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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Estimating The Water Quality Condition Of River And Lake Water In The Midwestern United States From Its Spectral Characteristics, Jing Tan
Open Access Dissertations
This study focuses on developing/calibrating remote sensing algorithms for water quality retrieval in Midwestern rivers and lakes. In the first part of this study, the spectral measurements collected using a hand-held spectrometer as well as water quality observations for the Wabash River and its tributary the Tippecanoe River in Indiana were used to develop empirical models for the retrieval of chlorophyll (chl) and total suspended solids (TSS). A method for removing sky and sun glint from field spectra for turbid inland waters was developed and tested. Empirical models were then developed using a subset of the field measurements with the …
Consequences Of Short-Term Water Temperature Variability To Fish: Current And Future Climate Change Impacts, David P. Coulter
Consequences Of Short-Term Water Temperature Variability To Fish: Current And Future Climate Change Impacts, David P. Coulter
Open Access Dissertations
Water temperature has a profound influence on aquatic ectotherms by affecting all aspects of biological organization; from chemical and molecular functioning to whole-organism and population-level impacts. Natural processes and anthropogenic activities can create conditions where temperatures vary greatly through space and time. While exposure to temperature changes lasting ≥ 24 hours have been examined in some species, it is unclear how more rapid (< 24 hours; sub-daily) thermal fluctuations affect aquatic ectotherms. I used a combination of field observations, laboratory experiments, and modeling simulations to understand: 1) how habitat quality of aquatic ectotherms is affected in thermally dynamic environments; 2) the role of sub-daily temperature fluctuations on growth, survival, and stress responses in juvenile and adult fish; 3) how fish early life stages are affected by sub-daily temperature fluctuations; and 4) what impact thermally dynamic environments have on a model species at a population-level. A model quantifying habitat quality around power plant thermal discharges indicated that elevated and variable discharge temperatures affected habitat quality over a relatively small spatial area for aquatic ectotherms. Models examining elevated temperatures representing climate warming showed that the effects of industrial discharges and climate warming could have an interactive effect on habitat quality by increasing the spatial area and duration over which industrial thermal effluents impact aquatic ectotherms. Laboratory experiments indicated that closely related fishes can respond differently to the same sub-daily temperature fluctuations. Yellow perch (Perca flavescens) had higher consumption and growth under sub-daily temperature fluctuations but developed skin lesions; an indication of thermal stress. In contrast, these same fluctuations reduced growth in physiologically similar walleye (Sander vitreus) …
Uncertainty Quantification And Calibration Of Physical Models, Xian He
Uncertainty Quantification And Calibration Of Physical Models, Xian He
Open Access Dissertations
An ecosystem model is a representation of a real complex ecological system, and is usually described by sophisticated mathematical models. Terrestrial Ecosystem Model (TEM) is one of the ecosystem models, that describes the dynamics of car- bon, nitrogen, water and other vegetation related variables. There are uncertainties in the TEM which are attributed to inaccurate input data, insufficient knowledge of the parameters, inherent randomness and simplification of the physical model. Quantification of uncertainty of such an ecosystem model is computationally very heavy. Bayesian calibration method has been used as an efficient way to calibrate and quantify uncertainties of the computer …
Biology And Ecology Of Bigheaded Carp In An Invaded Ecosystem, Alison Adele Coulter
Biology And Ecology Of Bigheaded Carp In An Invaded Ecosystem, Alison Adele Coulter
Open Access Dissertations
Globally, the homogenization of species has become a threat to biodiversity. As species are transported around the world, a portion of these species, released intentionally or accidentally, may become invasive and can produce negative impacts. Great effort has been invested into early identification and prevention of invasions as these are considered less expensive than managing an invasion. Unfortunately, species may exhibit varying characteristics across ecosystems, and so their behavior and potential survival in a new environment may be difficult to predict. Therefore, I examined trends in the biology and behavior of invasive fishes, including the plasticity surrounding these and how …
International Water And Food Security Development: Performance Evaluation And Assessment Of Research Needs At Multiple Scales, Caitlin Anne Grady
International Water And Food Security Development: Performance Evaluation And Assessment Of Research Needs At Multiple Scales, Caitlin Anne Grady
Open Access Dissertations
Water and food security remain the top development challenges of the decade, and perhaps the century. Since the Millennium Development Goals were established in 2000, billions of people have obtained access to more food, better nutrition, improved water, and basic sanitation facilities worldwide. This progress has been accomplished through the dedication of international organizations, non-governmental organizations, country-level governments, private corporations, and individuals at international, regional, and local scales. Truly tremendous strides have been made in water and food provisioning for humans worldwide. These past two decades have also seen the largest population growth on record, the highest rates of childhood …
Food Security In The Free State Province: Meaning Making As Democratic Agency, Jacqueline Del Valle Hanoman Ambrosio
Food Security In The Free State Province: Meaning Making As Democratic Agency, Jacqueline Del Valle Hanoman Ambrosio
Open Access Dissertations
People's stories are powerful means of explaining their realities, for their narratives reveal what meanings they make of the situations they are living, how they face these situations and what strategies they formulate to overcome them. Their meaning making is one of the most powerful tools of their agency, and this is what this study reveals. In it, I tell the stories of people in the Free State Province, South Africa, who face food insecurity within abundance, and their critical consciousness and agency as they struggle to survive in their democracy. Poverty is a rawness...Poverty is struggle... Poverty is shame...these …
Spatial Analysis Of Passenger Vehicle Use And Ownership And Its Impact On The Sustainability Of Highway Infrastructure Funding, Matthew Volovski
Spatial Analysis Of Passenger Vehicle Use And Ownership And Its Impact On The Sustainability Of Highway Infrastructure Funding, Matthew Volovski
Open Access Dissertations
Across the United States, the sustainability of highway funding is at risk due to increasing need and uncertainty in the factors that drive revenue. Past studies on highway funding sustainability have identified that the root cause of changing highway revenue are the shifts in social demographics and economic characteristics. Unfortunately, from the revenue perspective (the focus of this dissertation), the ability of previous research to account for these factors has been rather limited in two ways; first, the inability to accurately assess current regional vehicle use (a typical prerequisite for statistical modeling of highway revenues) due to difficulties associated with …