VTechWorks Repository :: Browsing by Author "Stephenson, Stephen Kurt"

Browsing by Author "Stephenson, Stephen Kurt"

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Achieving Water Quality Goals in the Chesapeake Bay: A Comprehensive Evaluation of System Response
Scientific & Technical Advisory Committee (EPA, Chesapeake Bay Program, Scientific and Technical Advisory Committee, 2023-05-04)
Adoption of Integrated Pest Management Technologies: A Case Study of Potato Farmers in Carchi, Ecuador
Mauceri, Maria (Virginia Tech, 2004-12-16)
Potato farmers in Ecuador rely on chemical inputs to manage pests and optimize yields. IPM techniques are recommended to lower production costs, reduce exposure to pesticides, and improve the long-term sustainability of the agriculture system. We conducted a survey of 109 potato farmers in Carchi, Ecuador that included 30 Farmer Field School (FFS) participants, 28 farmers who had been exposed to FFS-participants, and 51 randomly selected farmers. Using an ordered probit model, the data were analyzed to identify determinants and constraints of adoption. Access to information through FFS was the main determinant of adoption of IPM, followed by field days, pamphlets, and exposure to FFS-participants. The study looked at the relative cost-effectiveness of information dissemination methods and found that field days and pamphlets have strong impacts on adoption considering their low cost of implementation. The only significant household variable was household size, where larger households adopted less IPM. Per capita land holdings were not significant in the model. There is evidence of farmer-to-farmer diffusion from FFS to non-FFS farmers. Further research is necessary to evaluate the nature and quality of information transfer between farmers. The study was limited by the small sample size and non-random selection of farmer respondents.
Analysis of In-Lieu Fee Programs in providing Wetland and Stream Compensatory Mitigation
Tutko, Benjamin Thomas (Virginia Tech, 2017-10-16)
The nation's Section 404 permitting program, of the Clean Water Act (CWA), represents one of the longest regulatory histories of designing and implementing credit trading programs to satisfy regulatory requirements. The role and the function of in-lieu fee (ILF) programs in supporting this regulatory structure have undergone a substantial change. For the first time in the history of the Sec. 404 program, 33 CFR Part 332 and 40 CFR Part 230, Subpart J (the "2008 mitigation rule" or "rule"), prioritizes the use of off-site mitigation over on-site-mitigation. Additionally, the rule prioritizes advanced, third-party mitigation; especially as achieved through mitigation banks; over any off-site compensatory mitigation provided by ILF programs (33 CFR 332.3(b)(1)). This new regulatory environment favors the use of commercial mitigation bank credits while acknowledging that the limited permittee demand of off-site mitigation credits, in particular areas, justifies the continuing need for ILF programs (Corps and EPA 2008, p.19606,19611). This research examines how regulatory officials use ILF programs under the 2008 mitigation rule, and, it determines the extent to which ILF programs are capable of fulfilling the role envisioned for them under the 2008 mitigation rule. Simulation results indicate that commercial mitigation banks cannot meet risk adjusted returns under limited credit demand conditions. ILF programs offer some additional financial capacity to fill the void in commercial bank coverage; but, this potential is limited in low demand conditions. Furthermore, empirical case studies of a Virginia and Georgia provide evidence that regulatory officials rely on ILF programs to provide off-site compensatory mitigation almost exclusively in the absence of private credit supply, as intended in the 2008 rule. Evidence in Georgia and Virginia also indicate that, in some situations, ILF programs face difficulties in providing mitigation under the constraints of limited demand and more stringent regulatory requirements.
Analyzing Cost Implications of Water Quality Trading Provisions: Lessons from the Virginia Nutrient Credit Exchange Act
Aultman, Stephen (Virginia Tech, 2007-07-26)
The purpose of this study was to analyze the cost implications of various provisions of the Virginia Nutrient Credit Exchange Act. The first objective was to estimate the cost implications of point source trading provisions of the Act. An integer programming cost minimization model was constructed to estimate the cost of achieving four point source trading policy scenarios. The model estimated the annual cost of meeting two different nutrient cap levels, each with and without a limits-of-technology concentration standard requirement for new and expanding point sources. The limits-of-technology concentration standard requirement was found to significantly affect cost while providing little apparent benefit to water quality. The second objective was to develop a screening procedure for municipalities to estimate the cost of generating waste load allocation from nonpoint source offsets under their jurisdictional control. A spreadsheet based cost screening procedure was developed for municipalities to estimate the cost of implementing of nitrogen offsets from stormwater practices, septic retirement, and land conversion. One of the important findings from developing the screening procedure is that the cost of generating WLA from non-point sources under the control of local governments was much higher than the cost of removing nitrogen at wastewater treatment plants.
