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141.
Human Influences on Water Quality in Great Lakes Coastal Wetlands   总被引:2,自引:0,他引:2  
A better understanding of relationships between human activities and water chemistry is needed to identify and manage sources of anthropogenic stress in Great Lakes coastal wetlands. The objective of the study described in this article was to characterize relationships between water chemistry and multiple classes of human activity (agriculture, population and development, point source pollution, and atmospheric deposition). We also evaluated the influence of geomorphology and biogeographic factors on stressor-water quality relationships. We collected water chemistry data from 98 coastal wetlands distributed along the United States shoreline of the Laurentian Great Lakes and GIS-based stressor data from the associated drainage basin to examine stressor-water quality relationships. The sampling captured broad ranges (1.5–2 orders of magnitude) in total phosphorus (TP), total nitrogen (TN), dissolved inorganic nitrogen (DIN), total suspended solids (TSS), chlorophyll a (Chl a), and chloride; concentrations were strongly correlated with stressor metrics. Hierarchical partitioning and all-subsets regression analyses were used to evaluate the independent influence of different stressor classes on water quality and to identify best predictive models. Results showed that all categories of stress influenced water quality and that the relative influence of different classes of disturbance varied among water quality parameters. Chloride exhibited the strongest relationships with stressors followed in order by TN, Chl a, TP, TSS, and DIN. In general, coarse scale classification of wetlands by morphology (three wetland classes: riverine, protected, open coastal) and biogeography (two ecoprovinces: Eastern Broadleaf Forest [EBF] and Laurentian Mixed Forest [LMF]) did not improve predictive models. This study provides strong evidence of the link between water chemistry and human stress in Great Lakes coastal wetlands and can be used to inform management efforts to improve water quality in Great Lakes coastal ecosystems.  相似文献   
142.
There are always conflicting goals in the management of large water courses. However, by involving stakeholders actively in the planning and decision-making processes, it is possible to work together toward commonly acceptable solutions. In this article, we describe how we applied interactive multicriteria decision analysis (MCDA) in a collaborative process which aimed at an ecologically, socially, and economically sustainable water course regulation policy. The stakeholders' opinions about the alternative regulation schemes and the relative importance of their impacts were elicited with the HIPRE software. Altogether, 20 personal interactive decision analysis interviews (DAIs) were carried out with the stakeholders. Our experience suggests that the DAIs can considerably improve the quality and efficiency of the collaborative planning process. By improving communication and understanding of the decision situation in the steering group, the approach helped to develop a consensus solution in a case having strong conflicts of interest. In order to gain the full benefits of the MCDA approach, interactive preference elicitation is vital. It is also essential to integrate the approach tightly into the planning and decision-making process. The project's home pages are available to the public at http://www.paijanne.hut.fi/.  相似文献   
143.
In this paper the results of a thorough evaluation of the environmental fate and effects of azilsartan are presented. Azilsartan medoxomil is administered as a pro-drug for the treatment of patients with essential hypertension. The pro-drug is converted by hydrolysis to the active pharmaceutical ingredient azilsartan. Laboratory tests to evaluate the environmental fate and effects of azilsartan medoxomil were conducted with azilsartan and performed in accordance with OECD test guidelines. The predicted environmental concentration (PEC) in surface water was estimated at 0.32 μg L−1 (above the action limit of 0.01 μg L−1), triggering a Phase II assessment. Azilsartan is not readily biodegradable. Results of the water sediment study demonstrated significant shifting of azilsartan metabolites to sediment. Based on the equilibrium partitioning method, metabolites are unlikely to pose a risk to sediment-dwelling organisms. Ratios of the predicted environmental concentrations (PECs) to the predicted-no-effect concentrations (PNECs) did not exceed the relevant triggers, and the risk to aquatic, sewage treatment plant (STP), groundwater and sediment compartments was concluded acceptable. A terrestrial assessment was not triggered. Azilsartan poses an acceptable risk to the environment.  相似文献   
144.
