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Full-Text Articles in Physical Sciences and Mathematics

Long-Term Variation Of Summer Phytoplankton Communities In An Urban Lake In Relation To Lake Management And Climate Conditions, Yuan Xiao Grund Dec 2018

Long-Term Variation Of Summer Phytoplankton Communities In An Urban Lake In Relation To Lake Management And Climate Conditions, Yuan Xiao Grund

Dissertations and Theses

Eutrophication is one of the primary factors causing harmful cyanobacteria blooms in freshwater lakes; climate change such as warmer temperature can potentially further increase both frequency and intensity of blooms. This study investigated the long-term changes in water quality and summer phytoplankton assemblages in Oswego Lake, OR, in relation to lake management practices (e.g., hypolimnetic aeration and alum treatments), as well as climatic and regional meteorological conditions. Both water quality and phytoplankton assemblages were sampled biweekly during summer seasons between 2001 and 2013. The concentrations of total phosphorus (TP), soluble reactive phosphorus (SRP) and total nitrogen (TN) decreased 66%, 93% …


Using Wetlands To Prevent The Surface Accumulation Of Aphanizomenon Flos-Aquae From Upper Klamath Lake, Arick Christopher Rouhe Aug 2018

Using Wetlands To Prevent The Surface Accumulation Of Aphanizomenon Flos-Aquae From Upper Klamath Lake, Arick Christopher Rouhe

Dissertations and Theses

The ability to regulate buoyancy (sinking and floating) using cellular gas vesicles is a unique characteristic that allows many common bloom-forming cyanobacteria to accumulate at water surfaces and dominate systems. Typical control and management strategies include nutrient manipulation and phosphorus reduction, which are effective but do not reduce the advantage of buoyancy control. Since buoyancy control is based upon a mechanism that is driven by photosynthesis along with environmental conditions that trigger vesicle formation and ion exchange, buoyancy regulation can be influenced by manipulating extracellular conditions. In this study I manipulated extracellular conditions using wetland water and additions of potassium, …


Mapping Water Availability, Cost And Projected Consumptive Use In The Eastern United States With Comparisons To The West, Vincent C. Tidwell, Barbie D. Moreland, Calvin R. Shaneyfelt, Peter Kobos Jan 2018

Mapping Water Availability, Cost And Projected Consumptive Use In The Eastern United States With Comparisons To The West, Vincent C. Tidwell, Barbie D. Moreland, Calvin R. Shaneyfelt, Peter Kobos

Environmental Science and Management Faculty Publications and Presentations

The availability of freshwater supplies to meet future demand is a growing concern. Water availability metrics are needed to inform future water development decisions. Furthermore, with the help of water managers, water availability was mapped for over 1300 watersheds throughout the 31-contiguous states in the eastern U.S. complimenting a prior study of the west. The compiled set of water availability data is unique in that it considers multiple sources of water (fresh surface and groundwater, wastewater and brackish groundwater); accommodates institutional controls placed on water use; is accompanied by cost estimates to access, treat and convey each unique source of …


Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu Jan 2018

Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu

Environmental Science and Management Faculty Publications and Presentations

Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after …