首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   45篇
  免费   1篇
安全科学   1篇
废物处理   2篇
环保管理   18篇
综合类   10篇
基础理论   6篇
污染及防治   2篇
社会与环境   2篇
灾害及防治   5篇
  2019年   1篇
  2016年   1篇
  2014年   3篇
  2013年   1篇
  2012年   2篇
  2009年   1篇
  2008年   2篇
  2007年   6篇
  2006年   1篇
  2005年   2篇
  2004年   3篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  1999年   3篇
  1998年   3篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   2篇
  1988年   1篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
排序方式: 共有46条查询结果,搜索用时 62 毫秒
31.
Climate change incurs costs, but government adaptation budgets are limited. Beyond a certain point, individuals must bear the costs or adapt to new circumstances, creating political-economic tipping points that we explore in three examples. First, many Alaska Native villages are threatened by erosion, but relocation is expensive. To date, critically threatened villages have not yet been relocated, suggesting that we may already have reached a political-economic tipping point. Second, forest fires shape landscape and ecological characteristics in interior Alaska. Climate-driven changes in fire regime require increased fire-fighting resources to maintain current patterns of vegetation and land use, but these resources appear to be less and less available, indicating an approaching tipping point. Third, rapid sea level rise, for example from accelerated melting of the Greenland ice sheet, will create a choice between protection and abandonment for coastal regions throughout the world, a potential global tipping point comparable to those now faced by Arctic communities. The examples illustrate the basic idea that if costs of response increase more quickly than available resources, then society has fewer and fewer options as time passes.  相似文献   
32.
The concept of value is central to mineral economics as it is all branches of economics. In the minerals sphere particular problems are posed for a theory of value by, firstly, the non- renewability of mineral resources, secondly the substantial effort that must be made to convert a mineral into a useful product, and finally the perception of minerals, both economically and symbolically, as peculiarly national forms of wealth. Some thoughts are offered on different approaches to mineral resource valuation and on the frequently conflicting principles of exploitation to which these various approaches give rise.  相似文献   
33.
分析环境问题产生的经济机制及环境与经济的相互关系,阐述可持续发展理论的含义和主要特征,提出从可持续发展出发国民经济核算体系、资源与产品价格价系、项目评价方法及经济制度等方面应作出调整。  相似文献   
34.
After energy, water is the most critical commodity to be made available to people to keep them alive. Saudi Arabia has vast land and people are living in all regions. Most of these are connected to national grid but some are not, especially in remote areas like in the north, south, and west south. Pumping water in remote areas for domestic needs like agriculture and animals beside human needs is essential and require regular power supply. The present idea of wind-PV-Battery hybrid power system based on 100% renewable source is being proposed to utilize and tested in some of the regions on experimental bases. Of the five locations chosen for the purpose, namely Dhahran, Riyadh, Jeddah, Guriat and Nejran, some are good from both wind and solar intensity point of view some have good winds only and some good solar only. Nearly optimal size of PV-Wind water pumping system is determined for each of these sites considering the availability of solar and wind energy distributions throughout the year in these sites. It is shown that the monthly total water pumping capacity when using nearly optimal PV-Wind water pumping system is fairly uniform throughout the year except for the sites of Guriat and Riyadh. In these sites higher water pumping capacity is observed during the spring and summer months. On the other hand the cost of underground water pumping is found to vary between 6 to 12 US¢/m3 for the five sites considered.  相似文献   
35.
A number of scavenger species have suffered population declines across Europe. In attempts to reverse their decline, some land and wildlife managers have adopted the practice of leaving or placing out carcasses of wild or domestic herbivores to provide a source of carrion. However, this can be a controversial practice, with as yet unclear outcomes for many target species and the ecosystems they are part of. Here we bring out the key aspects of this increasingly common conservation practice illustrated using three contrasting cases studies. We show that the provision of carcasses is often motivated by a desire to benefit charismatic species or to facilitate nutrient cycling throughout an ecosystem. Evidence for the effectiveness of this practice in achieving these objectives, however, is mostly lacking, with ecologists studying “easier” species groups such as beetles and therefore not providing relevant insights. Moreover, conflicts between environmental policies that carcass provisioning is aimed at and other social and economic objectives do occur but these projects are often designed without taking into account this broader context. We conclude that expecting carcasses to simply be “good for biodiversity” may be too naïve a view. A greater knowledge of the impact of carcass provisioning and placement on ecosystems and society at large is required before it can become a more effective conservation tool at a wider scale.  相似文献   
36.