Major benefits were weighed against major costs associated with recent saltcedar control efforts along the Middle Pecos River, New Mexico. The area of study was restricted to both sides of the channel and excluded tributaries along the 370 km between Sumner and Brantley dams. Direct costs (helicopter spraying, dead tree removal, and revegetation) within the study area were estimated to be $2.2 million but possibly rising to $6.4 million with the adoption of an aggressive revegetation program. Indirect costs associated with increased potential for erosion and reservoir sedimentation would raise the costs due to increased evaporation from more extensive shallows in the Pecos River as it enters Brantley Reservoir. Actions such as dredging are unlikely given the conservative amount of sediment calculated (about 1% of the reservoir pool). The potential for water salvage was identified as the only tangible benefit likely to be realized under the current control strategy. Estimates of evapotranspiration (ET) using Landsat TM data allowed estimation of potential water salvage as the difference in ET before and after treatment, an amount totaling 7.41 million m3 (6010 acre-ft) per year. Previous saltcedar control efforts of roughly the same magnitude found that salvaged ET recharged groundwater and no additional flows were realized within the river. Thus, the value of this recharge is probably less than the lowest value quoted for actual in-channel flow, and estimated to be < $63,000 per year. Though couched in terms of costs and benefits, this paper is focused on what can be considered the key trade-off under a complete eradication strategy: water salvage vs. erosion and sedimentation. It differs from previous efforts by focusing on evaluating the impacts of actual control efforts within a specific system. Total costs (direct plus potential indirect) far outweighed benefits in this simple comparison and are expected to be ongoing. Problems induced by saltcedar control may permanently reduce reservoir capacity and increase reservoir evaporation rates, which could further deplete supplies on this water short system. These potential negative consequences highlight that such costs and benefits need to be considered before initiating extensive saltcedar control programs on river systems of the western United States.  相似文献   
145.
随着生态矛盾不断突出,各地政府将实现生态治理合作共赢作为生态环境治理的目标。如何在治理生态合作的过程中使得参与博弈各方的利益冲突达到合理稳定是决定生态合作能否顺利开展的关键。以往关于生态合作的演化博弈研究更多的侧重于探讨跨区域生态合作中各地方政府间的演化博弈,忽略了国家建立的监管机制在生态合作中的重要作用。该文构建监管机制和地方政府动态演化博弈模型进行相关利益主体的博弈分析,利用模型得到各种策略选择下监管机制和地方政府的期望收益,再通过复制动态方程,计算出各自的演化稳定策略。研究表明:监管机制提供适当的财政补贴对于促进生态合作至关重要;地方政府参与生态合作得到的直接收益是地方政府是否参与生态合作的关键因素;国家应该着力规划合理生态合作机制,使各地方政府参与生态合作的同时获得生态合作产业发展带来的额外效益;通过引进高新技术,对新技术产业加以扶持和政策优惠,降低当地政府创新企业技术的成本,使生态合作可以高效运转,实现可持续发展。  相似文献   
146.
Trace elements were analyzed in fish of commercial interest to determine their importance in marine systems of the Western Indian Ocean and their bioaccumulation patterns. The results are equivalent or lower than levels reported in ichthyofauna worldwide. Certain values of muscular Cd, Hg, Pb and Zn were, however, above thresholds for human consumption. Levels varied among tissues, species and fish length, but were seldom influenced by the nutritional condition of the fish, its gender and its reproductive status. Correlations between hepatic Hg and Se levels in Swordfish (r2=0.747) and Yellowfin Tunas (r2=0.226), and among metallothionein linking metals imply the existence of detoxification processes in these species. Level differences between fish from the Mozambique Channel and Reunion Island reflect differences of diets rather than differences of elemental availability in both environments.  相似文献   
147.