Artificial sinks to treat legacy nutrients in agricultural landscapes
Bock, Emily; Stephenson, Stephen Kurt; Easton, Zachary M. (2019-06-05)
Legacy nutrients introduce a critical time lag between changes in nutrient application or implementation of best management practices (BMPs) and observable reductions in loads delivered to downstream waters. Nitrogen and phosphorus leached through soils into groundwater may take decades to eventually be discharged to surface waters and, consequently, often prevent the attainment of water quality improvement goals. For example, the National Resource Council has cautioned that in the Chesapeake Bay watershed legacy nutrients, particularly nitrogen (N), could delay achievement of nutrient load reductions needed to meet Total Maximum Daily Load (TMDL) requirements.. Groundwater discharge transporting legacy N has been identified specifically as a significant nutrient source to the Bay. Unfortunately, most existing BMPs cannot remediate these nutrient reservoirs and the Chesapeake Bay Program has not active policy to address legacy nutrients; better management options are needed...
BMP Cost and Nutrient Management Effectiveness on Typical Beef and Beef-Poultry Farms in Shenandoah County, Virginia
Dickhans, Megan F. (Virginia Tech, 2010-05-04)
This study analyzes the change in whole-farm net revenues and nutrient reduction from the implementation of five best management practices (BMPs) on a typical beef and beef-poultry farm in Shenandoah County. Whole-farm net revenues, resource allocation, nutrient loss reductions, and the cost efficiency of reducing nutrient losses were analyzed to assess which BMPs are the most cost efficient to implement, assuming the baseline scenarios have no voluntarily applied BMPs. The effects of stacking additional BMPs, in combinations of two or more, were also assessed. No-till cropping, winter wheat cover crop, herbaceous riparian buffer, fencing, and P-based NMP were the BMPs that were analyzed. Incentive payments from state and federal governments were incorporated into the cost of BMP adoption. A brief analysis of a farmer's time value of money, with respect to incentive payments, was also conducted. Results indicated that no-till crop management was the most cost efficient BMP, and was the only BMP to increase net revenues for both farm models. Fencing and P-based NMP were the least cost efficient for the beef farm. For the beef-poultry farm, fencing was the least cost efficient. The implications of this study are that farmers that choose to adopt BMP should evaluate both their interests in maintaining (or increasing) farm net revenues along with their interest in improving water quality through the reduction of nutrient losses. There is potential for implementing multiple BMPs, while increasing net revenues from a farm's baseline scenario. For farmers and policy makers, no-till cropping can be a profitable and therefore cost efficient BMP to implement. Incentive payments are intended to encourage the adoption of BMPs by subsidizing a portion of the start-up costs. Policy makers should attempt to make cost-share payments reflect nutrient reduction goals. This can be done by analyzing both the compliance cost to farmers and the nutrient reduction effectiveness of BMPs.
