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   98篇
  免费   5篇
  国内免费   3篇
安全科学   4篇
废物处理   6篇
环保管理   34篇
综合类   8篇
基础理论   21篇
环境理论   1篇
污染及防治   18篇
评价与监测   10篇
社会与环境   3篇
灾害及防治   1篇
  2022年   4篇
  2021年   5篇
  2020年   1篇
  2019年   3篇
  2018年   2篇
  2017年   2篇
  2016年   9篇
  2015年   3篇
  2014年   3篇
  2013年   9篇
  2012年   5篇
  2011年   6篇
  2010年   5篇
  2009年   5篇
  2008年   7篇
  2007年   4篇
  2006年   3篇
  2005年   11篇
  2004年   4篇
  2003年   2篇
  2002年   3篇
  2001年   2篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1992年   1篇
  1989年   1篇
排序方式: 共有106条查询结果,搜索用时 0 毫秒
1.
In accordance with the Disaster Mitigation Act, most US counties have a hazard mitigation plan (HMP) to reduce future disaster losses. HMPs are important as they can be used to proactively assess risk, direct future development, raise awareness and build consensus. Using a population-based sample, we interviewed residents of Bertie County, NC, about their awareness of and participation in the HMP process to determine if demographics, social vulnerability or hazard vulnerability were associated with increased awareness or participation. We also assessed whether these factors were associated with knowledge of policy changes and investments that were adopted in the HMP. Overall, the unemployed were the only group less likely to report awareness of or participation in HMP development. African-Americans, mobile home residents, the poor, short-term residents and those with less disaster experience were less likely to be aware of policies and investments prioritised in the HMP. Targeted efforts to increase awareness could potentially improve disaster outcomes among vulnerable populations.  相似文献   
2.
Providing an accurate estimate of the dry component of N deposition to low N background, semi-natural habitats, such as bogs and upland moors dominated by Calluna vulgaris is difficult, but essential to relate nitrogen deposition to effects in these communities. To quantify the effects of NH3 inputs to moorland vegetation growing on a bog at a field scale, a field release NH3 fumigation system was established at Whim Moss (Scottish Borders) in 2002. Gaseous NH3 from a line source was released along of a 60 m transect, when meteorological conditions (wind speed >2.5 m s?1 and wind direction in the sector 180–215°) were met, thereby providing a profile of decreasing NH3 concentration with distance from the source. In a complementary study, using a NH3 flux chamber system, the relationships between NH3 concentrations and cuticular resistances were quantified for a range of NH3 concentrations and micrometeorological conditions for moorland vegetation. Cuticular resistances increased with NH3 concentration from 11 s m?1 at 3.0 μg m?3 to 30 s m?1 at 30 μg m?3. The NH3 concentration data and the concentration-dependent canopy resistance are used to calculate NH3 deposition taking into account leaf surface wetness. The implications of using an NH3 concentration-dependent cuticular resistance and the importance for refining critical loads are discussed.  相似文献   
3.
Elemental concentrations and bioaccessibility were determined in background soils collected in Canada as part of the North American Geochemical Landscapes Project. The concentrations of As, Cr, Cu, Co, Ni and Zn were higher in the C-horizon (parent material) compared to 0–5 cm (surface soil), and this observation along with the regional distribution suggested that most of the variability in concentrations of these elements were governed by the bedrock characteristics. Unlike the above-stated elements, Pb and Cd concentrations were higher in the surface layer reflecting the potential effects of anthropogenic deposition. Elemental bioaccessibility was variable decreasing in the order Cd > Pb > Cu > Zn > Ni > Co > As > Cr for the surface soils. With the exception of As, bioaccessibility was generally higher in the C-horizon soils compared to the 0–5 cm soils. The differences in metal bioaccessibility between the 0–5 cm and the C-horizon and among the provinces may reflect geological processes and speciation. The mean, median or 95th percentile bioaccessibility for As, Cr, Cu, Co, Ni and Pb were all below 100 %, suggesting that the use of site-specific bioaccessibility results for these elements will yield more accurate estimation of the risk associated with oral bioavailability for sites where soil ingestion is the major contributor of human health risk.  相似文献   
4.
The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive-bred individuals were released into free-living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to 400–480 individuals, and the species was twice downlisted on the International Union for the Conservation of Nature (IUCN) Red List. We analyzed the impacts of the bottleneck and genetic rescue on neutral genetic variation during and after population recovery (1993–2008) with restriction site-associated sequencing, microsatellite analyses, and quantitative genetic analysis of studbook data of 1112 birds from zoos in Europe and the United States. We used computer simulations to study the predicted changes in genetic variation and population viability from the past into the future. Genetic variation declined rapidly, despite the population rebound, and the effective population size was approximately an order of magnitude smaller than census size. The species carried a high genetic load of circa 15 lethal equivalents for longevity. Our computer simulations predicted continued inbreeding will likely result in increased expression of deleterious mutations (i.e., a high realized load) and severe inbreeding depression. Without continued conservation actions, it is likely that the pink pigeon will go extinct in the wild within 100 years. Conservation rescue of the pink pigeon has been instrumental in the recovery of the free-living population. However, further genetic rescue with captive-bred birds from zoos is required to recover lost variation, reduce expression of harmful deleterious variation, and prevent extinction. The use of genomics and modeling data can inform IUCN assessments of the viability and extinction risk of species, and it helps in assessments of the conservation dependency of populations.  相似文献   
5.
