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881.
就大气环境影响评价中理解和执行GB/T13201-91、GB3095-82的几个问题提出了看法和建议。 相似文献
882.
Ted L. Ernst Nancy C. Leibowitz Denis Roose Steve Stehman N. Scott Urquhart 《Environmental management》1995,19(1):99-113
The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) will monitor the
nation's resources by evaluating the status and trends of selected indicators of condition using a probability-based sampling
design. The EMAP-Wetlands program will monitor the condition of the nation's wetlands. The EMAP classification system is an
aggregation of the many subclasses of the US Fish and Wildlife Service's National Wetlands Inventory (NWI) classification
system. This aggregation results in fewer wetland classes with more wetlands per class than the NWI system. Aggregation of
the NWI classification was based primarily on dominant vegetation cover, flooding regimes, dominant water source, and adjacency
to rivers and lakes. We evaluated the EMAP classification system and sampling design using NWI digital wetlands data for portions
of Illinois, Washington, North Dakota, and South Dakata. Relative numbers of wetlands, total areas, average areas, and common
versus rare classes were compared between the EMAP and NWI classification systems. As expected, the EMAP classification provided
fewer wetland polygons, each with larger areas, without altering total wetland area. Summary statistics comparing sample estimates
to true population parameters (represented by the NWI data) demonstrated the effectiveness of the EMAP sampling design with
the exception of rare EMAP classes in the selected regions. Although simple random sampling is inadequate for both large and
small wetlands, the EMAP sampling design is readily adapted to provide better estimates for these categories. Aggregating
the NWI classification to the EMAP classification provides fewer wetland classes, with more wetlands per class, for EMAP's
annual reports and statistical summaries.
The research in this report has been funded by the United States Environmental Protection Agency (EPA) under contracts 68-C8-0006
to ManTech Environmental Technology, Inc. and 68-03-3532 to The Bionetics Corporation. Mention of trade names does not constitute
endorsement or recommendation for use. 相似文献
883.
Mike Danson 《Journal of Environmental Planning and Management》1991,34(2):89-95
This paper describes the recent economic history of the Scottish economy and uses a synthesised theory of labour market segmentation and the dual economy to identify the origins of the relative decline of Scottish industry and labour over the period, critically evaluating the role of the SDA and of government policy in general. Incorporating the impacts of takeover and merger of indigenous companies, the promotion of the branch plant economy, the selective effects of emigration and training schemes, and the reliance on small and medium sized companies to regenerate the economies of city‐regions, an analysis based on the importance of the centre‐periphery relations of monopoly capitalism for the Scottish economy is undertaken. 相似文献
884.
在碱性溶液(pH10.4—11.1)中,钙离子与紫尿酸铵生成橙红色的稳定络合物,在500nm处有最大吸收,钙浓度在2.5—25μg/50ml范围内符合比尔定律,表观摩尔吸光系数为1.2×10~4L·mol~(-1)·cm~(-1),桑德尔灵敏度为0.003μg/cm~2。本法快速、准确、可靠,回收率为94—104%。 相似文献
885.
James Pipkin 《Environmental management》1996,20(6):793-797
While extinctions of individual species are part of a normal cycle, the current rate of extinctions should be a concern to us all. The maintenance of biological diversity is important for utilitarian reasons, quality of life considerations, and because biodiversity is important to sustainable regional economies. Single-species approaches are too limited to protect biodiversity at the landscape, habitat, and watershed levels. New approaches are necessary to deal with the complexity of biological diversity. The administration is using provisions in the Endangered Species Act to bring about broader multispecies habitat protection. The ecosystem approach provides a framework for ensuring that ecological considerations are taken into account, along with economic and social factors, and that all interested parties are able to participate in the decision-making process. 相似文献
886.
