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1.
    
ABSTRACT: The Tualatin is the first watershed in Oregon to implement the Total Maximum Daily Load provisions of the Clean Water Act to deal with nonpoint source pollution. Local officials cite residential yard care practices as potential contributors to nonpoint source pollution in the basin. Qualitative and quantitative methods, including observation of yard maintenance styles, suggest behaviors potentially harmful to water quality and conservation. Yard maintenance is influenced by the importance of neighborhood appearance and concern for aesthetics. These concerns stimulate residents to water, fertilize, and apply weed control at more frequent intervals than yard care experts recommend. Better understanding of the effects that relations with neighbors and yard maintenance knowledge have on residential yard care practices can help improve water quality.  相似文献   

2.
城市生态系统恢复研究进展   总被引:1,自引:0,他引:1  
定义了城市生态系统恢复的概念,分析了全球城市生态系统恢复状况,总结了城市生态系统恢复的研究进展,指出了城市生态系统恢复科学的研究方向.  相似文献   

3.
    
This paper provides additional empirical knowledge of injustice embedded in the urban governance of informal-sector electronic waste (e-waste) recycling in Ghana. It uses Urban Political Ecology and Environmental Justice perspectives to explain how divergent interest and power among diverse actors in the e-waste sector engender social and environmental (in)justice in Accra. Using the case study approach, this paper reveals that the persistent struggles over interest and power which characterise the governance and management of informal e-waste recycling generate inequity, false accusations, misrecognition, disrespect, devaluation, neglect, exclusion, and abuse of freedom and rights. Inclusive of the finding is the development of local resistance and social movement in defence of interests and against state aggression, oppression, domination and neglect. The study concludes to suggest that the governance of urban socio-economic and ecological space of Accra should involve coordination, participation, holistic inclusion of diverse interest, so as to minimise trade-offs and reap synergies.  相似文献   

4.
城市水源污染状况及其保护措施   总被引:3,自引:0,他引:3  
通过对我国城市水源功能区的划分、城市水源污染情况的现状分析,重点介绍了当前国内外一些国家与城市在水源保护上的成功做法,并提出:具有合理的生物多样性和种群结构、健康的营养结构及正常能量代谢的水生态系统,是衡量水源水质良好的重要标准。  相似文献   

5.
    
Very few studies have addressed the effects of water quality on recreational values in a hedonic property price setting. This study elicits the value of improved water quality capitalised in Finnish recreational property prices adjacent to the Baltic Sea, lakes and rivers. In addition, spatial econometric methods are employed to address the spatial autocorrelation found in data. An expert-determined, water body specific water quality index that describes the usability status of the water is used instead of more specific, but also more problematic, water quality indicators. The study finds that water usability has a positive effect on property prices, with weak suggestions on non-linearity.  相似文献   

6.
Since 1961, control over water-supply interference problems in the Province of Ontario has been provided under The Ontario Water Resources Commission Act. A section of The Act requires persons taking more than 10,000 imperial gallons per day of water for purposes other than domestic, stock or fire-fighting to have a permit and to take the water in accordance with specified terms and conditions. Construction of some new wells, sewers, and roads to meet the needs of urban development has caused interference with both ground- and surface-water supplies. In cases of serious interference, the Commission has required that steps be taken to restore water supplies or prevent continued interference. Two cases are described where municipalities in the Toronto area restored supplies to overcome serious interference with several private wells and streamflow during testing and operation of a 500-imperial gpm municipal well adjacent to a normally effluent stream, and varying degrees of interference with private wells caused by dewatering at rates up to 2000-imperial gpm for the installation of a trunk sewer.  相似文献   