Ten ways remote sensing can contribute to conservation   总被引:1,自引:0,他引:1       下载免费PDF全文
In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners’ use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain‐referral survey. We then used a workshop‐based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real‐time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing‐derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to monitor and evaluate the effectiveness of conservation efforts? How does the expansion and intensification of agriculture and aquaculture alter ecosystems and the services they provide? How can remote sensing be used to determine the degree to which ecosystems are being disturbed or degraded and the effects of these changes on species and ecosystem functions?  相似文献   
6.
Angradi, Ted R., David W. Bolgrien, Matt A. Starry, and Brian H. Hill, 2012. Modeled Summer Background Concentration of Nutrients and Suspended Sediment in the Mid‐Continent (USA) Great Rivers. Journal of the American Water Resources Association (JAWRA) 48(5): 1054‐1070. DOI: 10.1111/j.1752‐1688.2012.00669.x Abstract: We used regression models to predict summer background concentration of total nitrogen (N), total phosphorus (P), and total suspended solids (TSS), in the mid‐continent great rivers: the Upper Mississippi, the Lower Missouri, and the Ohio. From multiple linear regressions of water quality indicators with land use and other stressor variables, we determined the concentration of the indicators when the predictor variables were all set to zero — the y‐intercept. Except for total P on the Upper Mississippi River, we could predict background concentration using regression models. Predicted background concentration of total N was about the same on the Upper Mississippi and Lower Missouri Rivers (430 μg l?1), which was lower than percentile‐based values, but was similar to concentrations derived from the response of sestonic chlorophyll a to great river total N concentration. Background concentration of total P on the Lower Missouri (65 μg l?1) was also lower than published and percentile‐based concentrations. Background TSS concentration was higher on the Lower Missouri (40 mg l?1) than the other rivers. Background TSS concentration on the Upper Mississippi (16 mg l?1) was below a threshold (30 mg l?1) designed to protect aquatic vegetation. Our model‐predicted concentrations for the great rivers are an attempt to estimate background concentrations for water quality indicators independent from thresholds based on percentiles or derived from stressor‐response relationships.  相似文献   
7.
Matt McDonald 《环境政策》2016,25(6):1058-1078
Environmental nongovernmental organizations (NGOs) in Australia have struggled to generate and sustain public concern about climate change. If debates about climate policy can be viewed as sites of contestation between competing actors, Australia’s environmental NGOs have found it difficult to compete against countervailing forces that have sought to shape public attitudes to climate action and the contours of policy responses. While to a significant degree this reflects the power of those forces and the sentiments of the government of the day, there is also a case to be made that some of Australia’s most prominent environmental NGOs have appeared wedded to strategies inconsistent with building or sustaining public support for action or guiding policy responses. How have Australia’s largest environmental NGOs engaged climate politics, and why has this engagement taken that form? Pierre Bourdieu’s political sociology provides unique insight for coming to terms with the multifaceted nature of the constraints, opportunities, and drivers of political action, from the context of climate politics to the forces behind Australian NGOs’ engagement with that politics, and the limits of that engagement. Bourdieu’s work also suggests possible avenues for more effective forms of political communication on climate change in the Australian context.  相似文献   
8.
In this paper, the island of Tasmania is considered as a government jurisdiction. Management at this scale can conflict with sustainability in local environments. The case used to make this argument is the Tasmanian commercial rock lobster fishery. Within this fishery, Tasmania-wide management paradoxically intensifies differences at the same time as it effaces them. These differences contrast with Tasmania-wide management claims regarding sustainability. Actor-network theory is used to help approach these tensions. Zoning the fishery is put forward as a way to take into account differences to produce sustainable local outcomes.  相似文献   
9.
10.
Stream restoration practices are becoming increasingly common, but biological assessments of these improvements are still limited. Rock weirs, a type of constructed riffle, were implemented in the upper Cache River in southern Illinois, USA, in 2001 and 2003–2004 to control channel incision and protect high quality riparian wetlands as part of an extensive watershed-level restoration. Construction of the rock weirs provided an opportunity to examine biological responses to a common in-stream restoration technique. We compared macroinvertebrate assemblages on previously constructed rock weirs and newly constructed weirs to those on snags and scoured clay streambed, the two dominant substrates in the unrestored reaches of the river. We quantitatively sampled macroinvertebrates on these substrates on seven occasions during 2003 and 2004. Ephemeroptera, Plecoptera, and Trichoptera (EPT) biomass and aquatic insect biomass were significantly higher on rock weirs than the streambed for most sample periods. Snags supported intermediate EPT and aquatic insect biomass compared to rock weirs and the streambed. Nonmetric multidimensional scaling (NMDS) ordinations for 2003 and 2004 revealed distinct assemblage groups for rock weirs, snags, and the streambed. Analysis of similarity supported visual interpretation of NMDS plots. All pair-wise substrate comparisons differed significantly, except recently constructed weirs versus older weirs. Results indicate positive responses by macroinvertebrate assemblages to in-stream restoration in the Cache River. Moreover, these responses were not evident with more common measures of total density, biomass, and diversity.  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