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Full-Text Articles in Environmental Sciences
Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer
Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer
School of Natural Resources: Dissertations, Theses, and Student Research
Streambed hydraulic conductivity (K) is known to be spatially and temporally heterogeneous, but few attempts to understand the controls on temporal variability have been made. This study documents temporal K transience and demonstrates how hydraulic, geophysical, and sedimentological methods can be combined to understand the processes that give rise to changes in streambed K. Falling head permeameter tests and slug tests were conducted to determine vertical K (Kv) and K (slug test K), respectively. These tests were repeated three times over a twelve-week period on the same grid at a depth of 0.5 …
Determining Scaphirhynchus Sturgeon Population Demographics And Dynamics: Implications For Range-Wide Management, Recovery, And Conservation, Martin J. Hamel
Determining Scaphirhynchus Sturgeon Population Demographics And Dynamics: Implications For Range-Wide Management, Recovery, And Conservation, Martin J. Hamel
School of Natural Resources: Dissertations, Theses, and Student Research
Sturgeons (Acipenseridae) have experienced world-wide declines as a result of anthropogenic effects such as over-harvest, habitat degradation, altered flow regimes, and pollution. Nearly all European and Asian sturgeon species have experienced population declines and have subsequently been classified as either threatened or endangered. North American sturgeons have experienced a similar plight in that all eight native sturgeon species are listed as endangered, threatened, or of special concern. Direct linkages between North American sturgeon declines and anthropogenic effects are difficult to assess due to scale considerations, fluctuating environmental conditions, difficulty in capture, and the interaction of all these effects. To recover, …
Climatic Controls On The Summertime Energy Balance Of A Thermokarst Lake In Northern Alaska: Short-Term, Seasonal, And Interannual Variability, Brittany L. Potter
Climatic Controls On The Summertime Energy Balance Of A Thermokarst Lake In Northern Alaska: Short-Term, Seasonal, And Interannual Variability, Brittany L. Potter
School of Natural Resources: Dissertations, Theses, and Student Research
Shallow, thermokarst lakes that develop atop permafrost are a prominent landscape feature on the Arctic Coastal Plain (ACP) of northern Alaska. The ACP is vulnerable to ongoing climate change and landscape modification, as thousands of thaw lakes and ponds are impacted by changes in temperature, precipitation, thawing permafrost, and human activity. Although summer in the Arctic is short, incoming solar radiation and lake evaporation are relatively high, and both factors play a significant role in the landscape water balance. Furthermore, lake evaporation is anticipated to increase as the ice-free season lengthens and water temperatures become warmer. To improve our understanding …
Biogeochemical Behavior Of Dissolved Arsenic And Uranium Concentrations In Public Water Supply Wells, Kevin J. Mcvey
Biogeochemical Behavior Of Dissolved Arsenic And Uranium Concentrations In Public Water Supply Wells, Kevin J. Mcvey
School of Natural Resources: Dissertations, Theses, and Student Research
Public water supply (PWS) wells currently contain dissolved uranium concentrations above the federally mandated maximum contaminant level (MCL) of 30 ppb (parts per billion) and dissolved arsenic concentrations above the 10 ppb MCL. Both uranium and arsenic are known to cause various forms of cancer in humans. Variations in total uranium concentrations in PWS wells in Nebraska indicate a relationship to the duration and rate of pumping in specific wells. Although total arsenic concentrations show some variability over time in specific wells, the relationship to pumping is not as clear. Previous studies show that iron and sulfur bacteria present in …