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1.
The long-term recovery process for fish communities in a warm water stream in East Tennessee was studied using quantitative measurements over 20 years. The stream receives effluents from a U. S. Department of Energy (DOE) facility, but since 1985 these effluents have been greatly reduced, eliminated, or diluted as part of a substantial long-term pollution abatement program. The resulting changes in water quantity and quality led to a recovery of the fish communities, evidenced by significant changes in species richness, abundance (density and biomass), and community composition (e.g., number of fish species sensitive to stress). The fish community changes occurred over a spatial gradient (downstream from the headwater release zone nearest the DOE facility) and temporally, at multiple sampling locations in the stream. Changes in measured parameters were associated with specific remedial actions and the intervening steps within the recovery process are discussed with regard to changes in treatment processes.  相似文献   

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南四湖流域水环境承载力评价指标体系构建   总被引:2,自引:0,他引:2  
针对目前水环境承载力概念及评价指标体系研究中存在的问题,构建了流域水环境承载力概念模型,根据评价指标筛选原则,建立了南四湖流域水环境承载力评价指标体系,包括水环境承载能力、水环境压力、水环境承载状态和社会经济调控能力4部分,共有57个具体指标,从而为制定流域保护规划和管理政策提供技术支持,为寻求流域水环境承载力的提高途径和措施提供科学依据。  相似文献   

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邛海水质变化趋势及保护对策研究   总被引:1,自引:0,他引:1  
本文通过对邛海流域现状污染源进行调查,邛海流域COD、氨氮、总氮和总磷产生量分别为5892.1t/a、995.6t/a、2888.2t/a和1105.1t/a,污染负荷主要来自面源污染.通过2002 ~ 2011年邛海水质监测数据分析,邛海水质近10年总体保持Ⅱ~Ⅲ类,处于中营养状态,2004~ 2006年水质相对较差,2006年以后水质逐渐好转.总磷、总氮是邛海主要污染因子,海河口是邛海污染最严重的区域.为实现邛海水质和流域生态环境持续改善,从产业结构优化、流域污染源治理、生态保育和流域生态环境综合监管等方面提出对策建议.  相似文献   

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黄河流域生态系统服务变化的定量评估有利于考核流域生态综合治理效果。本研究构建了基于能值的生态系统服务价值核算方法体系,核算了黄河流域2000—2015年省级及地市级尺度生态系统服务价值变化及导致变化的原因。结果表明:(1)近15年,黄河流域生态状况有明显好转,除河南和山东外,增幅主要集中在黄河流域的中上游(7%~27%),增幅最大的为甘肃;(2)黄河流域的117个地级市(地区、自治州、盟)中,有77个地级市(地区、自治州、盟)生态系统服务价值有不同增幅(0.46%~210%);(3)黄河流域"源""过程""汇"区位不同保护重点不同,要根据其所提供生态服务的能力及改善情况动态制定分区分类保护策略;(4)近15年的林地面积增加对所提供的服务提升效果明显,湿地(湖泊、沼泽地)的减少变成黄河流域上、中、下游省份服务下降的最大驱动因素。本研究能够为黄河流域生态治理及城市绿色发展提供基础性依据。  相似文献   

6.
We used invertebrate bioassessment, habitat analysis, geographic information system analysis of land use, and water chemistry monitoring to evaluate tributaries of a degraded northeast Nebraska, USA, reservoir. Bimonthly invertebrate collections and monthly water chemistry samples were collected for two years on six stream reaches to identify sources contributing to reservoir degradation and test suitability of standard rapid bioassessment methods in this region. A composite biotic index composed of seven commonly used metrics was effective for distinguishing between differentially impacted sites and responded to a variety of disturbances. Individual metrics varied greatly in precision and ability to discriminate between relatively impacted and unimpacted stream reaches. A modified Hilsenhoff index showed the highest precision (reference site CV = 0.08) but was least effective at discriminating among sites. Percent dominance and the EPT (number of Ephemeroptera, Plecoptera, and Trichoptera taxa) metrics were most effective at discriminating between sites and exhibited intermediate precision. A trend of higher biotic integrity during summer was evident, indicating seasonal corrections should differ from other regions. Poor correlations were evident between water chemistry variables and bioassessment results. However, land-use factors, particularly within 18-m riparian zones, were correlated with bioassessment scores. For example, there was a strong negative correlation between percentage of rangeland in 18-m riparian zones and percentage of dominance in streams (r 2 = 0.90, P < 0.01). Results demonstrate that standard rapid bioassessment methods, with some modifications, are effective for use in this agricultural region of the Great Plains and that riparian land use may be the best predictor of stream biotic integrity.  相似文献   

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Sustainability and welfare are concepts that are often mentioned in the context of fishing and fish farming. What these concepts imply in practice, how they are defined and made operational is less clear. This paper focuses on the role of fish buyers as a key actor in the supply chain between the fisher or fish farmer and the consumer. Using semi-structured interviews, we explore and analyze whether and how the interviewed fish buyers define and implement moral values related to animal welfare and sustainability. The eight fish buyers who were interviewed suggest that moral values are used in their work, but also result in a number of value conflicts (moral and non-moral). The focus on sustainability and animal welfare appear to be driven by external and market factors. Sustainability mainly reflects fishing methods and quotas and fish welfare is seen as part of sustainability. Fish welfare seems more important for farmed than for wild fish as the buyers feel a responsibility regarding these kept animals. Further, the decision whether a product is sustainable is mainly based on labels. Fish buyers argue that labels are useful as a business-to-business tool. Nonetheless, based on the interviews, we argue that the relevance of these labels for addressing the ethical dilemmas of buyers is limited. Labels often are a rather procedural solution that deals with the genuine dilemmas only to a limited extent. We conclude that in order to move forward, the sector needs to further reflect and elaborate on its core values.  相似文献   