Challenges and Opportunities for Denitrifying Bioreactors in the Mid-Atlantic
Bock, Emily (Virginia Tech, 2018-01-18)
Sustaining the global population depends upon modern agricultural practices reliant on large inputs of nitrogen (N) fertilizer, but export of excess N from agroecosystems has negative environmental consequences, such as accelerated eutrophication and associated water quality degradation. The challenges posed by diffuse and widespread nutrient pollution in agricultural drainage waters necessitate cost-effective, adaptable, and reliable solutions. In this context, enhanced denitrification approaches developed over the last several decades have produced denitrifying bioreactors that harness the ability of ubiquitous soil microorganisms to convert bioavailable N into inert N gas, thereby removing bioavailable N from an ecosystem. Denitrifying bioreactors are edge-of-field structures that consist of organic carbon substrate and support the activity of denitrifying soil bacteria that remove N from intercepted nutrient-enriched drainage waters. The potential to improve bioreactor performance and expand their application beyond the Midwest to the agriculturally significant Mid-Atlantic region was investigated with a three-pronged approach: 1) a pilot study investigating controls on N removal, 2) a laboratory study investigating controls on emission of greenhouse gases nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), and 3) a field study of one of the first denitrifying bioreactors implemented in the Atlantic Coastal Plain. The pilot and laboratory studies tested the effect of amending woodchip bioreactors with biochar, an organic carbon pyrolysis product demonstrated to enhance microbial activity. The pilot-scale study provides evidence that either hardwood- of softwood-feedstock biochar may increase N removal in woodchip bioreactors, particularly under higher N loading. The results from the laboratory experiment suggest the particular pine-feedstock biochar tested may induce greater greenhouse gas emissions, particularly of the intermediate product of denitrification and potent GHG nitrous oxide. The field study evaluated performance of a biochar-amended woodchip bioreactor installed on a working farm. Two years of monitoring data demonstrated that the bioreactor successfully removed N from drainage waters, but at relatively low rates constrained by low N loading that occurred in the absence of fertilizer application during continuous soy cropping at the site (10.0 kg NO3--N ha-1 yr-1 or 4.86 g NO3- -N m-3 d-1 on the basis of bed volume reached the bioreactor.) Removal rates averaged 0.41 g m-3 d-1 (8.6% removal efficiency), significantly lower than average rates in systems receiving greater N loading in the Midwest, and more similar to installations in the Maryland Coastal Plain. Greenhouse gas fluxes were within the range reported for other bioreactors, and of the N removed an average of only 0.16% was emitted from the bed surface as N2O. This case study provides useful measurements of bioreactor operation under low N loading that informs the boundaries of bioreactor utility, and may have particular regional relevance. The pilot and field studies suggest that wood-based biochars may enhance N removal and may not produce problematic quantities of greenhouse gases, respectively. However, the laboratory study raises the need for caution when considering the costs and benefits amending woodchip bioreactors with biochar and accounting for the effect on greenhouse gas emissions in this calculation, because the tested pine biochar significantly increased these emissions.
Comparisons of the Educational Outcomes from Distance Delivered versus Traditional Classroom Instruction in Principles of Microeconomics
Crouse, Tricia Lynn (Virginia Tech, 2002-10-04)
Recent advancements in the speed and availability of the Internet have catapulted distance education into the forefront of possible economic education alternatives. Distance learning courses are taught exclusively over the Internet. Economics distance courses provide alternatives for economics students to traditional classroom instruction, and also invite new students to the discipline who may not have otherwise enrolled. An increase in the number of distance courses in the economics field has sparked a debate over the ability of distance courses to provide equivalent educational outcomes as traditional in-class courses. This study evaluates educational outcomes from a traditional section and two distance sections of introductory agricultural microeconomics courses, Economics of the Food and Fiber System (AAEC 1005), taught at Virginia Tech. The study compares student learning, attitudes and interests in economics, and perceptions of instructor effectiveness between traditionally taught students and those taught through distance education. Average exam scores, and common exam questions given to students in both course types, are the measures of student learning used in this study. Attitudes and interest are measured by student survey, and perceptions of instructor effectiveness are measured by student course evaluations. A variety of statistical tests are conducted comparing distance and traditional students in order to determine the influence of delivery method on educational outcomes. Results indicate that traditional students generally obtain higher grades on tests, and have a higher opinion of course instruction than distance students, suggesting that distance education is not an equivalent educational alternative to traditional classroom instruction.
