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821.
人工湿地在污水处理中的应用及其展望 总被引:15,自引:0,他引:15
作为污水处理的有效途径,人工湿地具有众多的优点。分析了人工湿地的构造及去污机理,总结了人工湿地在污水处理中应用的历史及现状,并对其未来的应用前景做出了展望。 相似文献
822.
森林采伐更新效益综合评价的几个基本问题 总被引:1,自引:0,他引:1
本文主要探讨以用材林为主的森林采伐更新效益综合评价的几个基本问题。论述了采伐更新的特点,提出了综合评价的三个主要方面,四条基本原则以及基本方法与指标体系。最后对采伐更新的生产效益、生态与社会效益评价的具体方法进行了探讨。 相似文献
823.
Richard S.J. Tol 《Environmental Modeling and Assessment》1997,2(3):151-163
This paper presents the Climate Framework for Uncertainty, Negotiation and Distribution (FUND), an integrated assessment model
of climate change, and discusses selected results. FUND is a nine‐region model of the world economy and its interactions with
climate, running in time steps of one year from 1990 to 2200. The model consists of scenarios for economy and population,
which are perturbed by climate change and greenhouse gas emission reduction policy. Each region optimizes its net present
welfare. Policy variables are energy and carbon efficiency improvement, and sequestering carbon dioxide in forests. It is
found that reducing conventional air pollution is a major reason to abate carbon dioxide emissions. Climate change is an additional
reason to abate emissions. Reducing and changing energy use is preferred as an option over sequestering carbon. Under non‐cooperation,
free riding as well as assurance behaviour is observed in the model. The scope for joint implementation is limited. Under
cooperation, optimal emission abatement is (slightly) higher than under non‐cooperation, but the global coalition is not self‐enforcing
while side payments are insufficient. Optimal emission control under non‐cooperation is less than currently discussed under
the Framework Convention on Climate Change, but higher than observed in practice.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
824.
C. Cosmi V. Cuomo M. Macchiato L. Mangiamele S. Masi M. Salvia 《Environmental Modeling and Assessment》2000,5(1):19-27
Air pollution is one of the most pressing environmental problems which affects likewise urban, industrial and rural areas.
Environmental planners, regulators and decision makers need reliable, scientifically based tools to find out strategies for
controlling air pollution in a cost-effective way, taking into account the whole productive system. In this framework the
basic elements of energy-environmental planning have to be extended to include also waste processing technologies amongst
the usually considered pollution sources. Bottom-up optimizing models, based on linear programming techniques and customized
for specific cases, represent a powerful tool in energy-environmental management. This paper focuses on the integrated modeling
of material flows and energy system performed on a local scale case study (Basilicata Region, Southern Italy) using the linear
programming model IEA-MARKAL. We have evaluated the feasibility of the model in representing the waste management system to
estimate the environmental impact of the waste processing technologies in the context of the whole productive system. A sensitivity
analysis has been carried out to emphasize the connections between tariffs, waste disposal technologies assessment and atmospheric
emissions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
825.
Monitoring the Hydrology of Canadian Prairie Wetlands to Detect the Effects of Climate Change and Land Use Changes 总被引:3,自引:0,他引:3
There are millions of small isolatedwetlands in the semi-arid Canadian prairies. These`sloughs' are refuges for wildlife in an area that isotherwise intensively used for agriculture. They areparticularly important as waterfowl habitat, with morethan half of all North American ducks nesting inprairie sloughs. The water levels and ecology of thewetlands are sensitive to atmospheric change and tochanges of agricultural practices in the surroundingfields. Monitoring of the hydrological conditions ofthe wetlands across the region is vital for detectinglong-term trends and for studying the processes thatcontrol the water balance of the wetlands. Suchmonitoring therefore requires extensive regional-scaledata complemented by intensive measurements at a fewlocations. At present, wetlands are being enumeratedacross the region once each year and year-roundmonitoring is being carried out at a few locations. Theregional-scale data can be statistically related toregional climate data, but such analyses cast littlelight on the hydrological processes and have limitedpredictive value when climate and land use arechanging. The intensive monitoring network has providedimportant insights but it now needs to be expanded andrevised to meet new questions concerning the effects ofclimate change and land use. 相似文献
826.
