Performance/Cost Estimates for Retrofitting Control Technologies

The U.S. EPA’s Air and Energy Engineering Research Laboratory is responsible for assessing control technology performance and costs under the National Acid Precipitation Assessment Program. A major part of this assessment involves developing site-specific estimates of the performance and costs of retrofitting SO₂ and NO_x control technologies for the top 200 SO₂- emitting (1980) coal-fired power plants in the 31-state eastern region. This effort includes detailed evaluation of a small number of plants (30 or less) representing a cross-section of the top 200 population. In cooperation with the states of Ohio and Kentucky (in conjunction with the U.S. EPA’s State Acid Rain Grant Program), efforts were undertaken to visit and conduct detailed evaluation of 12 coal-fired plants—five in Ohio, seven in Kentucky and the Tennessee Valley Authority System. A variety of commercial and advanced SO₂ and NO_x control technologies—including precombustion, combustion (in-furnace), and postcombustion (flue gas cleanup) technologies—were applied to each plant through conceptual designs. Retrofit factors (applied to the capital cost of a new pollution control system), cost “adders” (e.g., movement of existing equipment), and costs were developed for applying the control technologies to the boilers of each plant. Results of these and subsequent efforts will be valuable in evaluations of acid deposition control strategies by federal and state agencies and by electric utilities.     

Wheat yield functions for analysis of land-use change in China

CERES-Wheat, a dynamic process crop growth model, is specified and validated for eight sites in the major wheat-growing regions of China. Crop model results are then used to test the Mitscherlich-Baule and the quadratic functional forms for yield response to nitrogen fertilizer, irrigation water, temperature, and precipitation. The resulting functions are designed to be used in a linked biophysical-economic model of land-use and land-cover change in China. While both functions predict yield responses adequately, the Mitscherlich-Baule function is preferable to the quadratic function because its parameters are biologically and physically realistic. Variables explaining a significant proportion of simulated yield variance are nitrogen, irrigation water, and precipitation; temperature was a less significant component of yield variation within the range of observed year-to-year variability at the study sites. Crop model simulations with a generic soil with median characteristics of the eight sites compared to simulations with site-specific soils showed that agricultural soils in China have similar and, in general, low-to-moderate water-holding capacities and organic matter contents. The validated crop model is useful for simulating the range of conditions under which wheat is grown in China, and provides the means to estimate production functions when experimental field data are not available.     

Local attitudes on protected areas: Evidence from three Natura 2000 wetland sites in Greece

Environmental policies aimed at the conservation of protected areas are significantly influenced by social factors revealing the importance of investigating local knowledge and perceptions during their planning and implementation. The present article aims to explore perceptions and awareness of citizens in three protected areas of Greece: The National Park of Eastern Macedonia and Thrace, the Wetland of Kalloni, and Lake Tavropou. The survey explores perceptions of individuals on environmental issues and alternative management scenarios referring to management actors, funding sources, and management schemes for the conservation of biodiversity. Differences between the three research areas are also explored. According to the results of the study, citizens are in general supportive of protected areas and present relatively high levels of knowledge of environmental issues. However, environmental awareness is not accompanied by active participation for the resolution of environmental problems. By exploring differences between the three research areas, it is revealed that the provision of information significantly influences individuals’ perceptions on relevant issues. Also, a significant finding of the study is that citizens are supportive of some forms of participatory management. It is essential, to encourage public participation and deliberation in order to promote their sustainable management.     

Variability in the spatial association patterns of sponge assemblages in response to environmental heterogeneity

Previous work on tropical sponge assemblages has provided strong evidence that sponges coexist on coral reefs through a diversity of positive and negative associations; however, the majority of this work has focused on Caribbean coral reefs. Here, we investigate the intra-phyletic spatial associations between the 20 most abundant sponge species at two sites experiencing different environmental regimes in the Wakatobi National Marine Park, Indonesia. We used a Monte Carlo simulation approach to compare the number of spatial associations between each species pair to that expected if species distribution patterns were non-associative (i.e. random). We found that sponges were predominately randomly distributed at the high coral cover site, whereas most sponges were negatively associated with other sponges at the sedimented, low coral cover site. We also found differences between distribution patterns for specific species at the two sites; a number of species that showed a random distribution pattern at the high coral cover site had negative association patterns at the low coral cover site. Our research supports recent ecological studies suggesting that interactions between species are unlikely to be homogenously distributed, as we found that some sponge species interactions differed depending on the environmental regimes in which they were found; this suggests that species interactions may be spatially variable. Finally, our results contrast with studies from elsewhere, as the sponge assemblages at these two sites in the Wakatobi appear to be dominated by negative associations and random distribution patterns rather than widespread competition.     

A Review of the Air Pollution Research Program of the Smoke and Fumes Committee of the American Petroleum Institute

Canada’s new Green Plan charts a course for dealing with environmental issues that will require an unflinching commitment to changes in thought, decision-making and action by all sectors of Canadian society. The five-year, $3-billion Plan lists 120 specific initiatives in eight areas of activity. It will enlist the participation of some 40 federal departments and agencies, alone, cooperatively or in creative partnerships with industry, the academic and scientific community, and citizens’ groups.     

Surrogate Measures for Providing High Frequency Estimates of Total Suspended Solids and Total Phosphorus Concentrations1

Spackman Jones, Amber, David K. Stevens, Jeffery S. Horsburgh, and Nancy O. Mesner, 2010. Surrogate Measures for Providing High Frequency Estimates of Total Suspended Solids and Total Phosphorus Concentrations. Journal of the American Water Resources Association (JAWRA) 1‐15. DOI: 10.1111/j.1752‐1688.2010.00505.x Abstract: Surrogate measures like turbidity, which can be observed with high frequency in situ, have potential for generating high frequency estimates of total suspended solids (TSS) and total phosphorus (TP) concentrations. In the semiarid, snowmelt‐driven, and irrigation‐regulated Little Bear River watershed of northern Utah, high frequency in situ water quality measurements were recorded in conjunction with periodic chemistry sampling. Site‐specific relationships were developed using turbidity as a surrogate for TP and TSS at two monitoring locations. Methods are presented for employing censored data and for investigating categorical explanatory variables (e.g., hydrologic conditions). Turbidity was a significant explanatory variable for TP and TSS at both sites, which differ in hydrologic and water quality characteristics. The relationship between turbidity and TP was stronger at the upper watershed site where TP is predominantly particulate. At both sites, the relationships between turbidity and TP varied between spring snowmelt and base flow conditions while the relationships between TSS and turbidity were consistent across hydrological conditions. This approach enables the calculation of high frequency time series of TP and TSS concentrations previously unavailable using traditional monitoring approaches. These methods have broad application for situations that require accurate characterization of fluxes of these constituents over a range of hydrologic conditions.