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- Constructed wetlands (2)
- Decision support systems (2)
- Hazardous waste site remediation--Decision making (2)
- Aquifers (1)
- Artificial substrates (Aquatic biology) (1)
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- Atmospheric diffusion (1)
- Biochemical oxygen demand--Mathematical models (1)
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- Environmentalism--United States (1)
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- Groundwater flow--Mathematical models (1)
- Groundwater flow--Simulation methods (1)
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- Groundwater--Pollution--Forecasting (1)
- Hazardous wastes--Management--Decision-making (1)
- Hydraulic measurements (1)
- Kriging (1)
- Plant canopies (1)
- Response surfaces (Statistics) (1)
- Runoff (1)
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- United States. Air Force--Officers--Attitudes (1)
Articles 1 - 12 of 12
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A Comparison Of Remediation Priorities Developed By The Defense Priority Model, The Relative Risk Evaluation Method, And A Quantitative Risk Assessment Approach, David M. Hunter
Theses and Dissertations
The Superfund, established by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, seriously underestimated both the number of severely contaminated sites and the associated cleanup cost. The magnitude of projected cleanup costs, coupled with shrinking federal budgets, necessitated the development and use of risk-based prioritization models among some federal agencies. Among these tools, the DOD prioritization models are meant to give priority to sites posing the greatest threat to human health. Their failure to properly rank sites could incorrectly shift the focus from those that pose substantial risk to sites of lesser risk. The DOD site ranking …
The Relationship Between Environmental Attitudes And Environmental Behaviors Among Air Force Members, Daniel T. Holt
The Relationship Between Environmental Attitudes And Environmental Behaviors Among Air Force Members, Daniel T. Holt
Theses and Dissertations
A questionnaire was distributed to nearly 2,000 randomly selected active duty Air Force members assigned to locations throughout the continental United States. The survey was designed to determine the extent to which Air Force members expressed support for environmental issues. In addition, the survey measured how frequently Air Force members engaged in specific behaviors that were deemed environmentally protective. Although the Air Force members expressed relatively strong support for environmental issues, they only occasionally engaged in activities that contribute to the preservation or protection of the environment. Correlation analysis revealed that the pro-environmental attitudes were positively linked to the environmentally …
Geostatistical Analysis Of Hydraulic Conductivity In Heterogeneous Aquifers, Craig S. Biondo
Geostatistical Analysis Of Hydraulic Conductivity In Heterogeneous Aquifers, Craig S. Biondo
Theses and Dissertations
Observations of the spatial variability of hydraulic conductivity of the heterogeneous alluvial aquifer at Columbus Air Force Base in Mississippi are analyzed using parametric geostatistical approaches. Field studies have revealed that the heterogeneity of the aquifer hydraulic conductivity field controls the movement and dispersion of groundwater solutes. Therefore, a means of quantifying spatial variability is essential for the application of flow and solute transport models to practical problems. Application of these models requires a large number of hydraulic conductivity measurements. Geostatistical analysis and kriging estimation procedures assist in providing these large numbers of values when sampling designs have provided sparse …
Evaluating The Feasibility Of Sequential Indicator Simulation In Reproducing Spatial Connectivity In A Heterogeneous Transmissivity Field, D. Duane Kenyon
Evaluating The Feasibility Of Sequential Indicator Simulation In Reproducing Spatial Connectivity In A Heterogeneous Transmissivity Field, D. Duane Kenyon
Theses and Dissertations
A Non-Parametric estimation technique was used to simulate realizations of a heterogeneous transmissivity field based upon sampled values from three different sampling scenarios. These realizations were compared to output from a parametric estimation technique with respect to truth as defined by an exhaustive data set of 6,000 transmissivity values. Estimated transmissivity fields were then used as input into a flow model from which fields of heads and specific discharges were obtained and compared. Given the financial limitations imposed upon the number and quality of samples reasonably available, Sequential Indicator Simulation, a non-parametric technique, was shown to be of considerable value …
The Effects Of Vegetative Canopies On Atmospheric Dispersion, John R. Lindell
The Effects Of Vegetative Canopies On Atmospheric Dispersion, John R. Lindell
Theses and Dissertations
This research was conducted to improve our understanding of the effects of vegetative canopy-induced turbulence on the dispersion of air pollution. The computer model most often used to calculate atmospheric dispersion is the Gaussian plume model, which requires some method to compute the downwind dispersions coefficients. These coefficients are a parameterization of the atmospheric stability or the level of turbulence in the atmosphere. The Environmental Protection Agency's recommended parameterization scheme is the Pasquill-Gifford method. By comparing the Pasquill-Gifford method to the Modified Mitchell method using sigma theta, the standard deviation of the horizontal wind fluctuations, the relative precision of each …
Decision Support Model To Optimize Site Characterization Activities Taken In Compliance With The Comprehensive Environmental Response Compensation And Liability Act, Daniel J. Clairmont
Decision Support Model To Optimize Site Characterization Activities Taken In Compliance With The Comprehensive Environmental Response Compensation And Liability Act, Daniel J. Clairmont
