Feeding Preference Studies of Adult \u3ci\u3eNezara Viridula\u3c/i\u3e (Hemiptera: Pentatomidae) Morphs from India and the United States

Nezara viridula (Linnaeus) morphs from India and the United States were studied in a laboratory comparison of feeding preferences for pods of soybeans, Glycine max, and green beans, Phaseolus vulgaris. Adults of a morph from the U.S. apparently selected pods at random, while three sympatric morphs from India generally preferred green bean pods

AN OPTIMAL CONTROL APPROACH TO WATER QUALITY TRADING: COST-EFFECTIVE POINT/NONPOINT MANAGEMENT IN A WATERSHED FRAMEWORK

This study reflects a growing interest in water quality trading involving both point and nonpoint sources in a watershed framework. An empirical spatial-temporal optimal control model is presented and solved to assess the scope and implications of point/nonpoint trading. Results indicate significant economic gains to broader based interpretations of trading rules.Resource /Energy Economics and Policy,

Examining Point-Nonpoint Trading Ratios for Acid Mine Drainage Remediation with a Spatial-Temporal Optimization Model

A trading ratio is required for water quality trading that involves nonpoint sources to compensate for the difficulty of determining nonpoint loadings, the stochastic characteristics of nonpoint loadings, and the uncertainty inherent in nonpoint source pollution control strategies. Compensating for risk and uncertainty is one of the primary justifications that a trading ratio greater than one is commonly considered. However, the appropriate specific value of a trading ratio remains unclear because of qualitative differences between point and nonpoint sources. This study addresses a growing concern with the analytical underpinnings of point/nonpoint trading ratios in water quality trading programs. This paper considers a basic spatial-temporal optimal control model assuming that the goal of the decision maker is to maximize ecological services from the watershed over a 10-year planning horizon given a predetermined budget each year to treat acid mine drainage problems. The level of pollution is assumed to be known but declining slightly over time as the acid mine drainage sources evolve. Resources are assumed to be spent on remediation projects that produce long term but declining treatment results. The primary goal of the model is to distribute the available resources over the basin by investing in restoration projects for targeted streams each year that will maximize the ecological return on this investment. The model reflects both the spatial reality of variations in flow, in pollution, in treatment, and in the ecological benefits produced and the intertemporal constraints of limited resources and the inability to move remediation programs once the initial investment is made. The resulting optimal temporal and spatial investment strategies are derived from solutions to a mixed integer programming problem obtained using the GAMS/CPLEX mixed integer programming package. The optimal results are then manipulated to evaluate trading ratios. A hypothetical acidity trading scenario is proposed in which a point source (a new coal mine operation subject to TMDL rules) uses credits generated through remediation projects at other sites from treatment of nonpoint sources within the same basin over the 10-year planning horizon. The trading ratio is the ratio of the expected amount of pollutant removed by treating the nonpoint source divided by the amount of additional pollution allowed from the new point source. Our results indcate that point/nonpoint trading ratios in proposed trading scenarios greater than one can be justified. For example, for a point/nonpoint trade between sources in adjacent stream segments, the appropriate trading ratio is 3.66 (or 3.66 to one). We note that current regulations give a lower bound for point/nonpoint trading ratio of 1:1. The upper bound for point/nonpoint trading ratio depends on technical aspects of the relative costs of treating the point source or treating nonpoint sources and reflects the limit of how much one is willing to pay for credits. A variety of factors determine trading ratios. First, to encourage trades with less uncertainty, trades in which the credit seller and buyer are in close proximity, and in which the credit seller is upstream, lower trading ratios are recommended. Second, trading ratios should be adjusted to favor trades that contribute to strategic restoration goals such as the improvement or maintenance of water quality in a particular basin. Reduced ratios provide incentives to promote the generation of credits in priority locations. Finally, trading ratios for same-pollutant trades should be lower than those for cross-pollutant trades. Three separate trading currencies would be used to account for same-pollutant acid mine drainage trades: pounds of iron, aluminum, and manganese. There would be little uncertainty in the outcome of a trade if the credit generator and buyer were affecting the same pollutant. In contrast, cross-pollutant trades that use a common currency such as ecological indices would be measured based on their ecological effect, which is one step removed from the actual changes in pollutant loads. The higher trading ratio required for cross-pollutant trades reflects this greater uncertainty. All potential trades considered in this study are interspatial trades; trades occur in the same basin; trades could be cross-pollutant trades within acid mine draiange and same-pollutant trades as well; and the credit buyer is the new coal mining operation; credit generators could be government agencies or nonprofit organization; and abandned mine lands and bond forfeiture sites can be sites where credits are generated.point-nonpoint water quality trading, trading ratio, acid mine drainage, spatial-temporal optimization, Environmental Economics and Policy,

