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Design And Implementation Of An Inverse Modeling Framework Using The Method Of Anchored Distributions, Carlos Andres Osorio Murillo
Design And Implementation Of An Inverse Modeling Framework Using The Method Of Anchored Distributions, Carlos Andres Osorio Murillo
Theses and Dissertations
Estimation of spatial random fields (SRFs) such as transmissivity or porosity is required for predicting groundwater flow and subsurface contaminant movement. Similarly, distributed parameter fields such as terrain roughness and evapotranspiration coefficients are required by other areas of environmental and earth sciences modeling. This dissertation presents an inverse modeling framework for characterizing SRFs called MAD#, which is an end-user software implementation of the Bayesian inverse modeling technique Method of Anchored Distributions (MAD). The MAD# framework allows modelers to “wrap” existing simulation modeling tools using an extensible driver architecture that exposes model parameters to the inversion engine. A compelling aspect of …
Comparative Recharge Rates Of Isolated And Riverine Wetlands, Chenille Hargrove Williams
Comparative Recharge Rates Of Isolated And Riverine Wetlands, Chenille Hargrove Williams
Theses and Dissertations
Isolated wetlands have a slightly depressed topography surrounded by an upland area. There is no direct surface water connection, as with riverine wetlands; however, there is a groundwater connection that allows isolated wetlands to have similar hydrologic functions to riverine wetlands. This study sought to compare surficial aquifer groundwater recharge rates of several isolated and riverine wetlands in the Coastal Plain of the Carolinas by evaluating soil characteristics, water table fluctuations, and precipitation from January 2012 - September 2012. Data analysis indicated no significant difference in mean recharge rates between the isolated and riverine wetlands at each study site. Whereas …
Development Of Novel Bioelectrochemical Systems For In Situ Nitrate Removal From Groundwater, Yiran Tong
Development Of Novel Bioelectrochemical Systems For In Situ Nitrate Removal From Groundwater, Yiran Tong
Theses and Dissertations
This study aims to develop new approaches for in situ nitrate removal from groundwater by using bioelectrochemical systems (BES). BESs employ bioelectricity generated from organic compounds to drive nitrate moving from groundwater into the electrode chamber and reduce nitrate to nitrogen gas by heterotrophic denitrification. In first phase experiments, nitrate ions were driven into the anode chamber of a de-coupled reactor, whose electrode chambers were separated, where heterotrophic denitrification took place with organic reduction. It was proved that by applying additional electrical potential at 0.8V, the reactor could achieve highest removal rate of 208.2±13.3 g NO3--N/m3/d, when initial nitrate concentration …
Development Of An Integrated Suite Of Methods To Reduce Computational Effort In Groundwater Modeling Validation And Testing, Jacqueline Pettway
Development Of An Integrated Suite Of Methods To Reduce Computational Effort In Groundwater Modeling Validation And Testing, Jacqueline Pettway
Theses and Dissertations
A suite of tools to reduce the computational effort in groundwater modeling validation and testing has been developed. The work herein explores reduction of computational effort via smart adaptivemeshing, optimization techniques, which require fewer model calls, and the development of surrogate models. Adaptive meshing reduces the computational domain by allowing for mesh refinement in areas of interest determined dynamically by the model through error indicators instead of requiring a priori knowledge or a posteriori determination and rebuilding of the computational domain. As the areas of interest change with the physics, the refinement is removed to lower computational time by using …
Development Of An Interactive Model Predicting Climatological And Cultural Influences On Annual Groundwater Volume In The Mississippi Delta Shallow Alluvial Aquifer, Tia Leni Merrell
Theses and Dissertations