7.
Poff, Boris, Karen A. Koestner, Daniel G. Neary, and Victoria Henderson, 2011. Threats to Riparian Ecosystems in Western North America: An Analysis of Existing Literature. Journal of the American Water Resources Association (JAWRA) 47(6):1241–1254. DOI: 10.1111/j.1752‐1688.2011.00571.x Abstract: A total of 453 journal articles, reports, books, and book chapters addressing threats to riparian ecosystems in western North America were analyzed to identify, quantify, and qualify the major threats to these ecosystems as represented in the existing literature. Publications were identified either as research, policy, literature review, historical comparison, or management papers. All papers were evaluated based on year of publication, area of interest, and type(s) of threats addressed. Research papers, however, were assessed in more depth. The publications ranged from the 1930s to 2010 and addressed the following threats: dams, pollution (point and nonpoint), grazing, land use change, timber harvesting, water diversion, road construction, recreation, mining, groundwater pumping, invasive species, climate change, salinity, fire, insect and diseases, woody encroachment, watershed degradation, elimination of native vegetation, beavers, fire suppression, and fuel management. While the types of threats vary on spatial and temporal scales, some persist through decades in western North America. This analysis shows that grazing has been perceived as a dominant threat since the 1980s, but has been diminishing in the past decade, while invasive species, dams and, in recent years, climate change are increasingly represented in the literature as threats to riparian ecosystems in western North America.  相似文献   

8.
ABSTRACT: A great deal of information can be derived from study of standard stream monitoring data, if these are properly ordered and organized. This information may then be used to make decisions about water quality management. Among critical information items are evaluation of performance to standards, determination of seasonality and time-trends of water quality conditions, and estimation of the effects on water quality to be expected from load reductions or standards modifications. Additional information on the magnitude of individual pollution sources is also critical to water quality management. Each of these items can be derived within the water quality information system which is currently under development for the State of Illinois.  相似文献   

9.
ABSTRACT Using water analyses from 67 gaging stations, discharge-frequency-weighted mean concentrations (QFC) and average annual yield (AAY) per unit area were determined for the total dissolved mineral content of Illinois streams. The resultant data indicates that total dissolved mineral contents are controlled by regional rather than local factors. In most cases plausible explanation for the magnitudes can be found in regional patterns of natural and demographic conditions. Although the data suggest that total dissolved minerals are increasing, the relative contributions of natural versus anthropogenic phenomena are difficult to delimit at this level of investigation.  相似文献   

10.
    
ABSTRACT: Regression models are presented that can be used to estimate mean loads for chemical oxygen demand, suspended solids, dissolved solids, total nitrogen, total ammonia plus nitrogen, total phosphorous, dissolved phosphorous, total copper, total lead, and total zinc at unmonitored sites in urban areas. Explanatory variables include drainage area, imperviousness of drainage basin to infiltration, mean annual rainfall, a land-use indicator variable, and mean minimum January temperature. Model parameters are estimated by a generalized-least-squares regression method that accounts for cross correlation and differences in reliability of sample estimates between sites. The regression models account for 20 to 65 percent of the total variation in observed loads.  相似文献   

11.
ABSTRACT: Optimal policies for supplying rapidly expanding urban centers with additional water supplies are shown to be dependent on water quality goals for the urban effluent. As effluents are required to meet increasingly stringent standards, the unit costs associated with adding capacity to existing wastewater treatment systems to renovate some waters for reuse are shown to substantially decrease. A nonlinear elimination algorithm is developed to delineate optimal policies. A model employing the technique was applied to the wastewater treatment system of a typical urban system and the water quality objectives varied. A comparison of costs with and without various levels of reuse were made and unit costs of reused water under these conditions determined.  相似文献   

12.
    
ABSTRACT: Intensive temporal sampling of rainfall, surface runoff and subsurface drainage, and stream flow upstream and downstream of a suburban mall parking lot yielded expected patterns in time and space. Variations in temperature and conductivity showed strong dilution effects, while patterns of nine elemental concentrations in surface runoff showed a flushing effect early in the storm, following by dilution. Heavy nitrate loads in surface runoff were apparently from rainfall, not surficial sources. For the magnitude of storm studied and the existing study site, local impact on stream flow and water quality, like the run-off itself, is rather ephemeral, and dissipates after about five hours.  相似文献   

13.
    
ABSTRACT: This paper presents the results of a study on the use of continuous stage data to describe the relation between urban development and three aspects of hydrologic condition that are thought to influence stream ecosystems—overall stage variability, stream flashiness, and the duration of extreme‐stage conditions. This relation is examined using data from more than 70 watersheds in three contrasting environmental settings—the humid Northeast (the metropolitan Boston, Massachusetts, area); the very humid Southeast (the metropolitan Birmingham, Alabama, area); and the semiarid West (the metropolitan Salt Lake City, Utah, area). Results from the Birmingham and Boston studies provide evidence linking increased urbanization with stream flashiness. Fragmentation of developed land cover patches appears to ameliorate the effects of urbanization on overall variability and flashiness. There was less success in relating urbanization and streamflow conditions in the Salt Lake City study. A related investigation of six North Carolina sites with long term discharge and stage data indicated that hydrologic condition metrics developed using continuous stage data are comparable to flow based metrics, particularly for stream flashiness measures.  相似文献   