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In the spring and summer of 2017, communities along the Lake Ontario shoreline suffered from the worst flood event on record. In late May, daily water levels reached their highest point in over 100 years, and flooding continued throughout much of the summer as lake levels slowly declined, with inundation and erosion significantly impacting shoreline homes and businesses. In this work, we present results from a rapid response online survey of property owners along the New York Lake Ontario shoreline to quantify the perceived flood impacts of the 2017 extended high water event. The survey focused on the degree and spatial distribution of inundation and erosion; the duration and drivers of inundation; the associated damages to different property features, with an emphasis on shoreline protection; and the degree of disruption to business and other activities and services. Photographic documentation of inundation extent and property damage also was provided by survey respondents. We demonstrate the potential utility of this dataset by characterizing key features of inundation and erosion impacts across the shoreline, and by using classification and regression trees to explore the predictability of inundation and erosion based on property characteristics. This work is part of a larger effort to develop models of inundation and erosion that can support flood impact assessments across the shoreline and help communities better prepare for future extended high water events.  相似文献   

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This paper reviews recent declines in fish resources and fishing communities in Korea, evaluates major factors of declines, and examines a subsequent community-based revitalization project. Factors leading to depleting fish resources include global regulations, technological advances in fishing, national economic development policies, land reclamation projects, and pollution. The negative economic and societal impact of depleting fish resources is addressed using demographic and income levels of the communities. In response, the state initiated revitalization projects and invested in local fishing cooperatives promoting community-based management. The result has been less than effective as it led to mismanagement of investment and created an attitude of dependence on the government for financial assistance.  相似文献   

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根据沂沭河流域的水文特征和水质状况,建立了沂沭河流域河流水环境容量数学模型和计算方法,依据该流域水环境功能区划,计算出流域内各水功能区和各河流的环境容量及最大允许排污量,从而为沂沭河流域实施水污染物总量控制和南水北调东线工程山东段水质达标提供基础数据。  相似文献   

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南四湖流域水污染防治存在的问题及对策   总被引:1,自引:0,他引:1  
南四湖通过采用"治、用、保"并举的流域污染综合治理措施,把污染治理与水资源循环利用相结合,取得了明显的成效,但仍面临工业结构性污染严重、城市基础设施建设滞后、面源污染突出等问题。根据南四湖实际情况,可从加大资金筹措力度、继续实施流域综合治理、整合现有港口资源、开展生态养殖、加强执法等方面入手,解决流域水污染防治存在的问题。  相似文献   

16.
Abstract

Climate change is a major issue for all levels of government, global, national and local. Local authorities' responses to climate change have tended to concentrate on their role in reducing greenhouse gases. However, the scientific consensus is that we also need to adapt to unavoidable climate change. Spatial planning at a local level has a critical anticipatory role to play in promoting robust adaptation. This paper reviews the shift in local authorities' planning policies for climate change adaptation in the UK since 2000, and provides evidence of underlying attitudes amongst planning professionals to climate change. It shows that, while the issue of climate change is becoming recognized with respect to flood risk, the wider implications (for instance, for biodiversity and water resources) are not yet integrated into plans. The reasons for this lie in lack of political support and lack of engagement of the planning profession with climate change networks. But the paper also argues there are difficulties in acknowledging the need for adaptation at the local level, with the short-term horizons of local plans at odds with perceptions of the long-term implications of climate change.  相似文献   

17.
Climate change is a major issue for all levels of government, global, national and local. Local authorities' responses to climate change have tended to concentrate on their role in reducing greenhouse gases. However, the scientific consensus is that we also need to adapt to unavoidable climate change. Spatial planning at a local level has a critical anticipatory role to play in promoting robust adaptation. This paper reviews the shift in local authorities' planning policies for climate change adaptation in the UK since 2000, and provides evidence of underlying attitudes amongst planning professionals to climate change. It shows that, while the issue of climate change is becoming recognized with respect to flood risk, the wider implications (for instance, for biodiversity and water resources) are not yet integrated into plans. The reasons for this lie in lack of political support and lack of engagement of the planning profession with climate change networks. But the paper also argues there are difficulties in acknowledging the need for adaptation at the local level, with the short-term horizons of local plans at odds with perceptions of the long-term implications of climate change.  相似文献   

18.
徐州市云龙湖富营养化特征分析与评价   总被引:1,自引:0,他引:1  
利用相关指标(叶绿素a、总磷、总氮、透明度、浮游植物密度等)分析了徐州市云龙湖水体的富营养化特征,表明磷是藻类代谢的限制性营养盐。采用综合营养状态指数法评价了湖水富营养化程度,结果显示云龙湖水体呈轻度富营养化状态,结合近10年来的评价结果分析了云龙湖水体富营养化的变化趋势。  相似文献   

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采用博弈论的分析方法寻找南四湖流域生态补偿主客体的纳什均衡。在静态博弈模型和动态博弈模型得出两个截然不同的均衡:静态博弈的均衡是(不保护,不补偿),动态博弈的均衡是(保护,补偿)。在静态博弈中进行激励设计,提高补偿客体保护水资源的积极性,实现帕累托最优,应该立法,制定严格的惩罚标准;动态分析是建立在完全信息的基础上,由此要求政府建立良好的信誉,才能保证均衡的长久,从而达到保护南四湖流域生态环境的目的。  相似文献   

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