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941.
The precautionary principle is regularly cited in cases that involve development in eco-sensitive locations. We investigated whether the precautionary principle provides the basis for a coherent framework to prevent environmental harm, and does it work in practice? We suggest that, in principle, the precautionary principle makes good sense. In practice, however, it is imprecise in policy and law and fails to fulfil its promise because it is loosely defined and thus lacks substance and clarity. Consequently, it operates in a framework that is ambiguous, leaving it open to manipulation by discretionary powers. To counter such deficiencies, human-induced environmental harm should be formally observed as ‘criminogenic’ and environmental protection prioritised against which other competing priorities (e.g., ‘year on year’ economic growth) are measured. This would overcome the politico-legal obfuscation and contestations of climate change policy that currently impedes the precautionary principle's practical application.  相似文献   
942.
Two environmental aspects associated with land application of poultry litter that have not been comprehensively evaluated are (i) the competition of dissolved organic matter (DOM) and P for soil sorption sites, and (ii) the sorption of dissolved organic nitrogen (DON) relative to inorganic nitrogen species (e.g., NO(3)(-) and NH(4)(+)) and dissolved organic carbon (DOC). The competition between DOM and P for sorption sites has often been assumed to increase the amount of P available for plant growth; however, elevating DOM concentrations may also increase P available for transport to water resources. Batch sorption experiments were conducted to (i) evaluate soil properties governing P sorption to benchmark soils of Southwestern Missouri, (ii) elucidate the impact of poultry litter-derived DOM on P sorption, and (iii) investigate DON retention relative to inorganic N species and DOC. Soils were reacted for 24 h with inorganic P (0-60 mg L(-1)) in the presence and absence of DOM (145 mg C L(-1)) using a background electrolyte solution comparable to DOM extracts (I = 10.8 mmol L(-1); pH 7.7). Soil P sorption was positively correlated with metal oxide (r(2) = 0.70) and clay content (r(2) = 0.79) and negatively correlated with Bray-1 extractable P (r(2) = 0.79). Poultry litter-derived DOM had no significant negative impact on P sorption. Dissolved organic nitrogen was preferentially removed from solution relative to (NO(3)(-)-N + NO(2)(-)-N), NH(4)(+)-N, and DOC. This research indicates that poultry litter-derived DOM is not likely to enhance inorganic P transport which contradicts the assumption that DOM released from organic wastes increases plant-available P when organic amendments and fertilizer P are co-applied. Additionally, this work demonstrates the need to further evaluate the fate and transport of DON in agroecosystem soils receiving poultry litter applications.  相似文献   
943.
Although the 2Rs (reduce and reuse) are considered high-priority approaches, there has not been enough quantitative research on effective 2R management. The purpose of this paper is to provide information obtained through the International Workshop in Kyoto, Japan, on 11–13 November 2015, which included invited experts and researchers in several countries who were in charge of 3R policies, and an additional review of 245 previous studies. It was found that, regarding policy development, the decoupling between environmental pressures and economy growth was recognized as an essential step towards a sustainable society. 3R and resource management policies, including waste prevention, will play a crucial role. Approaches using material/substance flow analyses have become sophisticated enough to describe the fate of resources and/or hazardous substances based on human activity and the environment, including the final sink. Life-cycle assessment has also been developed to evaluate waste prevention activities. Regarding target products for waste prevention, food loss is one of the waste fractions with the highest priority because its countermeasures have significant upstream and downstream effects. Persistent organic pollutants and hazardous compounds should also be taken into account in the situation where recycling activities are globally widespread for the promotion of a material-cycling society.  相似文献   
944.
The photooxidation of fuel vapour was investigated in a smog chamber and simulated using three chemical mechanisms, the Master Chemical Mechanism (MCMv3.1), SAPRC-99 and the Carbon Bond chemical mechanism (CB05). Three varieties of fuel were used, unleaded petrol (ULP) and two ULP-ethanol blends which contained 5% and 10% ethanol (E5, E10). The fuel vapours were introduced into the chamber using two methods, by injecting the vapours from wholly evaporated fuel directly, and by injecting the headspace vapour from fuel equilibrated at 38 °C. The chamber experiments were simulated using the selected mechanisms and comparisons made with collected experimental data.The SAPRC-99 mechanism reproduced Δ(O3–NO) more accurately for almost all fuel types and injection modes, with negligible model error for both injection modes. The average model error for MCM simulations was ?16% and for CB05 the average model error was ?34%. The predictions for the CB05 mechanism varied depending on injection mode, the Δ(O3–NO) model error for wholly evaporated experiments was ?44%, compared to ?24% for headspace vapour experiments. The difference in aromatic content between experiments of different injection modes was likely to be the cause of the difference in model error for CB05. The model error for all headspace experiments was dependent upon the initial carbon monoxide concentrations.The results for Δ(O3–NO) were matched by the prediction of other key products, with formaldehyde predicted to within 20% by both SAPRC and the MCM. The addition of ethanol to the base SAPRC mechanism altered the predictions of Δ(O3–NO) by less than 2%. Changes observed in the concentrations of formaldehyde and acetaldehyde were consistent with the expected yields from ethanol oxidation.  相似文献   
945.