Water volume in the shallow alluvial aquifer in the Mississippi Delta region is subject to seasonal declines and annual fluctuations caused by both climatological variability and crop water use variations from year-to-year. The most recently documented water volume decline in the aquifer is estimated at 500,000 acreeet. Available climate, crop acreage, irrigation water use, and groundwater decline data from Sunflower County, MS are used to evaluate the climate-groundwater interactions in the Mississippi Delta region. This research produced a model that simulates the effects of climatic variability, crop acreage changes, and specific irrigation methods on consequent variations in the water volume …
Contribution Of Recharge Along Regional Flow Paths To Discharge At Ash Meadows, Nevada, Michelle Bushman
Contribution Of Recharge Along Regional Flow Paths To Discharge At Ash Meadows, Nevada, Michelle Bushman
Theses and Dissertations
Springs in the Ash Meadows, Nevada wetland area are discharging groundwater at a high volume that cannot be sustained by local, present-day precipitation and associated recharge. Previous groundwater flow models for this region have required groundwater to flow through complex geology for long distances (160km) through fractures that, in the current stress field, should be closed in many instances in the presumed flow direction. This thesis examines several possible flow paths and evaluates each flow path using chemical and isotopic signatures in the water, as well as geologic and geophysical constraints, and determines that flow from beneath the Yucca Mountain …
A Conceptual Model Of Groundwater Flow In Spring Valley, Nv, And Snake Valley, Nv-Ut, Jeremy Micheal Gillespie
A Conceptual Model Of Groundwater Flow In Spring Valley, Nv, And Snake Valley, Nv-Ut, Jeremy Micheal Gillespie
Theses and Dissertations
A geochemical study of major springs and wells in Spring Valley, Nevada, and Snake Valley, Utah-Nevada was initiated in response to the Clark, Lincoln and White Pine Counties Groundwater Development Project proposed by the South Nevada Water Authority (SNWA). Water budget estimates suggest that interbasin flow accounts for a significant portion (~25%) of the water budgets in Spring and Snake Valleys. Although interbasin flow is possible in some areas, alternative plausible explanations place significant uncertainty on water budget allocations. To examine the plausibility of local and interbasin flow paths the groundwater flow in Spring and Snake Valleys was evaluated using …
Solute Chemistry And Isotopic Investigation Of The Groundwater Flow Paths In Honey Lake Basin, Lassen County, California And Washoe County, Nevada, Rachel M. Henderson
Solute Chemistry And Isotopic Investigation Of The Groundwater Flow Paths In Honey Lake Basin, Lassen County, California And Washoe County, Nevada, Rachel M. Henderson
Theses and Dissertations
Honey Lake Basin is a large, hydrologically closed valley with two playa lakes that are separated by a low elevation sill. The Basin has a complex hydrogeologic setting, with numerous groundwater flow paths that interact with surface waters and three basic aquifers; shallow, deep, and geothermal. Thirteen flow paths; eleven cold and two thermal, are identified and the geochemical evolution of those paths are characterized by integrating solute chemistry and isotopic data. The chemical flow paths include recharge in either granitoid or volcanic terrains in the Sierra Nevada Range and the Modoc Plateau, respectively. The groundwater then flows through alluvial …
Parameter Importance Of An Analytical Model For Transport In The Vadose Zone, Tanner Hans Bushnell
Parameter Importance Of An Analytical Model For Transport In The Vadose Zone, Tanner Hans Bushnell
Theses and Dissertations
The American Society of Testing and Materials (ASTM) has established a three tier risk-based corrective action (RBCA) program for cleaning up petroleum release sites, which is supported by the Environmental Protection Agency. RBCA programs make the cleanup of spill sites more efficient by requiring additional site information only when a more accurate risk assessment is needed. For spill sites that do not pass the first tier general assessment, a Tier 2 evaluation involving site specific information and screening level models to assess the potential risk must be conducted. Screening level models generally require site specific input parameters. To increase efficiency …
Hydrogeologic Conditions Controlling Contaminant Migration From Storage Tanks Overlying Mississippi River Alluvium, Jay N (Jay Nicholas) Santucci
Hydrogeologic Conditions Controlling Contaminant Migration From Storage Tanks Overlying Mississippi River Alluvium, Jay N (Jay Nicholas) Santucci
Theses and Dissertations
