Hydrology Commons^™

Annual Outflow Of Water From Nebraska, 1950 - 2010, S. Olafsen-Lackey

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Implications Of Surface Runoff Recharge In Semi-Arid Regions On Groundwater Sustainability, Omar M. Al-Qudah

Open Access Theses & Dissertations

Amargosa Desert, Nevada regional groundwater studies show that the surface runoff infiltration occurring in the arroyos following runoff producing storms, and this infiltration is considered to be a major source of groundwater recharge. Groundwater infiltration through alluvium was investigated in the Amargosa Desert using borehole drill cuttings, groundwater chemistry, and applying a novel method for collecting runoff water. The sampling process included sediment, precipitation, and runoff water. In total, 176 runoff, 182 sediment, and 45 precipitation samples were collected between January, 2009 and January, 2011.Water chemistry, chloride concentrations, and stable isotopes of water collected from specially designed runoff samplers, placed …

Estimating Groundwater Discharge In The Oligohaline Ecotone Of The Everglades Using Temperature As A Tracer And Variable-Density Groundwater Models, Victora Spence

USF Tampa Graduate Theses and Dissertations

Recent research suggests that brackish, marine-derived groundwater up-wells in the oligohaline ecotone of the coastal Everglades, bringing with it phosphorus to an otherwise phosphorus-poor environment. The purpose of this study is to estimate the rates and timing of the groundwater discharge by using variable-density groundwater models constructed, calibrated, and validated with field measurements of hydraulic head and surface and subsurface temperature. Modeled groundwater discharge rates ranged from 5.4E-04 mm/day in August to -1.3E-03 mm/day in June for Shark Slough and 4.8E-01 mm/day in June to -1.4E-01 mm/day in January for Taylor Slough, where positive values imply groundwater discharge and negative …

Pce Groundwater Quality Assessment Of The University Of Northern Iowa Campus Area, Brian Gedlinske

Graduate Research Papers

Perchloroethylene (PCE), is a colorless, nonflammable, and relatively insoluble chlorinated solvent once widely used for dry cleaning and metal degreasing operations. Because of its past widespread use, poor solvent management practices, and environmental persistence, PCE is a common contaminant found in groundwater supplies. Potential health concerns include liver problems and increased cancer risk.

This research paper presents the findings of an effort to better characterize the spatial, temporal, and transport attributes of a PCE groundwater plume that exists within the Devonian aquifer underlying the University of Northern Iowa campus and the surrounding area in Cedar Falls, Iowa. Findings reveal the …

Fate Of Stable Isotope Label During Predation Of 15N-Tagged Wild-Type Escherichia Coli By Protozoa, Ashley M. Barton

University of Kentucky Master's Theses

Currently, bacterial movement in karst aquifers is not well understood. Use of stable isotopes to label non-pathogenic Escherichia coli as a particulate groundwater tracer in karst systems has been examined in previous studies. Loss of the stable isotope signal is anticipated in traces greater than 500 m in length. Potential loss of ¹⁵N due to predation by protozoa was examined. Filter-sterilized water from Royal Spring in Georgetown, Kentucky, was inoculated with a mixture of either Tetrahymena pyriformis or Colpoda steinii and ¹⁵N-enriched E. coli and stored in the dark at 14°C. Samples were analyzed for their nitrogen isotope …

Arctic Sea-Ice Melt In 2008 And The Role Of Solar Heating, Donald K. Perovich, Jacqueline A. Richter-Menge, Kathleen F. Jones, Bonnie Light

Dartmouth Scholarship

There has been a marked decline in the summer extent of Arctic sea ice over the past few decades. Data from autonomous ice mass-balance buoys can enhance our understanding of this decline. These buoys monitor changes in snow deposition and ablation, ice growth, and ice surface and bottom melt. Results from the summer of 2008 showed considerable large-scale spatial variability in the amount of surface and bottom melt. Small amounts of melting were observed north of Greenland, while melting in the southern Beaufort Sea was quite large. Comparison of net solar heat input to the ice and heat required for …

Modeling Direct Runoff Hydrographs With The Surge Function, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

A surge function is a mathematical function of the form f(x)=ax^pe^-bx. We simplify the surge function by holding p constant at 1 and investigate the simplified form as a potential model to represent the full peak of a stream discharge hydrograph. The previously studied Weibull and gamma distributions are included for comparison. We develop an analysis algorithm which produces the best-fit parameters for every peak for each model function, and we process the data with a MATLAB script that uses spectral analysis to filter year-long, 15-minute, stream-discharge data sets. The filtering is necessary to locate the …