The Savannah River National Laboratory (SRNL) Weather Information and Display System was used to provide meteorological and atmospheric modeling/consequence assessment support to state and local agencies after the collision of two Norfolk Southern freight trains on the morning of January 6, 2005. This collision resulted in the release of several toxic chemicals to the environment, including chlorine. The dense and highly toxic cloud of chlorine gas that formed in the vicinity of the accident was responsible for 9 fatalities and caused injuries to more than 500 others. Transport model results depicting the forecast path of the ongoing release were made available to emergency managers in the county's Unified Command Center shortly after SRNL received a request for assistance. Support continued over the ensuing 2 days of the active response. The SRNL also provided weather briefings and transport/consequence assessment model results to responders from the South Carolina Department of Health and Environmental Control, the Savannah River Site (SRS) Emergency Operations Center, Department of Energy headquarters, and hazard material teams dispatched from the SRS. Operational model-generated forecast winds used in consequence assessments conducted during the incident were provided at 2-km horizontal grid spacing during the accident response. High-resolution Regional Atmospheric Modeling System (RAMS, version 4.3.0) simulation was later performed to examine potential influences of local topography on plume migration in greater detail. The detailed RAMS simulation was used to determine meteorology using multiple grids with an innermost grid spacing of 125 m. Results from the two simulations are shown to generally agree with meteorological observations at the time; consequently, local topography did not significantly affect wind in the area. Use of a dense gas dispersion model to simulate localized plume behavior using the higher-resolution winds indicated agreement with fatalities in the immediate area and visible damage to vegetation.  相似文献   
148.
室内不同条件与甲醛TVOC污染关系分析   总被引:1,自引:1,他引:0  
文章通过对255个调查监测数据的分析,初步探讨不同环境条件(温度和湿度),装修时间以及装修条件(家具类型、地面材料、墙面材料和顶面材料)对室内空气中甲醛、TVOC浓度的影响,得出在高温湿度大的情况下,甲醛释放量明显增大。要减少室内空气的污染,须注意各种装饰材料的合理搭配,充分考虑房屋空间承载量和室内通风量,并尽可能延长入住或办公时间。  相似文献   
149.
建立了一种用气相色谱法准确、快速测定垃圾渗出液中酚类物质的新方法。外标法定量分析 4 -甲基苯酚及苯酚。采用填装了 80~ 1 0 0目 Chromosorb WAW DCMS的玻璃填充柱 ,担体上涂渍了 2 % OV-1 7,2 .5% QF-1的固定液 ,分离酚类物质效果较好 ,线性范围为 1 0 0~ 1 50 0 mg/ L,相关系数为 0 .9996,方法回收率为 94 .7%。  相似文献   
150.
The United States National Institute for Occupational Safety and Health, through an informal partnership with industry, labor, and the United States Mine Safety and Health Administration, has developed and tested a new instrument known as the Personal Dust Monitor (PDM). The new dust monitor is an integral part of the cap lamp that coal miners normally carry to work and provides continuous information about the concentration of respirable coal mine dust within the breathing zone of that individual. Previous laboratory testing demonstrated that there is a 95% confidence that greater than 95% of individual PDM measurements fall within +/-25% of reference measurements. The work presented in this paper focuses on the relationship between the PDM and respirable dust concentrations currently measured by a coal mine dust personal sampler unit utilizing a 10 mm Dorr-Oliver nylon cyclone. The United Kingdom Mining Research Establishment instrument, used as the basis for coal mine respirable dust standards, had been designed specifically to match the United Kingdom British Medical Research Council (BMRC) criterion. The personal sampler is used with a 1.38 multiplier to convert readings to the BMRC criterion. A stratified random sampling design incorporating a proportionate allocation strategy was used to select a sample of mechanized mining units representative of all US underground coal mines. A sample of 180 mechanized mining units was chosen, representing approximately 20% of the mechanized mining units in production at the time the sample was selected. A total of 129 valid PDM/personal sampler dust sample sets were obtained. A weighted linear regression analysis of this data base shows that, in comparison with the personal sampler, the PDM requires a mass equivalency conversion multiplier of 1.05 [95% C.I.=(1.03, 1.08)] when the small intercept term is removed from the analysis. Removal of the intercept term results in a personal sampler-equivalent concentration increase of 2.9% at a PDM measurement of 2.0 mg m(-3).  相似文献   
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