Delta Store #3033 in Indianola, MS is suspected of having had a release of petroleum, which may have contaminated the underlying soil and shallow groundwater. Exploratory boring/monitoring wells were drilled on-site noting all soil formations and groundwater encountered. The soil facies encountered show a fining upward sequence, representative of a fluvial depositional environment. Soil contamination is mostly confined to the surficial soil; however, evaluation of lab data, boring logs, and cross sections suggests it is likely the contamination migrated through the surficial confining layer into the underlying strata. The hydraulic conductivity of 1.2 x 10-5 cm/sec, surficial geology consisting mostly …
The Geology And Hydrology Of The Proposed Upper Mccurtain Creek Watershed Impoundment Choctaw County, Mississippi, Leonard D (Leonard Dwight) Rawlings
The Geology And Hydrology Of The Proposed Upper Mccurtain Creek Watershed Impoundment Choctaw County, Mississippi, Leonard D (Leonard Dwight) Rawlings
Theses and Dissertations
The McCurtain Creek watershed was proposed for a large reservoir project resulting in the commissioning of this study to assess the site?s geology, hydrogeology, and surface hydrology to find whether or not the site was suitable. Data was collected from 57 geophysical logs from coal exploration boreholes to produce geologic and aquifer cross sections. A program to assess discharge identified surface hydrology characteristics of the stream at five locations. Twenty-seven geotechnical boreholes, 23 standpipe piezometers, and the data from the coal exploration were used to map the water table using ArcGIS 8.3 software. Eighteen piezometers at stream sites, used to …
Relationship Between Fault Zone Architecture And Groundwater Compartmentalization In The East Tintic Mining District, Utah, Sandra Myrtle Conrad Hamaker
Relationship Between Fault Zone Architecture And Groundwater Compartmentalization In The East Tintic Mining District, Utah, Sandra Myrtle Conrad Hamaker
Theses and Dissertations
The Eureka Lilly fault zone provides an impermeable barrier for groundwater flow in the East Tintic mining district. The fault zone separates two distinct groundwaters that have different temperatures, compositions, and potentiometric surfaces. The damage zone of the fault is an extensive network of interconnected open fractures and fault intersections that provide conduits for groundwater flow in otherwise impermeable units. The fault core breccia has been re-cemented and mineralized, which eliminates porosity in the rock by creating a thick impermeable zone, which has compartmentalized groundwaters across the fault zone. The compartmentalization of groundwater shows that fault zone variability (from strain …
Effects Of Hurricane Fault Architecture On Groundwater Flow In The Timpoweap Canyon Of Southwestern, Utah, Sarah J. Dutson
Effects Of Hurricane Fault Architecture On Groundwater Flow In The Timpoweap Canyon Of Southwestern, Utah, Sarah J. Dutson
Theses and Dissertations
Hydrogeologically important features of fault zones include undamaged country rock, the damage zone, and the core zone. Fault cores generally have low porosity and permeability, and often act as a barrier to groundwater flow. The damage zone, by contrast, consists of small faults and fracture networks, which can act as conduits. Timpoweap Canyon near Hurricane, Utah has superb exposures of the fault core and damage zone of the Hurricane Fault. Also within the canyon, springs discharge from the damage zone into the Virgin River, providing an ideal natural laboratory for the study of groundwater discharge from a fault zone. The …
Mass Transport Of Volatile Organic Compounds Between The Saturated And Vadose Zones, Monte S. Harner
Mass Transport Of Volatile Organic Compounds Between The Saturated And Vadose Zones, Monte S. Harner
Theses and Dissertations
Volatile organic compounds (VOCs) dissolved in the saturated zone are transported into the vadose zone primarily by gaseous phase diffusion. If the saturated zone is remediated, VOCs present in the vadose zone may become a secondary source of contamination for the groundwater. The amount of VOCs that remain in the vadose zone is dependent on site hydrology, soil properties, and the chemical properties of the contaminants. The purpose of this study was to determine what conditions caused VOC concentrations in the vadose zone to significantly recontaminate the saturated zone. A one-dimensional numerical model was developed to investigate the transport of …