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   9627篇
  免费   0篇
废物处理   766篇
环保管理   1208篇
综合类   932篇
基础理论   3103篇
污染及防治   1720篇
评价与监测   1004篇
社会与环境   894篇
  2019年   1篇
  2018年   1473篇
  2017年   1371篇
  2016年   1193篇
  2015年   123篇
  2014年   13篇
  2013年   5篇
  2012年   458篇
  2011年   1337篇
  2010年   688篇
  2009年   597篇
  2008年   876篇
  2007年   1225篇
  2006年   1篇
  2005年   18篇
  2004年   32篇
  2003年   61篇
  2002年   97篇
  2001年   14篇
  2000年   10篇
  1999年   2篇
  1998年   9篇
  1984年   11篇
  1983年   8篇
  1981年   1篇
  1979年   1篇
  1935年   2篇
排序方式: 共有9627条查询结果,搜索用时 12 毫秒
931.
The Arctic is a region of the world experiencing extremely rapid climatic and social change. Indigenous communities have faced similar challenges for millennia and have historically demonstrated remarkable resilience to socioecological perturbations. In contemporary contexts, however, it appears that the pace and extent of change is overwhelming the adaptive capacities of many indigenous communities. Scholars recently completed a survey of living conditions spanning the circumpolar Arctic to quantitatively document the impacts of social and ecological stress across regions. The database they created is called the Survey of Living Conditions in the Arctic or SLiCA. This article explores the utility of using this dataset to compare livelihood systems across three sub-regions of Alaska and four sub-regions within the Chukotka Autonomous Okrug of the Russian Federation. The results point out that livelihood systems in Chukotka have a substantially lower level of sustainability than in Northwest Alaska due to the high prevalence of vulnerable households.  相似文献   
932.
Sub-Saharan Africa has been portrayed as the most vulnerable region to the impacts of global climate change because of its reliance on agriculture which is highly sensitive to weather and climate variables such as temperature, precipitation, and light and extreme events and low capacity for adaptation. This article reviews evidence on the scope and nature of the climate change challenge; and assesses the impact of climate change on agriculture and food security in Sub-Saharan Africa. From the review, it is apparent that the climate in Africa is already exhibiting significant changes, evident by changes in average temperature, change in amount of rainfall and patterns and the prevalence of frequency and intensity of weather extremes. The review also revealed that although uncertainties exist with regards to the magnitude of impacts, climate will negatively affect agricultural production in Sub-Saharan Africa. Specifically, as result of current and expected climate change, the area suitable for agriculture, the length of growing seasons and yield potential, particularly along the margins of semi-arid and arid areas, are expected to decrease. These impacts will affect all components of food security: food availability, food accessibility, food utilisation and food stability and hence increase the risk of hunger in the region. The review thus confirms the general consensus that Sub-Saharan Africa is the most vulnerable region to climate change. It suggests that, policymakers and development agencies should focus on formulating and implementing policies and programmes that promote farm level adaptation strategies currently being practiced by farmers across the region.  相似文献   
933.
Many Indian cities are facing serious problems in managing solid wastes with rise in population and urbanization. This article assesses the existing state of municipal solid waste management (MSWM) in northern India with the aim of identifying the major obstacles to its efficiency and the prospects for improvisation of the solid waste management system in the region. The existing solid waste management system in the region is found to be highly inefficient. Primary and secondary collection, transportation and open dumping are the only activities practiced that too in a non-technical manner. Many cities in region face serious problems in managing solid wastes. The annual waste generation increases in proportion to the rises in population and urbanization. This paper systematically assesses the obstacles in the existing solid waste management system in the urban areas of region and also tries to assess the potentials for its improvisation.  相似文献   
934.
Solid waste management (SWM) in many low- and middle-income countries is sometimes driven by the informal sector. Unfortunately, contributions of the sector to SWM are not acknowledged in many developing countries. This situation often arises from inadequate awareness and lack of advocacy for these development contributions. This article reports on the impact of a study conducted by final-year geography undergraduates on the informal waste management sector in Nsukka urban area, Nigeria. The purposes of this exercise were to stimulate development intervention on behalf of the sector to improve perceptions, attitudes and performance, to impart a range of development research skills and to expose the students to the business opportunities provided by SWM and recycling. Informal waste sector workers and government officials responsible for SWM were interviewed, and some commercial data on recycling operations were collected. Findings of this study indicate that such advocacy initiatives were effective in increasing students’ awareness of opportunities and interest in working in the informal waste sector to promote better SWM and development in Nigeria. Lessons from this university case study are also drawn for other developing countries struggling to achieve the poverty reduction and job creation Millennium Development Goals (MDGs).  相似文献   
935.
Climate is one of the more complex physical systems in nature, its behaviour being fundamentally non-linear and chaotic. In assessing the potential risks from climate change and the costs of averting it, researchers and policymakers encounter pervasive uncertainty. Sceptics demand to get rid of the inherent uncertainties, and some experts, on the other end, keep sending out messages of catastrophic scenarios hoping that this will increase people’s awareness of the danger we face. The recent admission of a mistake in IPCC’s Climate change 2007 report (promptly broadcast by all the major media groups and newspapers from Jan. 20th 2010 onwards) made by the head of the Intergovernmental Panel on Climate Change—that Himalayan glaciers could melt away by 2035 (the IPCC claim of 2035 is wrong by over 300 years.)—has already brought a damage to the IPCC’s reputation that is likely to be considerable. But in this paper, perhaps risking being provocative and paradoxical, instead of looking for the right answers to what we think are inevitable uncertainties, we intend to search for new questions that may lead to a new way of thinking and may bring about new lifestyles and behaviour for citizens and firms.  相似文献   
936.