14.
A reduction in the legitimacy of top-down governance approaches has resulted in many government agencies using decentralised governance approaches, including localism. However, the effective implementation of localism is challenging. Localism aims to encourage innovative context-based solutions; however unanticipated implementation problems often constrain localism outcomes. There is a significant gap in our understanding of localism in practice, with a better understanding essential to improve localism design and implementation. This paper contributes to addressing this gap through an empirical examination of localism in action. Using the CLEAR framework, we evaluate the decentralised governance of environmental water in the Australian state of New South Wales, a contentious, uncertain and multi-level governance environment. Qualitative interviews with 58 Environmental Water Advisory Group members identified barriers to an effective localism approach, including issues of access and capacity development, transparency of decision-making outcomes and power inequities. This understanding enables the development of strategies for improved localism practice.  相似文献   

15.
ABSTRACT: Diseases in wild fish populations may have multiple economic and social impacts. Epidemics of infectious diseases, which are associated with the presence of some microbe or parasite, have recently been observed in several major estuarine systems in the eastern United States. The most prevalent of these problems is ulcerative mycosis (UM), a fungal infection. The agents responsible for UM and many of these other diseases are opportunistic pathogens that are not believed to infect normal, immunocompetent individuals. While inroads have been made into determining the infectious agents associated with these diseases, we know very little of how pollution may influence their prevalence. Understanding the importance of pollution requires an awareness of all the environmental conditions that can affect the health of wild populations. In this paper, a multistep examination of the interactions between the host, pathogen(s), and environment is outlined.  相似文献   

16.
    
ABSTRACT: Analysis of the storage-yield relationship can be used to help resolve conflicts between environmental values and water resources development. New Melones Reservoir in northern California presents a classic example of such a conflict between preservation of white water for recreational purposes and development of the site for a major multi-purpose reservoir. Analysis of the storage yield relationship for the proposed New Melones project indicates potential trade-offs between white water preservation and reservoir yield.  相似文献   

17.
近年来氨氮污染对宁夏水环境质量的影响日趋严重,本文通过大量的监测数据,分析了水环境中氨氮污染现状及其变化趋势,研究了氨氮污染物的来源和分布,并在此基础上提出了控制氨氮污染的对策。  相似文献   

18.
ABSTRACT: Precipitation and resultant runoff were sampled for a series of storm events over the period of one year. The test site was the parking lot of a large suburban shopping mall in the Syracuse, New York, area. Both precipitation and runoff were tested for lead, zinc, copper, cadmium, and petroleum hydrocarbons: substantial amounts were detected in each. No correlation was found between precipitation contaminant concentration and the length of the antecedent dry period. A weak, but apparently inverse relationship was noticed between concentration and amount of precipitation. Poor correlations were obtained between runoff contaminant concentration and the antecedent dry period. The variability attributable to different precipitation volumes was removed by converting to a unit-area basis. The variability attributable to precipitation contaminant load was removed by subtraction. The resultant value, dryfall accumulation, then correlated well with the length of the antecedent dry period. Metal ions were found in both precipitation and runoff and were hypothesized to come from atmospheric fallout as a result of distant emissions and from very localized sources, primarily vehicle traffic on the parking facility. Petroleum residues were believed to be the sole result of automobile losses, since none could be detected in precipitation samples.  相似文献   

19.
王静  魏雅钦  鲁艺玲  张超 《四川环境》2022,41(1):154-162
为研究地震前后地表水水质变化规律,以2013年4月20日雅安地震重灾区—宝兴县地表水水质变化为例,对2012 ~2019年宝兴县赵家坝断面地表水水质监测数据收集整理,单因子评价法、污染指数法(单项污染指数、综合污染指数和有机污染综合指数)和水质指数模式优化法对地震前后地表水质进行分析.结果 表明,此次地震引起水体中污染...  相似文献   

20.
通过大量历年数据,对绵远河水环境质量的变化进行定量、定性分析,表明绵远河水环境质量日趋恶化,必须加快实施综合整治步伐。  相似文献   

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