Robert J. Imeson Jeroen C.J.M. Van Den Bergh Jeljer Hoekstra 《Environmental Modeling and Assessment》2002,7(4):259-271
An overview of the structure and elements of integrated models aimed at studying fishery management policies using static and dynamic optimisation techniques is presented. Continuous and discrete time models are considered under both open-access and sole-owner settings. A variety of economic and biological processes that affect the fishery as a whole is examined. It turns out that overseeing important fish population characteristics such as metapopulation dynamics and multi-species interaction can lead to serious misrepresentation of the fishery and suboptimal controls. Adequate understanding of the economic conditions and considerations potentially affecting the fishermen is necessary to model their behaviour and address their concerns. Misrepresentation of these economic and biologic processes will have an impact on the success of management policies in attaining a sustainable fish population. 相似文献
827.
Social consequences associated with the use of various optimization methods in the protection of air quality 总被引:1,自引:0,他引:1
Jacek Żeliński Jolanta Telenga-Kopyczyńska 《Journal of Environmental Planning and Management》2019,62(6):960-978
The fundamental tactics employed by the EU against air contamination, which are intended to maintain concentrations at a level that does not exceed the permissible values, usually entail considerable expense. To reduce this to a minimum, the procedure of economic optimization of air quality can be applied. When performed for a heavily polluted industrial city, it shows that it is possible to maintain concentrations below the threshold of air quality standards with relatively moderate expenditure. These evaluations also reveal that variations in population density distribution call into question the conventional wisdom that uniform air quality standards provide the best protection against air contamination for a whole region. On the contrary, an optimization that forces a drop in concentration to be evenly spread over the population, without reference to air quality standards, may lead to more efficient protection of human health and make no difference to overall expenditure. 相似文献
828.
Mediterranean wetlands are of key interest in the preservation of biodiversity. However, their ecological water requirement is in constant competition with human uses, particularly in a context of aridity and climate change. This paper examines the case of the Ichkeul Lake‐Lagoon system located in the north of Tunisia in a river basin that is heavily contributing to the water supply of southern regions through water transfers. It maps out the various actors involved, their stakes, discourses and strategies, and explains the current degradation of the Ichkeul system by unpacking the decision‐making power of these actors. It confirms that marginal social groups, ecosystems and next generations are the main parties affected by current water allocation patterns. 相似文献
829.
为筛选出性能更好的人工湿地填料,采用等温吸附-解吸试验,测定了29种天然和非天然人工湿地填料的孔隙率、渗透系数及其对NH3-N的吸附-解吸特性. 结果表明:锯末、瓷砖、鸡蛋壳、瓷砂陶粒、火山岩等材料的孔隙率较大,瓷砂陶粒、海绵铁、石灰石、页岩陶粒、砾石等材料的渗透系数较大;Freundlich和Langmuir等温吸附方程能较好地拟合各填料对NH3-N的吸附特征,通过Langmuir等温吸附方程计算,对NH3-N的理论饱和吸附量居前5位的填料依次是火山岩(1.700 0 mg/g)、瓷砂陶粒(1.620 0 mg/g)、生物炭(1.353 0 mg/g)、沸石(1.350 0 mg/g)、石榴石(1.190 0 mg/g). 吸附速率的变化与填料吸附NH3-N的途径密切相关. 吸附饱和的生物炭、焦炭、大理黏土、沸石、磁铁矿、石英砂主要通过离子交换作用吸附NH3-N,稳定性好,解吸率均小于20%;瓷砂陶粒和火山岩对NH3-N的解吸率分别为24.50%和35.51%,既有物理吸附也有离子交换作用. 火山岩、瓷砂陶粒、生物炭、沸石对较高浓度NH3-N的吸附效果较好. 研究显示,火山岩、生物炭、瓷砂陶粒、沸石等适合作为人工湿地中吸附NH3-N的填料. 相似文献
830.