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101.
    
With the increasing number of recycling mishaps in connection with waste electronic and electrical equipment (WEEE) in the People's Republic of China, it is imperative that the handling and recycling of WEEE be sufficiently regulated in China. Regulations covering three major issues, namely, take-back issues, controls on hazardous substances in WEEE and the assurance of good environmental management in WEEE plants, were promulgated between 2006 and 2008. The evaluation in this country report shows that few of these regulatory measures have performed satisfactorily in terms of enforcement, of public acceptance and of environmental concerns. In brief, the take-back requirements and the associated financial responsibilities are only vaguely defined; the control on hazardous substances and the so-called \"environmental expiry date\" requirements cannot be properly enforced, and the resources needed to ensure the satisfactory enforcement of the environmental abatement and pollution control requirements in WEEE plants are overwhelming. In addition, the use of a \"multiple enforcement body\" approach to the control of hazardous substances in WEEE is an indication that the Chinese government lacks the determination to properly enforce the relevant legal requirements.  相似文献   
102.
我国电网规划环境影响评价工作正处在起步阶段,缺乏成熟的理论方法和指标体系。结合常州市“十二五”电网发展规划环境影响评价工作,探讨了电网规划环评中存在的难点和问题并提出了相应的对策建议。  相似文献   
103.
通过介绍500 kV郓城~泰山紧凑型送电线路的设计,围绕输电线路走廊问题,对紧凑型线路和常规线路进行了比较,重点分析了紧凑型输电线路在提高输电能力的同时所具备的节约走廊占地和减轻电磁环境影响的技术特点.从环境保护角度来看,500 kV紧凑型输电线路是一项值得推广的技术.  相似文献   
104.
Activities beyond national park boundaries are now the principal source of threats to park natural resource integrity. Assessing the full impact of major threats as air and water pollution requires a long-term ecosystem-level approach in research design and execution, and park management. Failure to take such an approach renders most existing park data bases useless in the documentation of external threats. While the concept of managing national parks as ecosystems is not new, Park Service research and its organization have not provided the information necessary for such a basis of management. Quantifying the impacts on park resources due to external hydrologic regulation and air pollution is a good example of the need to employ an ecosystem approach in research. However, implementing such a program will require a fundamental change in research administration, priority setting, and conceptual approach.The first four of the articles in this special section arise from an AAAS symposium onExternal Threats to Ecosystems of the National Parks in the USA, which was convened in 1982. The articles have been revised to reflect subsequent developments in this field. The first article, by Dr. Stottlemyer, the symposium organizer, serves as an introduction to the topic. The fifth article in this special section was submitted separately, but included because it also is related to this particular topic.  相似文献   
105.
    
The Storm Water Management Model was used to simulate runoff and nutrient export from a low impact development (LID) watershed and a watershed using traditional runoff controls. Predictions were compared to observed values. Uncalibrated simulations underpredicted weekly runoff volume and average peak flow rates from the multiple subcatchment LID watershed by over 80%; the single subcatchment traditional watershed had better predictions. Saturated hydraulic conductivity, Manning's n for swales, and initial soil moisture deficit were sensitive parameters. After calibration, prediction of total weekly runoff volume for the LID and traditional watersheds improved to within 12 and 5% of observed values, respectively. For the validation period, predicted total weekly runoff volumes for the LID and traditional watersheds were within 6 and 2% of observed values, respectively. Water quality simulation was less successful, Nash–Sutcliffe coefficients >0.5 for both calibration and validation periods were only achieved for prediction of total nitrogen export from the LID watershed. Simulation of a 100‐year, 24‐h storm resulted in a runoff coefficient of 0.46 for the LID watershed and 0.59 for the traditional watershed. Results suggest either calibration is needed to improve predictions for LID watersheds or expanded look‐up tables for Green–Ampt infiltration parameter values that account for compaction of urban soil and antecedent conditions are needed.  相似文献   
106.
    
A method is described for the rapid survey and determination of the ecological value of woodlots. The three dominant tree species in a stand are given a visual ranking that is converted to awoodlot index through the use of species adaptation values. The woodlot index is scaled by presettlement vegetation type to yield awoodlot scale. The ecologically most valuable woodlots in a region are identified by using the woodlot scale and data on woodlot area, human disturbance, and tree density. The woodlot index corresponds closely to results from conventional methods of woodlot surveys. This method should be valuable to land-use planners for environmental impact assessment and regional planning.  相似文献   
107.
To document environmental impact predictions for land development, as required by United States government regulatory agencies, vegetation studies are conducted using a variety of methods. Density measurement (stem counts) is one method that is frequently used. However, density measurement of shrub and herbaceous vegetation is time-consuming and costly. As an alternative, the Braun-Blanquet cover-abundance scale was used to analyze vegetation in several ecological studies. Results from one of these studies show that the Braun-Blanquet method requires only one third to one fifth the field time required for the density method. Furthermore, cover-abundance ratings are better suited than density values to elucidate graphically species-environment relationships. For extensive surveys this method provides sufficiently accurate baseline data to allow environmental impact assessment as required by regulatory agencies.  相似文献   
108.
城市老工业区搬迁规划环评具有层次多、涉及面广的特点。评价首先要分清规划的层次,理清3个层面规划内容,分析所涉及到的主要环境问题,按照规划、区域和项目环评3个层次分别开展评价工作。在规划层面上应重点解决好产业发展政策的符合性和选址合理性论证;区域环评层面重点进行区域布局、结构、基础设施的支撑能力和环境的承载力评价;项目层次重点弄清污染特征、污染源和污染控制措施,评价其环境影响。  相似文献   
109.
    
Recreational impact was measured on eight beaches in Glen Canyon National Recreation Area and 15 beaches in Grand Canyon National Park using permanently located transects and plots. Recreational impact indices included densities of human trash and charcoal and a measure of sand discoloration due to charcoal. Significant increases in the indices occurred on several Glen Canyon beaches over a seven-month period. Sand discoloration became significantly higher over all Glen Canyon beaches during the same time period. All indices were significantly higher in Glen Canyon than on similar Grand Canyon beaches. These differences are probably due to differences in: (a) level of impacts tolerated by the respective management regimes and, (b) in the number of user days among the two National Park Service administrative units. Management alternatives are presented for reversing the present trends of recreational impact on Glen Canyon beaches.  相似文献   
110.
ABSTRACT: Toxicity testing is a means of establishing the environmental risk of a uranium tailings release. It is valuable in designing tailings containment structures because it assists in setting acceptable levels of risk for the design. This paper presents details of toxicity tests of the tailings from Ranger Uranium Mine, Northern Territory, Australia. The results suggest that the non-radiological toxicity of the tailings is low. The environmental risk of a tailings release is more likely to be related to the physical impacts of the tailings, including infilling of billabongs and changes in the sedimentology of riparian ecosystems rather than their biogeochemical impact. Two major results were: (1) water from treatment with washed tailing fines were not toxic to Hydra viridissima, and (2) mixtures of washed tailings fines and natural floodplain sediment (overlying water or elutriates) were not toxic to Hydra viridissima or Moinodaphnia macleayi.  相似文献   
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