TOTAL ECONOMIC VALUATION OF STREAM RESTORATION USING INTERNET AND MAIL SURVEYS

The economic value of restoring Deckers Creek in Monongalia and Preston Counties of West Virginia was determined from mail, internet and personal interview surveys. Multi-attribute, choice experiments were conducted and nested logit models were estimated to derive the economic values of full restoration for three attributes of this creek: aquatic life, swimming, and scenic quality. The relative economic values of attributes were: aquatic life > scenic quality ~ swimming. These economic values imply that respondents had the highest value for aquatic life when fully restoring Deckers Creek to a sustainable fishery rather than "put and take" fishery that can not sustain a fish population (defined as moderate restoration for aquatic life). The consumer surplus estimates for full restoration of all three attributes ranged between $12 and$16 per month per household. Potential stream users (anglers) had the largest consumer surplus gain from restoration while non-angler respondents had the lowest. When the consumer surplus estimates were aggregated up to the entire watershed population, the benefit from restoration of Deckers Creek was estimated to be about $1.9 million annually. This benefit does not account for any economic values from partial stream restoration. Based upon log likelihood tests of the nested logit models, two sub-samples of the survey population (the general population and stream users) were found to be from the same population. Thus, restoration choices by stream users may be representative of the watershed population, although the sample size of stream users was small in this study.Resource /Energy Economics and Policy,

Management of Multipurpose Heterogeneous Fishing Fleets Under Uncertainty

This paper describes an approach to modeling fisheries that can be useful in policy analysis when the population dynamics are not well known and the fleet is composed of a variety of multipurpose vessels. An empirical application of the methodology to the northern California Dungeness crab fishery is discussed. A multivariate time-series model provides the intertemporal (year-to-year) relationships for a simulation model describing both within season and year-to-year fleet behavior. Appropriate modifications of the simulation model parameters reflect alternative policy scenarios. The analysis of the simulation outcomes provide insight into fleet response to several management alternatives that have been considered for the crab fishery.Environmental Economics and Policy, Research Methods/ Statistical Methods, Resource /Energy Economics and Policy, Risk and Uncertainty,

NITROGEN MANAGEMENT IN SOUTHEASTERN MINNESOTA

Crop Production/Industries,

STREAM WATER QUALITY MANAGEMENT: A STOCHASTIC MIXED-INTEGER PROGRAMMING MODEL

Water quality management under the watershed approach of Total Maximum Daily Load (TMDL) programs requires that water quality standards be maintained throughout the year. The main purpose of this research was to develop a methodology that incorporates inter-temporal variations in stream conditions through statistical distributions of pollution loading variables. This was demonstrated through a cost minimization mixed-integer linear programming (MIP) model that maintains the spatial integrity of the watershed problem. Traditional approaches for addressing variability in stream conditions are unlikely to satisfy the assumptions on which these methodologies are founded or are inadequate in addressing the problem correctly when distributions are not normal. The MIP model solves for the location and the maximum capacity of treatment plants to be built throughout the watershed which will provide the optimal level of treatment throughout the year. The proposed methodology involves estimation of parameters of the distribution of pollution loading variables from simulated data and use of those parameters to re-generate a suitable number of random observations in the optimization process such that the new data preserve the same distribution parameters. The objective of the empirical model was to minimize costs for implementing pH TMDLs for a watershed by determining the level of treatment required to attain water quality standards under stochastic stream conditions. The output of the model was total minimum costs for treatment and selection of the spatial pattern of the least-cost technologies for treatment. To minimize costs, the model utilized a spatial network of streams in the watershed, which provides opportunities for cost-reduction through trading of pollution among sources and/or least-cost treatment. The results were used to estimate the costs attributable to inter-temporal variations and the costs of different settings for the margin of safety. The methodology was tested with water quality data for the Paint Creek watershed in West Virginia. The stochastic model included nine streams in the optimal solution. An estimate of inter-temporal variations in stream conditions was calculated by comparing total costs under the stochastic model and a deterministic version of the stochastic model estimated with mean values of the loading variables. It was observed that the deterministic model underestimates total treatment cost by about 45 percent relative to the 97th percentile stochastic model. Estimates of different margin of safety were calculated by comparing total costs for the 99.9th percentile treatment (instead of an idealistic absolute treatment) with that of the 95th to 99th percentile treatment. The differential costs represent the savings due to the knowledge of the statistical distribution of pollution and an explicit margin of safety. Results indicate that treatment costs are about 7 percent lower when the level of assurance is reduced from 99.9 to 99 percent and 21 percent lower when 95 percent assurance is selected. The application of the methodology, however, is not limited to the estimation of TMDL implementation costs. For example, it could be utilized to estimate costs of anti-degradation policies for water quality management and other watershed management issues.Resource /Energy Economics and Policy,

A spatial-temporal optimization approach to watershed management: AMD treatment in the Cheat River Watershed, WV: Working paper series--08-15

Most water management studies concentrate on the inter-temporal allocation problem or, more recently, spatial dynamics - but not both. While early spatial-temporal studies focused on the allocation of water quantity, this paper presents an approach to water quality analysis that incorporates both spatial and temporal dynamics in a watershed framework. The acid mine drainage (AMD) problem in the Cheat River watershed of West Virginia serves as a case study and provides an opportunity to test the modeling approach developed. The empirical models are written in General Algebraic Modeling System (GAMS) and solved using the CPLEX mixed integer programming package. The results suggest that available investments should be concentrated in heavily impaired stream segments. The model can be used to assess the economic implications of alternative watershed TMDL implementation or other management strategies