37.
西方灾害经济学研究的历史回顾   总被引:3,自引:3,他引:3  
张显东  梅广清 《灾害学》1998,13(4):81-87
对西方灾害经济学发展的历史作了简要的叙述,对其关心的主要问题作了初步的归纳,并按灾害对经济系统物质方面和制度方面的影响分别对百方灾害经济学研究的历史文献作了综述和评论.  相似文献   
38.
This article provides an overview of the use of risk-based analysis (RBA) in flood damage assessment, and it illustrates the use of Geographic Information Systems (GIS) in identifying flood-prone areas, which can aid in flood-mitigation planning assistance. We use RBA to calculate expected annual flood damages in an urban watershed in the state of Rhode Island, USA. The method accounts for the uncertainty in the three primary relationships used in computing flood damage: (1) the probability that a given flood will produce a given amount of floodwater, (2) the probability that a given amount of floodwater will reach a certain stage or height, and (3) the probability that a certain stage of floodwater will produce a given amount of damage. A greater than 50% increase in expected annual flood damage is estimated for the future if previous development patterns continue and flood-mitigation measures are not taken. GIS is then used to create a map that shows where and how often floods might occur in the future, which can help (1) identify priority areas for flood-mitigation planning assistance and (2) disseminate information to public officials and other decision-makers.  相似文献   
39.
The greenhouse gas (GHG) emissions from MSW landfill, and control methods to eliminate or minimize these impacts including energy recovery from landfill gas (LFG) of MSW landfill in Thailand have been evaluated. Life Cycle Assessment (LCA) is used as the analytical tool to evaluate the environmental consequences of landfilling holistically. The economic implications of the control methods are also briefly assessed. The results show that in terms of GHG emissions as well as in terms of economics, it is more advantageous to have a large centralized landfill and produce electricity from the LFG rather than having several small, localized landfills despite significantly lower transportation requirement for the latter case. Sensitivity analysis revealed that the global warming potential was sensitive to gas collection efficiency as well as methane oxidation rate in the landfill. This study shows the utility of a life cycle approach for evaluating LFG-to-energy (LFGTE) projects.  相似文献   
40.
Fires have attracted interest and generated alarm since the early 1980s. This concern has been particularly evident in tropical forests of Southeast Asia and the Amazon, but disastrous fires in recent summers in Australia, Europe, and the United States have drawn worldwide attention. Concern about forest fires, and related air pollution and biodiversity impacts, led international organisations and northern countries – such as the Asian Development Bank, the European Union, the Food and Agriculture Organisation, the United Nations Environment Programme, the World Bank, and the government of Germany – to undertake fire assessments and provide technical assistance. Nongovernmental organisations, such as the International Union for Conservation of Nature and Natural Resources and World Wide Fund for Nature, have also devoted increased attention to fires. Aiming at prevention of future fires, 40 fire projects and missions costing well over US$30 million have worked in Indonesia over the last 20 years. Despite the money and effort spent on them, fires continue to burn every year. It may appear to some that efforts to address the ‘fire problem’ have not been effective as fires still occur. There remains a lack of clarity about ‘fire problems’, which has, at times, led to the adoption of policies that may have negative impacts on livelihoods, the environment, and the economy. Two ‘simple’ changes in the way fires are considered would significantly improve fire-related policies and initiatives.
•  Fires should be seen as a component of land management processes, rather than as a ‘problem’ to be prevented, suppressed, or mitigated.
•  Not all fires are the same.
These two points are discussed in the context of Southeast Asia, and particularly Indonesia, as an example of the problems and questions faced by tropical countries. We argue that efforts on fires so far have generated increased knowledge of the ’fire problem’; now, we need to capitalize on that knowledge to avoid wasting money in the future.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号