Computational Tools for Improved Analysis and Assessment of Groundwater Remediation Sites
Joseph, Joshua Allen Jr. (Virginia Tech, 2008-04-24)
Remediation of contaminated groundwater remains a high-priority national goal in the United States. Water is essential to life, and new sources of water are needed for an expanding population. Groundwater remediation remains a significant technical challenge despite decades of research into this field. New approaches are needed to address the most severely-polluted aquifers, and cost-effective solutions are required to meet remediation objectives that protect human health and the environment. Source reduction combined with Monitored Natural Attenuation (MNA) is a remediation strategy whereby the source of contamination is aggressively treated or removed and the residual groundwater plume depletes due to natural processes in the subsurface. The USEPA requires long-term performance monitoring of groundwater at MNA sites over the remediation timeframe, which often takes decades to complete. Presently, computational tools are lacking to adequately integrate source remediation with economic models. Furthermore, no framework has been developed to highlight the tradeoff between the degree of remediation versus the level of benefit within a cost structure. Using the Natural Attenuation Software (NAS) package developed at Virginia Tech, a set of formulae have been developed for calculating the TOR for petroleum-contaminated aquifers (specifically tracking benzene and MTBE) through statistical techniques. With the knowledge of source area residual saturation, groundwater velocity, and contaminant plume source length, the time to remediate a site contaminated with either benzene or MTBE can be determined across a range of regulatory maximum contaminant levels. After developing formulae for TOR, an integrated and interactive decision tool for framing the decision analysis component of the remediation problem was developed. While MNA can be a stand-alone groundwater remediation technology, significant benefits may be realized by layering a more traditional source zone remedial technique with MNA. Excavation and soil vapor extraction when applied to the front end of a remedial action plan can decrease the amount of time to remediation and while generally more expensive than an MNA-only approach, may accrue long-term economic advantages that would otherwise be foregone. The value of these research components can be realized within the engineering and science communities, as well as through government, business and industry, and communities where groundwater contamination and remediation are of issue. Together, these tools constitute the Sâ ªEâ ªEâ ªPâ ªAGE paradigm, founded upon the concept of sound science for an environmental engineering, effectual economics, and public policy agenda. The TOR formulation simplifies the inputs necessary to determine the number of years that an MNA strategy will require before project closure and thus reduces the specialized skills and training required to perform a numerical analysis that for one set of conditions could require many hours of simulation time. The economic decision tool, that utilizes a life cycle model to evaluate a set of feasible alternatives, highlights the tradeoffs between time and economics can be realized over the lifetime of the remedial project.
Confronting our Agricultural Nonpoint Source Control Policy Problem
Stephenson, Stephen Kurt; Shabman, Leonard; Shortle, James; Easton, Zachary M. (Wiley, 2022-06-07)
Federal and state agricultural and environmental agencies have spent enormous sums since the 1990s to reduce nonpoint source (NPS) water pollution from agriculture. Yet, water quality problems are pervasive, and agriculture is a major cause. The lack of progress is often attributed to insufficient funding for pollution control practices relative to the scale of the problem. However, we attribute the lack of progress to shortcomings in agricultural NPS pollution control policy. We illustrate our argument after considering nearly four decades of federal, state, and local efforts to reduce agricultural NPS pollution to the Chesapeake Bay. Additional funding for current programs, absent fundamental program reform, is unlikely to produce reductions from agriculture needed to achieve desired water quality outcomes.
Consideration of BMP Performance Uncertainty in Chesapeake Bay Program Implementation: Workshop Report
Benham, Brian L.; Easton, Zachary M.; Hanson, Jeremy; Hershner, Carl; Julius, Susan; Stephenson, Stephen Kurt; Hinrich, Elaine (Scientific and Technical Advisory Committee, Chesapeake Bay Program, 2018-02-21)
Achieving Chesapeake Bay Program (CBP) nutrient and sediment reduction goals will require securing reductions largely from agricultural and urban nonpoint sources. While state and local governments rely largely on best management practices (BMPs) to achieve these goals, uncertainty surrounds the pollutant control effectiveness of these investments. Currently, the variation of BMP performance is not well documented or characterized in the CBP. Furthermore, knowledge gaps exist surrounding the sources and extent of the variation surrounding BMP performance. The purpose of this workshop was to make recommendations for improving the documentation and characterization of BMP performance uncertainty and to suggest how more detailed information on BMP uncertainty could be used to inform management decisions. Through this report, the workshop participants make several recommendations for characterizing uncertainty during the process of generating BMP effectiveness estimates (BMP Expert Panel Process). These include recommendations that the Chesapeake Bay Program partnership take measures to:

Systematically document and represent uncertainties throughout the BMP treatment process;

Produce information about the distribution of removal effectiveness of each BMP;

Develop a method for simply and effectively communicating the degree and type of uncertainty across all approved BMPs; and

Provide additional guidance for how to most effectively solicit “best professional judgment” as part of the expert panel process, including best practices for structured literature syntheses, identifying and avoiding potentially inappropriate heuristics (shortcuts) and biases when obtaining expert opinion, and expert elicitation.
