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Full-Text Articles in Earth Sciences

Quantifying Groundwater-Surface Water Interactions To Improve The Outcomes Of Human Activities, Ryan Parish Gordon Dec 2013

Quantifying Groundwater-Surface Water Interactions To Improve The Outcomes Of Human Activities, Ryan Parish Gordon

Dissertations - ALL

Interactions between surface water and groundwater impact both the quality and quantity of water resources. This dissertation is focused on the interactions between surface water in streams and groundwater in hyporheic zones and shallow fluvial aquifers, and how human beings influence these interactions and are influenced by them. The three chapters of this dissertation span scales from cm to km and locations from Upstate New York to the Peruvian Andes, but are united by the goal to improve the scientific understanding of groundwater-surface water interactions (GWSWI) using novel techniques, in order to improve the outcomes of human activities for people …


Hydrogeologic Variations Across A Barrier Island That Influence Inter-Dune Wetlands False Cape State Park, Virginia, Matthew Collier Richardson Oct 2013

Hydrogeologic Variations Across A Barrier Island That Influence Inter-Dune Wetlands False Cape State Park, Virginia, Matthew Collier Richardson

OES Theses and Dissertations

False Cape State Park in southeastern Virginia Beach, Virginia contains a transgressive barrier island complex. Inter-dune swales located on the eastern coast of the barrier island contain soils that experience hydric conditions. However, these swales lack the prolonged presence of hydric soil indicators that are necessary for a site to be officially recognized as a jurisdictional wetland. The appearance and subsequent disappearance of redoximorphic wetland soil features in the young, sandy soils of the inter-dune swales here may stem from changes in the patterns of groundwater recharge and discharge across the island. These soils are being monitored by the Mid …


Geochemistry And Inorganic Carbon Transport Of A Glacial Till Drumlin At A Road Salt Facility, Houbao Li Sep 2013

Geochemistry And Inorganic Carbon Transport Of A Glacial Till Drumlin At A Road Salt Facility, Houbao Li

Open Access Dissertations

Investigations were conducted at a salt/premix storage facility lying on top of a glacial drumlin near the coastline in eastern Massachusetts, to characterize salt contaminated groundwater. Groundwater hydrogeochemical variations at different depths were determined based on ten years of monthly or quarterly water quality data from 54 monitoring wells. Groundwater was grouped in three water categories – shallow, middle and deep. Hydrogeochemical characterization indicates that the dominant water types are Na-Cl, Na-Ca-Cl and Ca-HCO3 from the shallow to deep water group. Rock weathering is the dominant hydrogeochemical process for deep water group, whereas salt water percolation and cation exchange control …


Using Hydrologic Measurements To Investigate Free Phase Gas In A Maine Peatland, Usa, Christiaan Bon May 2013

Using Hydrologic Measurements To Investigate Free Phase Gas In A Maine Peatland, Usa, Christiaan Bon

Electronic Theses and Dissertations

Northern Peatlands cover more than 350 million ha (~3 percent of Earth’s surface) and are an important source of methane (CH4) and other biogenic gases contributing to climate change. Free phase gas (FPG) accumulation and episodic release has recently been recognized as an important mechanism for biogenic gas flux from peatlands. It is likely that gas production and groundwater flow are interconnected in peatlands: groundwater flow influences gas production by regulating geochemical conditions and nutrient supply available for methanogenesis while FPG influences groundwater flow through a reduction in peat permeability and by creating excess pore fluid pressures. Water samples collected …


Quantifying The Relationship Among Ground Penetrating Radar Reflection Amplitudes, Horizontal Sub-Wavelength Bedrock Fracture Geometries, And Fluid Conductivities, Carolyn Morgan Tewksbury-Christle May 2013

Quantifying The Relationship Among Ground Penetrating Radar Reflection Amplitudes, Horizontal Sub-Wavelength Bedrock Fracture Geometries, And Fluid Conductivities, Carolyn Morgan Tewksbury-Christle

Masters Theses

Accurate characterization of subsurface fractures is indispensible for contaminant transport and fresh water resource modeling because discharge is cubically related to the fracture aperture; thus, minor errors in aperture estimates may yield major errors in a modeled hydrologic response. Ground penetrating radar (GPR) has been successfully used to noninvasively estimate fracture aperture for sub-horizontal fractures at outcrop scale, but limits on vertical and horizontal resolution are a concern. Theoretical formulations and field tests have demonstrated increased GPR amplitude response with the addition of a saline tracer in a sub-millimeter fracture; however, robust verification of existing theoretical equations without an accurate …


The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart May 2013

The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart

UNLV Theses, Dissertations, Professional Papers, and Capstones

As drought conditions spread across the United States, concerns over water supplies, water use, and water management policies are growing and possible contributing environmental factors are continually being scrutinized. This thesis examines Death Valley as an analog for Southern Nevada and utilizes NASA EOS data, combined with ancillary climate data, to assess the effect of decadal climate variability on groundwater storage in the Death Valley area. Historical climate data, combined with satellite imagery observations, were compiled and calculated for analyses. Conclusions derived from statistical analyses infer trends between GRACE (Gravity Recovery and Climate Experiment) satellite data and fluctuating levels of …


Post-Emplacement Leaching Behaviors Of Nano Zero Valent Iron Modified With Carboxymethylcellulose Under Simulated Aquifer Conditions, Leslie Lavinia Williams Jan 2013

Post-Emplacement Leaching Behaviors Of Nano Zero Valent Iron Modified With Carboxymethylcellulose Under Simulated Aquifer Conditions, Leslie Lavinia Williams

Browse all Theses and Dissertations

Nanoscale particles of zero valent iron stabilized with carboxymethylcellulose (CMC-nZVI) have been shown to degrade chlorinated hydrocarbons efficiently in bench-scale investigations. The remediation of contaminated sites by subsurface injection of stabilized nZVI in a slurry form has been investigated at pilot scale and field scale with conflicting results concerning transport of stabilized nZVI and its long-term stability for in situ degradation of chlorinated hydrocarbons. Changes in the hydraulic conductivity in porous media have also been reported following injection of stabilized nZVI slurry in both large tank experiments and in field studies. This study investigated the leaching behavior of CMC-nZVI post-emplacement …


Temporal And Spatial Variations In The Subsurface Salinity Of Lake Charles, Louisiana : An Investigation Of Saline Sources, Alexandria Suding Jan 2013

Temporal And Spatial Variations In The Subsurface Salinity Of Lake Charles, Louisiana : An Investigation Of Saline Sources, Alexandria Suding

LSU Master's Theses

One of the most pressing issues facing groundwater managers is saltwater intrusion. In coastal Louisiana this issue is especially prevalent. One location that is currently threated by saltwater intrusion is the industrial area of Lake Charles, Louisiana, where three high chloride areas have been detected within the underlying Chicot aquifer. Three sand units of the Chicot aquifer are present in Lake Charles: the 200-foot (200’) sand, the 500’ sand, and the 700’ sand. Groundwater with elevated chloride concentrations was first noticed by industries in the early 1970s. An initial investigation determined that the northern and southern bodies had formed by …