The Bear Brook Watershed in Maine (BBWM), USA, and the Fernow Experimental Forest in West Virginia, USA, represent unique, long-term, paired, whole watershed, experimental manipulations focusing on the effects of nitrogen (N) and sulfur (S) deposition on temperate forests. Both watersheds began whole-ecosystem additions of N and S as (NH4)2SO4 in the fall of 1989, and both are entering their third decade of chronic enrichment of the treated watersheds, while the reference watersheds offer unique opportunities to evaluate forest watershed responses to recovery. Differences between BBWM and Fernow in the history of atmospheric deposition, soil properties, and forest composition all contribute to different response trajectories in stream chemical exports over time. The four watersheds represent a spectrum of N enrichment and retention, ranging from ≈98% N retention in the reference watershed in Maine, to ≈20% N retention in the treated watershed in West Virginia. Despite these differences, there is evidence that mechanisms of response in base cation leaching and other processes are similar among all four watersheds. In both cases, the history to date of two decades of research and monitoring has provided new insights into ecosystem response not evident in more traditional short-term research.  相似文献   
946.
A scientifically valid accuracy assessment of a large-area, land-cover map is expensive. Environmental monitoring programs offer a potential source of data to partially defray the cost of accuracy assessment while still maintaining the statistical validity. In this article, three general strategies for combining accuracy assessment and environmental monitoring protocols are described. These strategies range from a fully integrated accuracy assessment and environmental monitoring protocol, to one in which the protocols operate nearly independently. For all three strategies, features critical to using monitoring data for accuracy assessment include compatibility of the land-cover classification schemes, precisely co-registered sample data, and spatial and temporal compatibility of the map and reference data. Two monitoring programs, the National Resources Inventory (NRI) and the Forest Inventory and Monitoring (FIM), are used to illustrate important features for implementing a combined protocol.  相似文献   
947.
Evaluating the overall environmental health of a region invariably involves using databases from multiple organizations. Several approaches to deal with the related technological and sociological issues have been used by various programs. Flexible data systems are required to deal with rapid changes in technology, the social and political climate for sharing and integrating data, and expectations of diverse users. Here we describe how the Environmental Monitoring and Assessment Program and the Chesapeake Bay Program manage their data for regional studies. These programs, which encompass areas of different geographic scales but face similar issues, have adopted some solutions in common, but also have tried some unique solutions suited to their needs. Understanding the tribulations and successes of these programs may help others attempting similar assessments. Both these programs have embraced distributed data systems that are managed by the organizations owning them. Both use common guidelines and policies that assure consistency and quality of data and information. These principles and tools comprise a flexible, sustainable approach that meets modern challenges of data management.  相似文献   
948.
The Reedy River in South Carolina is affected by the urban area of Greenville, the third most populous city in the state, and by the effluents from two large-scale municipal wastewater treatment plants (WWTPs) located on the river. Riverine water chemistry was characterized using grab samples collected annually under spring season baseflow conditions. During the 4-year time period associated with this study, climatic variations included two severe drought spring seasons (2001 and 2002), one above-normal precipitation spring season (2003), and one below-normal precipitation spring season (2004). The influence of drought and human activities on the baseflow chemistry of the river was evaluated by comparing concentrations of dissolved anions, total metals, and other important water chemistry parameters for these different years. Concentrations of copper and zinc, common non-point source contaminants related to urban activities, were not substantially elevated in the river within the urban area under baseflow conditions when compared with headwater and tributary samples. In contrast, nitrate concentrations increased from 1.2–1.6 mg/l up to 2.6–2.9 mg/l through the urban stream reach. Concentrations of other major anions (e.g., sulfate, nitrate) also increased along the reach, suggesting that the river receives continuous inputs of these species from within the urban area. The highest concentrations of major cations and anions typically were observed immediately downstream from the two WWTP effluent discharge locations. Attenuation of nitrate downstream from the WWTPs did not always track chloride changes, suggesting that nitrate concentrations were being controlled by biochemical processes in addition to physical processes. The relative trends in decreasing nitrate concentrations with downstream distance appeared to depend on drought versus non-drought conditions, with biological processes presumably serving as a more important control during non-drought spring seasons.  相似文献   
949.
Quantitative ground-water tracing of conduit-dominated karst aquifers allows for reliable and practical interpretation of karst ground-water flow. Insights into the hydraulic geometry of the karst aquifer may be acquired that otherwise could not be obtained by such conventional methods as potentiometric-surface mapping and aquifer testing. Contamination of karst aquifers requires that a comprehensive tracer budget be performed so that karst conduit hydraulic-flow and geometric parameters be obtained. Acquisition of these parameters is necessary for estimating contaminant fate-and-transport. A FORTRAN computer program for estimating total tracer recovery from tracer-breakthrough curves is proposed as a standard method. Estimated hydraulic-flow parameters include mean residence time, mean flow velocity, longitudinal dispersivity, Peclet number, Reynolds number, and Froude number. Estimated geometric parameters include karst conduit sinuous distance, conduit volume, cross-sectional area, diameter, and hydraulic depth. These parameters may be used to (1) develop structural models of the aquifer, (2) improve aquifer resource management, (3) improve ground-water monitoring systems design, (4) improve aquifer remediation, and (5) assess contaminant fate-and-transport. A companion paper demonstrates the use of these hydraulic-flow and geometric parameters in a surface-water model for estimating contaminant fate-and-transport in a karst conduit. Two ground-water tracing studies demonstrate the utility of this program for reliable estimation of necessary karst conduit hydraulic-flow and geometric parameters.  相似文献   
950.
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