean Water Act's (CWA) Section 303(d) list with 48 toxic pollutants. These toxic pollutants exceed the Oregon Department of Environmental Quality's (DEQ) state water quality standards, requiring Total Maximum Daily Loads (TMDLs) to restore water quality and protect beneficial uses. Identifying toxic pollutant point and nonpoint sources, and the total loads a waterbody receives, are critical …

A Cost-Benefit Analysis Of Livelihood, Environmental And Health Benefits Of A Large Scale, Christina K. Barstow, Randall Bluffstone, Kyle Silon, Karl Linden, Evan Thomas

Economics Faculty Publications and Presentations

Public health interventions targeting contaminated drinking water and indoor air pollution may help to reduce two of the leading causes of death among children under 5 in Rwanda - diarrhea and pneumonia. These interventions also have the potential to provide economic benefits, including reduction in expenditures on fuelwood and time spent on fuelwood collection, environmental benefits through reductions in deforestation and greenhouse gas emissions, and additional economic benefits attributable to health impacts. We evaluate one such large scale intervention, the Tubeho Neza program in Western Rwanda using a cost-benefit analysis. This paper estimates monetized program benefits related to fuelwood savings, …

Effects Of Water Level Fluctuation On Thermal Stratification In A Typical Tributary Bay Of Three Gorges Reservoir, China, Juxiang Jin, Scott Wells, Defu Liu, Guolu Yang, Senlin Zhu, Jun Ma, Zhengjian Yang

Civil and Environmental Engineering Faculty Publications and Presentations

Xiangxi River is a typical tributary of Three Gorges Reservoir (TGR) in China. Based on field observations in 2010, thermal stratification was significant in most months of the year. Through field data analysis and numerical simulations, the seasonal and spatial variation of thermal stratification as related to the impact of the operation of TGR were investigated. Thermal stratification was most pronounced from April to September in the Xiangxi River tributary. Air temperature (AT) and water level (WL) were the two dominant variables impacting thermal stratification. AT affected the surface water temperature promoting the formation of thermal stratification, and high WLs …