Coastal zones provide habitat cores and corridors that maintain the diversity of entire landscapes, and they can form the cornerstone elements of regional conservation strategies. Natural environmental driving factors and excessive anthropogenic activities play important roles in coastal wetland change. Many studies have used remote sensing images to map and assess coastal wetland change on local or regional scales. This paper aims to provide insight into coastal wetland change in the Yancheng National Nature Reserve (YNNR) using remote sensing technology and landscape metrics analysis. The results reveal that grass flat and reed areas have significantly decreased, whereas agriculture fields, aquaculture ponds and built-up areas have continuously increased from 1988 to 2006. The spatial pattern of the coastal landscape has become fragmented and heterogeneous under great pressure from rapid economic development and population growth. The wetland changes have important impacts on natural habitat of the red-crowned cranes. The results of this study provide basic information that is required for developing measures toward a sustainable management and conservation of the YNNR.  相似文献   
937.
Anthropogenic biomass burning in insular Southeast Asia facilitates conversion and degradation of ecosystems and emits high amounts of carbon into the atmosphere. We analyzed the influence of peat soil and land cover distribution on the occurrence and characteristics of vegetation fires. Two years of satellite-based active fire detections over Peninsular Malaysia, Sumatra, Borneo and Java were examined together with land cover and peatland maps. Our results showed that fire occurrence nearly tripled (23,000 → 68,000) from a wet La Niña year (2008) to a drier El Niño year (2009). In both years, fires were concentrated in peatlands (in 2009 41% of fires vs. 10% of land area), and the majority of large-scale burning took place in peatlands. Variation in peatland land cover within the study area was noticed to create remarkable different fire regimes. Biomass burning in the intensely managed Sumatran peatlands was characterized by large-scale land clearance fires that took place annually to varying extent. The largely unmanaged degraded peatland ecosystems of Borneo, on the other hand, experienced very little fire activity in a wet year but were ravaged by large-scale wildfires when El Niño conditions arose. We conclude that fire regime characteristics in insular Southeast Asia are strongly connected to occurrence of peat soil and land management status. This leads to high variation of fire activity within this region both annually (depending on weather patters) and over longer time range (depending on land cover/management issues) and greatly complicates estimation of the effects of fires.  相似文献   
938.
A regional climate change impact assessment was conducted which investigated the timing of the first appearance of furunculosis caused by the bacterium, Aeromonas salmonicida, in fish of the Ouje-Bougoumou region of northern Quebec, Canada. Historical data were used to assess whether there was a temporal relationship between increased temperatures (observed climate data) and the appearance of furunculosis (traditional environmental knowledge was used to provide context). To project future impacts of climate change, climate models and lake models were used. Regression analysis revealed a significant, positive temporal trend in mean air temperature. The temperature range conducive to A. salmoncida survival coincided with the first appearance of furunculosis. In addition, it is predicted that lake temperatures will remain suitable for the presence of A. salmonicida into the future; it is likely that the disease will persist throughout the twenty-first century. Climate change appears to be a factor explaining the onset of furunculosis; however, other factors/stressors cannot be discounted, such as, the effects past mining activities near the lakes of the Ouje-Bougoumou region have had on the body burden of contaminants in the fish (and the potential effects on the fish immune system).  相似文献   
939.
Rapid land-use change arising from incentives for afforestation has created tensions in rural communities previously dominated by agricultural enterprises. This paper reports on an innovative experiment with social learning that incorporated participatory modelling to resolve community concerns in a case study of plantation forestry in the Upper Clarence catchment of north-eastern NSW Australia. The development of a diagnostic framework helped identify socioeconomic and environmental issues within the community for investigation by a self-selected participatory advisory committee (PAC) representing a diversity of views. Implementation of a social learning exercise offered empathetic and intellectual engagement among PAC members that maintained interest, built confidence, and improved problem-solving capacity while fostering group ownership over decision making. A shared understanding of dynamic landscape problems helped empower participants to collaboratively develop solutions for improved management and operational practices, and cooperate to explore further options for plantation industry development under existing policy guidelines which are presented in this paper. As a result of frank discussions between diverse stakeholders in a mutually respectful learning environment that combined local, scientific and expert knowledge, concerns dissipated and participants developed a more favourable view of plantation forestry activity.  相似文献   
940.
Using the focusing event framework, a comprehensive analysis of private households’ and businesses’ preparedness was undertaken in the aftermath of the 2002 and 2006 flood events on the Elbe River in Germany. In August 2002, preparedness of households (n = 235) and businesses (n = 103) was low: 30% of the households and 54% of the businesses took no precautionary measures before the flood event. Many undertaken emergency measures were ineffective, since only 26% of all households knew how to react when the flood warning came, and only 9% of businesses had an emergency plan in place. Due to this extreme flood, double-loop learning occurred in many households and businesses, so that many did implement precautionary measures. The distribution of adopted precautionary measures for households fits well to Preisendörfer’s low-cost hypothesis, but does not apply for businesses. Only 10% of the households (n = 112), but still 29% of the businesses (n = 41) were unprepared before the flood in 2006. Significant improvement in flood preparedness activities is still necessary. Particularly for businesses, regulatory programs and programs encouraging proactive behaviour should be implemented. The focusing event framework proofed to be a useful tool for a differentiated analysis of the responses to and learning due to a disaster also in the commercial and private sector.  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