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691.
692.
Reactive properties of aquifer solid phase materials play an important role in solute fate and transport in the natural subsurface on time scales ranging from years in contaminant remediation to millennia in dynamics of aqueous geochemistry. Quantitative tools for dealing with the impact of natural heterogeneity in solid phase reactivity on solute fate and transport are limited. Here we describe the use of a structural variable to keep track of solute flux exposure to reactive surfaces. With this approach, we develop a non-reactive tracer model that is useful for determining the signature of multi-scale reactive solid heterogeneity in terms of solute flux distributions at the field scale, given realizations of three-dimensional reactive site density fields. First, a governing Eulerian equation for the non-reactive tracer model is determined by an upscaling technique in which it is found that the exposure time of solution to reactive surface areas evolves via both a macroscopic velocity and a macroscopic dispersion in the artificial dimension of exposure time. Second, we focus on the Lagrangian approach in the context of a streamtube ensemble and demonstrate the use of the distribution of solute flux over the exposure time dimension in modeling two-dimensional transport of a solute undergoing simplified linear reversible reactions, in hypothetical conditions following prior laboratory experiments. The distribution of solute flux over exposure time in a given case is a signature of the impact of heterogeneous aquifer reactivity coupled with a particular physical heterogeneity, boundary conditions, and hydraulic gradient. Rigorous application of this approach in a simulation sense is limited here to linear kinetically controlled reactions. 相似文献
693.
- DOI: http://dx.doi.org/10.1065/espr2006.02.294
Background, Aim and Scope. To better address the requirements of the changing multilateral order, the United Nations Industrial
Development Organization (UNIDO) Cleaner Production Programme, in 2004, developed the new Sustainable Industrial Resource
Management (SIRM) approach. This approach is in accordance with the principles decided at the United Nations Conference on
Environment and Development (UNCED) in Rio de Janeiro, Brazil in 1992. Unlike the traditional approaches to environmental
management, the SIRM concept captures the idea of achieving sustainable industrial development through the implementation
of circular material and energy flows in the entire production chain and reduction of the amount of material and energy used
with greater efficiency solutions. The SIRM approach seeks to develop new models to encourage a shift from selling products
to supplying services, modifying, in this manner, the supplier/user relationship and resulting in a win-win situation for
the economy and the environment. Chemical Leasing represents such a new service-oriented business model and is currently being
promoted by UNIDO′s Cleaner Production Programme.
Main Features. One of the potential approaches to address the problems related to ineffective use and over-consumption of
chemicals is the development and implementation of Chemical Leasing business models. These provide concrete solutions to the
effective management of chemicals and on the ways negative releases to the environment can be reduced. The Chemical Leasing
approach is a strategy that addresses the obligations of the changing international chemicals policy by focusing on a more
service-oriented strategy. Mexico is one of the countries that were selected for the implementation of UNIDO's demonstration
project to promote Chemical Leasing models in the country. The target sector of this project is the chemical industry, which
is expected to shift their traditional business concept towards a more service and value-added approach. This is being achieved
through the development of company specific business models that implement the above-indicated Chemical Leasing concept with
the support from the Mexican National Cleaner Production Centre (NCPC).
Results and Conclusions. The implementation of Chemical Leasing in Mexico has proven to be an efficient instrument in enhancing
sustainable chemical management and significantly reducing emissions in Mexico. Several companies from the chemical industrial
sector implement or agreed to implement chemical leasing business models. Based on the positive findings of the project,
several Mexican companies started to negotiate contents of possible Chemical Leasing contracts with suitable business partners.
The project further aimed at disseminating information on Chemical Leasing. It successfully attracted globally operating companies
in the chemicals sector to explore possibilities to implement Chemical Leasing business models in Mexico. At the international
level, the results of the UNIDO project were presented on 20TH September 2005 during a side event of the Strategic Approach
to International Chemicals Management (SAICM) Preparation Conference in Vienna.
Recommendations and Outlook. To facilitate the promotion and application of Chemical Leasing project at international level,
UNIDO is currently developing a number of tools to standardize Chemical Leasing projects. These include, among others, Chemical
leasing contract models; Chemical Leasing data base to find partners for chemical leasing; and guidelines to implement Chemical
Leasing projects and work programmes. 相似文献
694.
