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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise
Evaluating A Measure-Calculate Method For Determining Sediment Oxygen Demand In Lakes, Adrian Beirise
Graduate Theses and Dissertations
A steady-state mass diffusion model used with simple measurable and calculable inputs for determining sediment oxygen demand (SOD) is compared to an intact core incubation (ICI) SOD method using samples from three lakes. The mass diffusion model coupled with inputs is known as the measure-calculate method (M-C) and is a potential alternative to existing methods for measuring SOD which are more complex, time-consuming, and costly. The M-C method requires inputs for volumetric sediment oxygen uptake (Ṅsed), sediment density and porosity, and water properties. Ṅsed was determined by suspending sediment in oxygen-saturated water with a DO probe and determining the steady …
Optical Water Quality And Human Perceptions Of Rivers, Amie West
Optical Water Quality And Human Perceptions Of Rivers, Amie West
Graduate Theses and Dissertations
Understanding water quality dynamics in recreational rivers is integral in shaping management strategies that maintain ecosystem health, perceived value and appeal, and regional economic significance in a changing environment. Optical water quality describes the behavior of light in water as governed by its physical and chemical composition, and is among the strongest influences on human perceptions of water quality. Ethnohydrology is the study of culturally constructed knowledge and understanding of water. This work is the culmination of an interdisciplinary approach to water resources research—integrating optical water quality and ethnohydrology methods to recognize the intersection between measured water quality and visible …
Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson
Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson
Graduate Theses and Dissertations
Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …
Agro-Climatic Change, Crop Production And Mitigation Strategies-Case Studies In Arkansas, Usa And Kenya, John Westley Magugu
Agro-Climatic Change, Crop Production And Mitigation Strategies-Case Studies In Arkansas, Usa And Kenya, John Westley Magugu
Graduate Theses and Dissertations
Although climate change impacts vary geographically and temporally, studies at local levels are not readily available for stakeholders to better understand how their local communities would be affected and what remedial measures could be more effective in their local contexts. This dissertation has examined climate change and its impacts in two different local contexts: eastern Arkansas in the USA and Nyando in Kenya. The first part of this dissertation develops agro-meteorological indicators and examines the relationship between agro-meteorological indicators and crop yields in eastern Arkansas between 1960 and 2014. Results reveal that temperature based indicators were more strongly correlated to …
A Method Comparison And Stressor-Response Experimental Study Of Nitrogen And Phosphorus Impacts To Periphyton In Ozark Streams, Ashley Renee Rodman
A Method Comparison And Stressor-Response Experimental Study Of Nitrogen And Phosphorus Impacts To Periphyton In Ozark Streams, Ashley Renee Rodman
Graduate Theses and Dissertations
Stream bioassessment is important for understanding algal-nutrient relationships and the development of scientifically defensible numeric nutrient criteria. However, multiple methods of periphyton data collection are currently used, and little is known about the comparability of resulting datasets. Literature also suggests other factors besides nutrients (i.e. variable grazing, light, and flow) can confound algal-nutrient relationships. A one-year method comparison study and 31-day algal biomass-nutrient manipulative experiment were conducted in the southern Ozarks of Arkansas. The method comparison study was implemented using two common bioassessment procedures (whole-surface and delimiter-reduced periphyton removal) to assess the potential for combining datasets. During the manipulative experiment, …
Reducing Nutrient Runoff From Poultry Production Facilities Using Locally-Sourced Iron And Aluminum Byproducts, Sheri Lynn Herron
Reducing Nutrient Runoff From Poultry Production Facilities Using Locally-Sourced Iron And Aluminum Byproducts, Sheri Lynn Herron
Graduate Theses and Dissertations
Phosphorus (P) inputs to fresh waters can accelerate the eutrophication process. Agricultural nutrient runoff has been shown to be a contributor of P and nitrogen (N). Broiler production areas were evaluated for their potential to contribute P and N to runoff. Broiler house dust (BHD) samples were analyzed and compared to broiler litter (BL), rainfall simulations were conducted on plots adjacent to broiler house fans to evaluate nutrient enrichment in runoff from deposited dust, and runoff was automatically sampled at two culverts draining the land around broiler houses. Following this, an on-farm byproduct containment and nutrient removal structure was designed …
The Consciousness Of Water: Narrative Flows, Environmental Change, And The Voice Of Yemen, Tricia Nellessen
The Consciousness Of Water: Narrative Flows, Environmental Change, And The Voice Of Yemen, Tricia Nellessen
Graduate Theses and Dissertations
Icebergs are melting in the Arctic. The Gulf of Mexico is warming and producing hurricanes such as Katrina. The delta of the southern United States is drying. And, Yemen will be the first country in modern history to experience a lack of accessible ground water, as soon as 2017 possibly. Yemen's situation has been tracked by scholars and governments since the 1960s. Despite this fact, cities have expanded in Yemen and the population has increased its use of water while little has been invested in desalination or infrastructure to offset growth. Climate change has affected humans for thousands of years; …
A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh
A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh
Graduate Theses and Dissertations
This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …
Nutrient Dynamics In Stormwater Runoff From Green Roofs With Varying Substrate, John Michael Fohner
Nutrient Dynamics In Stormwater Runoff From Green Roofs With Varying Substrate, John Michael Fohner
Graduate Theses and Dissertations
One major concern with urban development is the increasing amount of stormwater runoff from large expanses of impervious surfaces. These impervious surfaces reduce the ability of stormwater to infiltrate into the soil and eventually groundwater, which leads to greater amounts of surface runoff. Green technology serves as a viable solution to many of the environmental problems presented by modern development. Fifteen mock, extensive green roofs were built in the fall of 2008 at the Watershed Research and Education Center in Fayetteville, Arkansas. The goals of this project were to (1) measure the amount of stormwater runoff from varying treatments and …