Cost-Effective Methods for Reducing Sediment Loads in the Lick Run Watershed
Thompson, Theresa M.; Sample, David J.; Stephenson, Stephen Kurt; Towsif Khan, Sami; Macdonald, Kiara (2024-05-15)
December 2006 Report Of The Academic Advisory Committee To Virginia Department Of Environmental Quality: Freshwater Nutrient Criteria For Rivers And Streams
Zipper, Carl E.; Yagow, Eugene R.; Walker, Jane L.; Smith, Eric P.; Shabman, Leonard A.; Smock, Leonard A.; Hershner, Carl H.; Younos, Tamim M.; Benfield, Ernest F.; Bukaveckas, Paul A.; Garman, Greg C.; Kator, Howard I.; Lung, Wu-Seng; Stephenson, Stephen Kurt (Virginia Water Resources Research Center, 2007-01-10)
This report reviews activities conducted by the Academic Advisory Committee to the Virginia Department of Environmental Quality (DEQ) between July and December 2006. Activities were conducted for the purpose of developing recommendations for DEQ regarding nutrient criteria for freshwater rivers and streams.
December 2006 Report of the Academic Advisory Committee to Virginia Department of Environmental Quality: Freshwater Nutrient Criteria for Rivers and Streams
Zipper, Carl E.; Yagow, Eugene R.; Walker, Jane L.; Smith, Eric P.; Shabman, Leonard A.; Smock, Leonard A.; Hershner, Carl H.; Younos, Tamim M.; Benfield, Ernest F.; Bukaveckas, Paul A.; Garman, Greg C.; Kator, Howard I.; Lung, Wu-Seng; Stephenson, Stephen Kurt (Virginia Water Resources Research Center, 2007-01-10)
This report reviews activities conducted by the Academic Advisory Committee to the Virginia Department of Environmental Quality (DEQ) between July and December 2006. Activities were conducted for the purpose of developing recommendations for DEQ regarding nutrient criteria for freshwater rivers and streams.
Developing a Stormwater Pond Filter to Capture Phosphorus and Other Pollutants
Houston, Stephanie Chung-Pei-Hua (Virginia Tech, 2018-06-11)
Excess nutrients, particularly phosphorus (P), significantly contribute to anthropogenic eutrophication, which negatively impacts ecosystems, human health, and the economy. Traditional Best Management Practices (BMPs) such as wet retention ponds prevent eutrophication by acting as a sink for nutrients, but can become a source of pollutants if not properly monitored and maintained. A proposed solution is a standalone, multi-stage filter system that can attach to BMPs with standing water for targeted removal of excess nutrients and with the potential to recycle the filter media. The studies in this dissertation seek to address the feasibility of this solution through the following tasks: 1.) develop a tool that can identify ponds and locations within ponds with high total phosphorus (TP) concentrations, 2.) evaluate filter media that can remove P and can be recycled along with captured P, and 3.) develop a filter system that can remove pollutants in separate stages for the option to recycle certain pollutants. The studies focused primarily on P because the nutrient has the potential to be recycled if captured within the filter. Models developed in the first task showed that TP concentrations in the water were correlated with the pond outlet, pH of the water, and iron concentrations. TP concentrations in the sediment were correlated with the pond's length-to-width ratio and the concentration of aluminum and copper. For the second task, a batch experiment and measurements of physicochemical properties were conducted on four biochars (corn stover pyrolized at 400°C , corn stover pyrolized at 600°C, mixed hardwood, and rice husk). Results indicated that mixed hardwood biochar could sorb dissolved phosphorus (DP) above a solution concentration of 2.9 mg P/L. The properties that could allow this biochar to sorb DP were a smaller negative surface charge, high surface area, smaller concentration of elemental P, and more water-extractable cations. A laboratory-scale test of a three-stage filter system was performed as part of the third task. The filter effectively separated nitrogen and P in different stages, but did not separate lead from P. Median water quality parameters (pH, conductivity, temperature, turbidity, dissolved oxygen, carbon, iron) met U.S. EPA recommended limits, but some parameters violated the recommended limits at a few time points. These studies demonstrate that excessive pollutant concentrations exist in current BMPs, which can benefit from a filter system. The filter system has the potential to collect pollutants separately provided that the correct media mix and configuration is identified such that P can be more completely isolated and water quality parameters are met.