Theses and Dissertations
One of the most frequently cited reasons for the slow and costly progress of Superfund cleanups is the remedial investigation and feasibility study process (RI/FS). After each phase of the RI/FS process there are several possible alternatives that may be chosen. This research developed decision support models to help decision makers choose between the feasible alternatives at five different decision points during site characterization activities. The models make recommendations on how to deal with any particular chemical based on the risk posed by that chemical. The models assume that the value of characterizing the site further is a reduction in …
Comparison Of Gravel Substrate Vs Soil Substrate For The Construction Of An Experimental Fen, Carolyn S. Langley
Comparison Of Gravel Substrate Vs Soil Substrate For The Construction Of An Experimental Fen, Carolyn S. Langley
Theses and Dissertations
Under the Clean Water Act Section 404 of 1972 and 33 CFR 320-330 and 40 CFR 230 moderate the destruction of wetlands by the Air Force to make way for other uses. To obtain a permit for a design or construction project which affects a wetland, the Air Force must agree to create new wetlands, or replace lost wetland acreage through wetland creation or restoration. The Air Force is interested in building 'successful' wetlands as inexpensively as possible. It has been common practice to use hydric soil, which often had to be hauled in, as the substrate at the restored …
A System Dynamics Approach To Modelling The Degradation Of Biochemical Oxygen Demand In A Constructed Wetland Receiving Stormwater Runoff, Leslie A. Mudgett
A System Dynamics Approach To Modelling The Degradation Of Biochemical Oxygen Demand In A Constructed Wetland Receiving Stormwater Runoff, Leslie A. Mudgett
Theses and Dissertations
The objective of this research was to develop a tool to aid the Air Force Environmental Manager in the identification of the design parameters of a constructed wetland system that may be optimized to provide a desired biochemical oxygen demand (BOD) removal efficiency during the treatment of Air Force stormwater runoff. The objective is achieved through the development and use of a system dynamics model which simulates the hydrological functions of a constructed wetland as well as the processes within the wetland responsible for degradation of BOD. Based on literature review, the primary mechanism responsible for the degradation of BOD …
A Comparison Of Response Surface Methodology And A One-Factor-At-A-Time Approach As Calibration Techniques For The Bioplume-Ii Simulation Model Of Contaminant Biodegradation, Benjamin Shuman
Theses and Dissertations
This thesis compared Response Surface Methodology (RSM) to the one-factor-at-a-time approach for calibrating the Bioplume-II simulation model of contaminant biodegradation. The MADE-2 data set from Columbus Air Force Base, Mississippi was used. The one-factor-at-a-time approach reduced the root-mean-squared (RMS) error for the flow to 0.921225 feet in a total of 36 runs of Bioplume-II. The RSM approach reduced the error criterion to 0.918875 in a total of 47 runs. The one-factor-at-a-time approach was unable to reduce the error below 67.1831 parts per billion (ppb) after 21 runs. The RSM approach reduced the RMS error to 67.0327 ppb after 47 runs. …
A Point Model Of Aquifer Cleanup With A Distribution Of First-Order Rate Parameters, Jon E. Hodge
A Point Model Of Aquifer Cleanup With A Distribution Of First-Order Rate Parameters, Jon E. Hodge
Theses and Dissertations
Many try modeling groundwater contaminant transport to predict it. Is this possible with rate-limited processes, and under what conditions? On occasion, cleanups go slower than predicted (tailing) and hazardous concentrations reappear after cleanup is thought complete (rebound). Rate-limited transport is blamed by many. When immobile water is present, diffusion from varied sizes and shapes of immobile regions can cause varied rate limitations (due to varied diffusion path lengths). Although known, most modelers represent these varied rate-limiting processes with a single 'representative' rate-parameter. This can yield poor predictions for long-term experiments, and the parameter is generally time and pump-rate dependent. This …
A Decision Model For Environmental Assessment Of Process Waste Products, Kyle F. Byard
A Decision Model For Environmental Assessment Of Process Waste Products, Kyle F. Byard
Theses and Dissertations
Environmental managers must compare the potential impacts of waste products when deciding upon courses of action. The estimation and comparison of these impacts is a subjective process, and few methods of comprehensive, quantitative comparison of waste products currently exist. The intent of this study is to develop a decision methodology to evaluate the environmental impacts of waste products and to score them for comparison. The method will follow established system design principles and incorporate significant characteristics of the waste material. Scores derived to represent the environmental impacts of materials will then he analyzed employing statistical and probabilistic methods to assess …
Spatial Time-Series: Pollution Pattern Recognition Under Irregular Interventions, Samuel A. Wright
Spatial Time-Series: Pollution Pattern Recognition Under Irregular Interventions, Samuel A. Wright
Theses and Dissertations
The Fernald Environmental Restoration Management Corporation (FERMCO) has noted the introduction of arsenic contamination to groundwater around the area of the groundwater recovery system, which captures uranium contaminated groundwater. The introduction of arsenic occurs during high levels of pumping and is particularly sensitive to the western two of the five pumps. Auto-Regressive Moving Average (ARMA) and Spatial-Temporal ARMA (STARMA) empirical analyses are used to model the level of arsenic contamination found through time. The intervention of varied levels of pumping is modeled with a transfer function using analytic techniques to create a causal intervention transfer function input series to give …