Piero Barazzuoli Senatro Izzo Paolo Menicori Massimiliano Micheluccini Massimo Salleolini 《Environmental management》1989,13(5):613-622
The principal aim of this research is to solve problems of water-budget estimation in particularly indeterminate conditions, of the kind that are frequently encountered in the field, in which absence or insufficiency of hydrographic instrumentation prevents the adequate evaluation of runoff.To do this we have developed techniques that are based on the method of Kennessey (1930), in which the runoff coefficient of a watershed in estimated using three physiographic variables (slope angle, permeability, and vegetation cover) and a parameter that defines the climatic conditions of the local area. Our comparison of the Kennessey method with instrumental records from a wide variety of instrumented drainage basins in central Italy shows that the method provides reliable estimates of runoff. Our analysis also indicates the best criteria for its application, as shown by the examples and results presented in this article.This research enables us to present a new application of the method, namely the runoff coefficient map, which, in addition to its specific usefulness for the evaluation of runoff, has three advantages. First, it supplies a more realistic vision of the local distribution of runoff/rainfall ratios; second, it allows one to overcome the spatial constraints imposed by the narrow frame of reference represented by the watershed; and third, it makes an important contribution to the solution of other hydrogeological problems, such as the evaluation of the amount of water required for adequate recharge of the intake areas of deep aquifers or the maintenance of geothermal processes.Hence we propose this mapping technique as a valuable practical aid to regional hydrogeologic planning. 相似文献
887.
Venkata Srinivas Challa Jayakumar Indrcanti Julius M. Baham Chuck Patrick Monika K. Rabarison John H. Young Robert Hughes Shelton J. Swanier Mark G. Hardy Anjaneyulu Yerramilli 《Environmental Fluid Mechanics》2008,8(4):367-387
Mesoscale transport and dispersion of air pollutants from a few major point sources in the Mississippi Gulf coastal region
is calculated using a coupled modeling system consisting of the atmospheric dynamical model WRF and the lagrangian particle
model HYSPLIT. The sensitivity of the dispersion model results to the meteorological fields is studied by conducting an ensemble
of simulations using the WRF model for the same dispersion case. Several parameterization schemes for the physical processes
of boundary layer turbulence and land surface temperature/moisture prediction in WRF are used in various combinations to produce
different meteorological members which are then used for dispersion simulation. The uncertainty in the simulated concentration
probabilities to the meteorological model configurations and the ensemble mean are presented. The parameters used for determining
the uncertainties include the wind fields, temperature, area of concentration and the levels of concentration. The results
indicate that dispersion model results are influenced by the choices made in respect of the planetary boundary layer and land
surface schemes in the mesoscale model to produce the meteorological forecast thereby leading to certain amount of uncertainty
in the resultant concentrations. Results show that the specific choices made about the atmospheric model configuration can
significantly after the simulated concentrations. 相似文献
888.
Assessing coastal vulnerability to climate change: comparing segmentation at global and regional scales 总被引:2,自引:0,他引:2
Silvia Torresan Andrea Critto Matteo Dalla Valle Nick Harvey Antonio Marcomini 《Sustainability Science》2008,3(1):45-65
Recent concerns about potential climate-change effects on coastal systems require the application of vulnerability assessment
tools in order to define suitable adaptation strategies and improve coastal zone management effectiveness. In fact, while
various research efforts were devoted to evaluate coastal vulnerability to climate change on a national to global level, fewer
applications were carried out so far to develop more comprehensive and site-specific vulnerability assessments suitable to
plan possible adaptation measures at the regional scale. In this respect, specific indicators are needed to address climate-change-related
issues for coastal zones and to identify vulnerable areas at the regional level. Two sets of coastal vulnerability indicators
were selected, one for regional and one for global studies, respectively, concerning the same features of coastal systems,
including topography and slope, geomorphological characteristics, presence and distribution of wetlands and vegetation cover,
density of coastal population and number of coastal inhabitants. The proposed set of indicators for the regional scale was
chosen taking into account the availability of environmental and territorial data for the whole coastal area of the Veneto
region and was based on site-specific datasets characterized by a spatial resolution appropriate for a regional analysis.