An Economic Evaluation of the Nutrient Assimilation Potential for Commercial Oyster Aquaculture in the Chesapeake Bay
Miller, Alexander Louis (Virginia Tech, 2009-01-08)
The Chesapeake Bay states continue to struggle to achieve the water quality goals set out in the Chesapeake Bay Agreement. While policy efforts to combat eutrophication tend to focus on reducing nutrient loads at point and nonpoint sources, waters of the Bay can be improved through an increase in the assimilative capacity of the ecosystem, which would remove nutrients (called nutrient assimilation services) from ambient waters. The filtering capacity of the native oyster, C.virginica, is a widely recognized means to enhance water quality. With an increase in the number of oysters in the Bay, and no decrease in wild stocks, oyster aquaculture has the potential to also increase the nutrient assimilation capacity of the ambient environment. Yet the expansion of commercial aquaculture in the Bay has been limited by financial constraints. Increased water quality services might be forthcoming if oyster aquaculturists received financial compensation for the nutrient removal services they provide. Based on previous research, this study develops a procedure for estimating annual nutrient removal from a given size oyster aquaculture facility. Next, a firm level bio-economic simulation model was constructed to estimate the amount of compensation needed by a commercial oyster aquaculture firm to make a new investment in oyster aquaculture. The amount of compensation needed is interpreted as the cost of providing nutrient removal by oyster aquaculture. Results indicate that under many circumstances, nutrient removal services can be provided by oyster aquaculture facilities at a per unit cost comparable with some non-point and point source nutrient removal technologies. Finally, a select number of funding resources were identified as potential outlets for creating payments and demand for nutrient assimilation services.
The Economic Feasibility of Partially Replacing Coal with Poultry Litter during the Production fo Energy in Virginia's Chesapeake Bay Watershed
Rios, Arturo Daniel (Virginia Tech, 2003-01-28)
Nutrient runoff from excess land application of poultry litter in the Chesapeake Bay Watershed has caused damage to the Chesapeake Bay and lead to the need for alternative poultry litter disposal methods. This study provided an economic feasibility analysis of the use of poultry litter as a partial replacement of coal at an electrical generating unit in Virginia's Chesapeake Bay Watershed. Previous research on the feasibility of converting litter to energy failed to include uncertainty in benefit-cost variables, therefore, this study used risk analysis to incorporate variable uncertainty. Project net worth in previous studies was measured under a public investment scenario with risk neutral preferences but did not take into account risk averse preferences common in private investment. This paper compared benefits under both public risk neutral and private risk averse investor preferences. NPV results showed the proposed project to be feasible but sensitive to the acquisition cost of poultry litter, the unit ash value of litter, and future coal price projections. The maximum level of risk aversion required for feasibility increased when expected returns were measured on an investment scale compared to an annual income scale. Poultry litter combustion produced lower levels of NOx and SO₂ emissions compared to coal, therefore, emission allowance trading through the EPA market based trading programs generated additional benefits to the model and increased the maximum level of risk aversion permitted for feasibility. Results suggested the potential to dispose of 110 thousand tons of poultry litter per year from the Chesapeake Bay Watershed without violating EPA emission standards.