王顺克 《长江流域资源与环境》2002,(3)
由于自然尤其是人为因素的影响 ,三峡库区生态环境遭受严重破坏 ,农民增收缺少支撑 ,加上三峡工程的修建 ,淹没了大批肥田沃土 ,更加激化了人地矛盾 ,导致该地区生态环境恶化、生态承载容量减少、经济贫困化恶性循环 ,最终致使生态环境保护和经济发展严重对立。要从根本上解决库区生态环境与经济的协调发展问题 ,关键在于发展生态经济。从三峡库区以山地、丘陵为主的地形特征及其分布特点和气候、土壤条件以及资源特色出发 ,根据生态学、生态经济学的基本原理要求 ,提出了建立由水域生态经济产业带、沿江经济支撑产业带、腹地生态农业带、高山垂直绿色产业带构成的生态经济复合产业带的构想 ,其中每个产业带又由若干关联性强的产业有机复合而成。还提出了发展三峡库区生态经济的具体政策建议和措施。 相似文献
695.
696.
Trends of changes in the successional status of northern taiga forests exposed to technogenic pollution in the Kola Peninsula are discussed. Main studies of digression in spruce and pine forests are characterized on the basis of the dynamics of species composition of phytocenoses and chemical composition of atmospheric fallout, soils, and dominant plants. 相似文献
697.
方明钦 《再生资源与循环经济》2012,5(10):25-28
对建设福州市海峡供销再生资源产业园区项目的背景、内容、规模,以及园区开发经营和效益进行可行性分析研究。园区建设作为一个长期项目,将成为海峡西岸经济区重要的废旧商品回收利用示范基地。 相似文献
698.
Extensive green areas generate a recognizable green identity of Ljubljana. Due to the challenges of climate change and urbanization the city's spatial policy highlights revitalization of degraded urban areas, preserving the quality and scope of the existing green network and the protection of multifunctional natural areas surrounding the city. Article describes the project of Rakova Jelša Park as a good example of these policies. With an NGO initiative a former degraded area with illegal dumping and non-indigenous vegetation was transformed into recreational park with increased biocultural diversity. Important lesson of the project is that opening up space for public use not only prevents degradation, but also improves the quality of urban ecosystems. One of the challenges for the city's future sustainable ecosystem development will be a more active cooperation with its citizens in the green infrastructure policy and later also a partial transfer of responsibility for green areas to them. 相似文献
699.
针对2004—2016年中国地级市工业生态效率与PM2.5的时空关联特征和影响作用关系的研究表明:(1)工业生态效率与PM2.5呈时空交错分布特征,PM2.5高污染区连片分布于华北平原及长江中下游城市,工业生态效率高等级区集中分布于长三角、珠三角和环渤海经济区等沿海地市及中西部城市群内部分中心地市;(2)工业生态效率对PM2.5的冲击表现出“U型”变化的负向累积效应,PM2.5对工业生态效率的冲击则表现为“倒U型”变化的正向累积效应;(3)工业生态效率与PM2.5呈稳定时空关联演化特征,高高关联类型区集中分布于京津冀城市群、山东半岛城市群和长三角城市群内大部分城市,低低关联类型区多分布于鄱阳湖城市群、关中城市群及西部地市;(4)工业生态效率对PM2.5总体上具有显著且稳健的正向影响,但表现出明显的空间异质性,工业集聚水平、科技创新及城市绿化率起到显著负向影响,而城市规模、环保监督及产业结构系数影响并不显著。 相似文献
700.
Julia Ohl Alexander Wezel Glenn H. Shepard Jr. Douglas W. Yu 《Environment, Development and Sustainability》2008,10(6):827-843
In this study, we investigate whether traditional swidden agriculture on nutrient-poor tropical soils can sustainably support
a growing indigenous population within Manu National Park, Peru. Based on interviews with 50 Matsigenka farmers, as well as
GPS mapping and field visits, we established the location and size of all 124 swidden gardens cultivated in 2000 and 2001.
Using a GIS-based soil map of Manu Park, we identify the total extent of potential arable land (1) throughout the park zones
currently available for Matsigenka habitation, and (2) within the vicinity of the two study communities. Taking into account
current per capita garden size, cultivation and fallow practices, we calculate the maximum human carrying capacity of swidden
agriculture for (1) all available park zones and (2) the immediate vicinity of the two current communities. Even given the
second, highly limited scenario, the sustainable human carrying capacity is estimated to be 2,138 individuals, which is far
higher than the current population of about 420 people. Thus, arable land does not appear to be a limiting factor for the
growth of the indigenous population in Manu Park at the current time. Other possible limiting factors for population growth
are identified and discussed. We conclude that a conservation policy of population stabilization around the current settlements
is viable in that it will not result in reduced resource availability over the next few decades, and that the challenge is
to identify and mitigate the forces causing population fissioning and spread.
Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献