Moreover, a GIS-based segmentation procedure was applied to divide the coastline into linear segments, homogeneous in terms
of vulnerability to climate change and sea-level rise at the regional scale. This approach allowed to divide the Veneto shoreline
into 140 segments with an average length of about 1 km, while the global scale approach identified four coastal segments with
an average length of about 66 km. The performed comparison indicated how the more detailed approach adopted at the regional
scale is essential to understand and manage the complexities of the specific study area. In fact, the 25-m DEM employed at
the regional scale provided a more accurate differentiation of the coastal area's elevation and thus of coastal susceptibility
to the inundation risks, compared to the 1-km DEM used at the global level. Moreover, at the regional level the use of a 1:20,000
geomorphological map allowed to differentiate the unique landform class detected at the global level (e.g., fluvial plain)
in a variety of more detailed coastal typologies (e.g., open coast eroding sandy shores backed by bedrock) characterized by
a different sensitivity to climate change and sea-level rise. Accordingly, the information provided by regional indicators
can support decision-makers in improving the management of coastal resources by considering the potential impacts of climate
change and in the definition of appropriate actions to reduce inundation risks, to avoid the potential loss of valuable wetlands
and vegetation and to plan the nourishment of sandy beaches subject to erosion processes. 相似文献
889.
Large amounts of waterborne nutrients are major problems for society since they can cause harmful algal blooms in surface water bodies. Consequently, there are a variety of national and international guidelines, e.g. Swedish National Environmental Quality Objectives and the EU Water Framework Directive, which include targets to be achieved within a certain time frame. This paper uses the example of a large Swedish lake to show that national and international targets must be adapted to the local situations. Despite decreasing nutrient concentrations, cyanobacterial blooms in the lake have increased over recent years. We found that these blooms coincide with depleted nitrate–nitrogen concentrations and increased water temperatures. We propose a simple model with water temperature, nitrate–nitrogen and total phosphorus concentrations as input variables as a basis for formulation of regional eutrophication targets. Political decisions should be preceded by open discussion between policymakers and scientists to differentiate between real knowledge, assumptions or feelings. For optimal results, recommendations for reducing nutrient load should consider all sources, including urban stormwater and wastewater from rural houses, and should be founded on a balanced reduction in emissions of algae-available nutrients. In addition, climate change calls for more effective environmental policy to protect surface water resources. 相似文献
890.
What are the processes that shape implementation of multilateral environmental agreements (MEAs) in multilevel governance? In an attempt to address this question, we move from a top-down view of implementation as compliance with international rules to viewing it as a dynamic process shaped by action at various levels. The Ramsar Convention on Wetlands offers an important context to understand the mechanisms that shape multilevel implementation outcomes. We examine Ramsar Convention implementation in Austria, Mexico, and the Republic of Korea in order to identify relevant processes that define multilevel implementation. These cases represent three different types of government, and shed light on the ways in which international law is implemented by respective governments. The Austrian case, a federal government, illustrates the ways in which subnational authorities (the provinces) are influenced by binding regional institutions (EU-rules) to create a more robust context for protection in terms of designation of Ramsar sites. The Mexican case, a semi-federal government, shows how spurred involvement by local NGOs, states, and scientists can result in significant expansion of efforts. The Korean case, a unitary government, demonstrates the ways in which aligning institutional interests (in this case local governments with national ministries) can lead to strong implementation. Analysis of these cases provides two robust findings and one deserving additional study. First, overlapping governance efforts where activity has ties with multiple regional and international biodiversity efforts tend to see cumulative implementation. Second, institutional and organizational complexity can provide opportunities for local actors to drive the implementation agenda through a mix of processes of coordination and contentious politics. A third, more tentative finding, is that multilevel funding sources can ease implementation. 相似文献