An Economic Impact Assessment of the Green Industry of Virginia
Coppedge, Emily Jean (Virginia Tech, 2004-06-28)
An analysis of the green industry of Virginia was completed in the year 2002 using a mail survey sent to industry participants. The survey was conducted by the Virginia Agricultural Statistics Service (VASS). This data was used to run an economic impact analysis of the industry using IMPLAN Professional software. Additionally, the software was used to determine the approximate affects of drought and water restrictions on the green industry. VASS received a total of 1,146 surveys for a response rate of approximately 27%. Of these responses, 42 surveys indicated that they plan to have future green industry sales but were not presently involved in the business. Another 525 responses claimed to be no longer actively involved in the industry. Therefore, the actual response rate was much closer to 15%. This necessitated the use of numerous alternative data sources to create a more complete model representation of the green industry as a whole. Two separate model scenarios were created, the first using purely survey response data, the second including data from additional sources and factoring out for possible double-counting errors. Direct employment generated from the industry was predicted to be between 29 and 36 thousand jobs, depending on which model scenario is consulted. The total economic impacts predicted from the different models are $2.03 billion and $2.41 billion, respectively. The analysis of the affects of drought and water restrictions predicted a decrease in overall impacts by 33% and 23%, respectively.
An Economic Investigation of the Economic Impacts of Coastal Plain Aquifer Depletion and Actions That May Be Needed to Maintain Longterm Availability and Productivity
Stephenson, Stephen Kurt; Abt Associates (Virginia Department Of Environmental Quality, 2014)
The Virginia Department of Environmental Quality (DEQ) is concerned about declining aquifer levels in the Coastal Plain and the possibility that current and likely future withdrawals from the aquifers cannot be sustained. Because of this concern, DEQ is exploring possible new actions that would reduce groundwater use in the region. While lower overall groundwater withdrawals are desired, DEQ has not yet proposed specific actions to address depletion in the coastal aquifers. Before proceeding with new actions, DEQ is interested in understanding the potential economic impacts of reduced groundwater availability and the potential economic impacts of a range of management alternatives. This report summarizes an investigation into these potential economic impacts. The introductory section provides context for the rest of the report. Section 1.1 describes existing state policies and regulations, as well as DEQ’s groundwater management goal and regulatory criteria. Section 1.2 provides an overview of the problem while Section 1.3 describes the aquifer conditions and groundwater use trends that provide the motivation and context for this study. Finally, section 1.4 provides an overview of the remainder of the report.
Economic Significance of Selective Export Promotion on Poverty Reduction and Inter-Industry Growth of Ethiopia
Chala, Zelalem Teklu (Virginia Tech, 2010-06-25)
The purpose of this thesis was to assess the economic implications of an export promotion policy on poverty reduction and inter-industry growth of Ethiopia. The study was conducted in four steps. The first and the second steps involved simulation scenarios. Scenario 1 simulated the change in the incidence of poverty when FDI capital was selectively introduced into non-coffee export agriculture. Scenario 2 simulated a situation in which the coffee industry received the same policy treatment as other export agriculture in accessing FDI capital. Step three analyzed inter-industry growth under the two scenarios. In the fourth step, sensitivity analysis was conducted to assess the possible outcomes of Scenario 1 and 2 under fluctuations in world coffee prices and changes in substitution parameters. A micro-simulated CGE model was constructed to determine optimum production, income and consumption. A Beta frequency distribution function and FGT poverty measures were used to examine the changes in three household groups' income distribution and prevalence of poverty. For these analyses, the National Accounting Matrix and the Household Income and Expenditure Sample Survey data set were used. At the macro level, growth in GDP due to expansion of export agriculture was significant. But at a micro level, the magnitude and dimension of economic changes were different with respect to each policy alternative. In the selective export promotion, for instance, only rural households were able to achieve statistically significant income changes. More particularly, about 10 percent of rural households were drawn out of poverty while only 1.7 and 0.5 percent of small and large urban households overcame poverty. When export promotion was assumed to be implemented across the board of all agricultural activities, the welfare gains were extended beyond rural household groups. In this policy alternative, statistically significant mean income changes were observed for both rural and urban household members. Specifically, about 12 percent of rural, 9 percent of small urban and 5 percent of large urban households were able to escape poverty. These achievements were attributed to higher intensification of coffee production and better linkages with other industries to efficiently allocate factors of production where they provided higher rates of return. The increase in income and consumption of millions of coffee dependent households has also stimulated more agricultural and some non-agricultural productions. Simulation results were observed to deteriorate when export promotion was evaluated under world coffee price fluctuation. The negative effect of a price shock, however, was observed to be minimized under alternative an export promotion approach.

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