全文获取类型
收费全文 | 594篇 |
免费 | 25篇 |
国内免费 | 45篇 |
专业分类
安全科学 | 15篇 |
废物处理 | 2篇 |
环保管理 | 262篇 |
综合类 | 163篇 |
基础理论 | 115篇 |
污染及防治 | 56篇 |
评价与监测 | 24篇 |
社会与环境 | 23篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 16篇 |
2020年 | 10篇 |
2019年 | 9篇 |
2018年 | 6篇 |
2017年 | 13篇 |
2016年 | 20篇 |
2015年 | 19篇 |
2014年 | 21篇 |
2013年 | 34篇 |
2012年 | 16篇 |
2011年 | 50篇 |
2010年 | 30篇 |
2009年 | 48篇 |
2008年 | 39篇 |
2007年 | 45篇 |
2006年 | 27篇 |
2005年 | 15篇 |
2004年 | 21篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 19篇 |
2000年 | 18篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 14篇 |
1995年 | 8篇 |
1994年 | 13篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有664条查询结果,搜索用时 21 毫秒
361.
Muschal M 《Journal of environmental management》2006,80(3):266-278
A linear engineering project--i.e. a pipeline--has a potential long- and short-term impact on the environment and on the inhabitants therein. We must find better, less expensive, and less time-consuming ways to obtain information on the environment and on any modifications resulting from anthropic activity. We need scientifically sound, rapid and affordable assessment and monitoring methods. Construction companies, industries and the regulating government organisms lack the resources needed to conduct long-term basic studies of the environment. Thus there is a need to make the necessary adjustments and improvements in the environmental data considered useful for this development project. More effective and less costly methods are generally needed. We characterized the landscape of the study area, situated in the center and north-east of Argentina. Little is known of the ecology of this region and substantial research is required in order to develop sustainable uses and, at the same time, to develop methods for reducing impacts, both primary and secondary, resulting from anthropic activity in this area. Furthermore, we made an assessment of the environmental impact of the planned linear project, applying an ad hoc impact index, and we analyzed the different alternatives for a corridor, each one of these involving different sections of the territory. Among the alternative corridors considered, this study locates the most suitable ones in accordance with a selection criterion based on different environmental and conservation aspects. We selected the corridor that we considered to be the most compatible--i.e. with the least potential environmental impact--for the possible construction and operation of the linear project. This information, along with suitable measures for mitigating possible impacts, should be the basis of an environmental management plan for the design process and location of the project. We pointed out the objectivity and efficiency of this methodological approach, along with the possibility of integrating the information in order to allow for the application thereof in this type of study. 相似文献
362.
A Spatially Explicit Resource-Based Approach for Managing Stream Fishes in Riverscapes 总被引:1,自引:0,他引:1
The article describes a riverscape approach based on landscape ecology concepts, which aims at studying the multiscale relationships
between the spatial pattern of stream fish habitat patches and processes depending on fish movements. A review of the literature
shows that few operational methods are available to study this relationship due to multiple methodological and practical challenges
inherent to underwater environments. We illustrated the approach with literature data on a cyprinid species (Barbus barbus) and an actual riverscape of the Seine River, France. We represented the underwater environment of fishes for different discharges
using two-dimensional geographic information system-based maps of the resource habitat patches, defined according to activities
(feeding, resting, and spawning). To quantify spatial patterns at nested levels (resource habitat patch, daily activities
area, subpopulation area), we calculated their composition, configuration, complementation, and connectivity with multiple
spatial analysis methods: patch metrics, moving-window analysis, and least cost modeling. The proximity index allowed us to
evaluate habitat patches of relatively great value, depending on their spatial context, which contributes to the setting of
preservation policies. The methods presented to delimit potential daily activities areas and subpopulation areas showed the
potential gaps in the biological connectivity of the reach. These methods provided some space for action in restoration schemes. 相似文献
363.
364.
365.
高速公路人文景观评价的难点在于人文景观影响因素的确定和指标的量化,由于其不确定性而且受到主观因素的影响很大,将其尽量量化是较好的办法.本文结合高速公路人文景观特点提出了其评价指标体系,并通过层次分析法和模糊综合评价对各指标进行了具体分析. 相似文献
366.
Global environmental and societal changes threaten the cultures of indigenous peoples and local communities (IPLC). Despite the importance of IPLC worldviews and knowledge to sustaining human well-being and biodiversity, risks to these cultural resources are commonly neglected in environmental governance, in part because impacts can be indirect and therefore difficult to evaluate. Here, we investigate the connectivity of values associated with the relationship Ngātiwai (a New Zealand Māori tribe) have with their environment. We show that mapping the architecture of values-environment relationships enables assessment of how deep into culture the impacts of environmental change or policy can cascade. Our results detail how loss of access to key environmental elements could potentially have extensive direct and cascading impacts on the cultural values of Ngātiwai, including environmental responsibilities. Thus, considering only direct effects of environmental change or policy on cultural resources, or treating IPLC social-ecological relations simplistically, can severely underestimate threats to cultures.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01670-3. 相似文献
367.
As the human activity footprint grows, land-use decisions play an increasing role in determining the future of plant and animal species. Studies have shown that urban and agricultural development cannot only harm species populations directly through habitat destruction, but also by destroying the corridors that connect habitat patches and populations within a metapopulation. Without these pathways, populations can encounter inbreeding depression and degeneration, which can increase death rates and lower rates of reproduction. This article describes the development and application of the FRAGGLE model, a spatial system dynamics model designed to calculate connectivity indices among populations. FRAGGLE can help planners and managers identify the relative contribution of populations associated with habitat patches to future populations in those patches, taking into account the importance of interstitial land to migration success. The model is applied to the gopher tortoise (Gopherus polyphemus), a threatened species whose southeastern U.S. distribution has diminished significantly within its native range due to agricultural and urban development over the last several decades. This model is parameterized with life history and movement traits of the gopher tortoise in order to simulate population demographics and spatial distribution within an area in west-central Georgia that supports a significant tortoise population. The implications of this simulation modeling effort are demonstrated using simple landscape representations and a hypothetical on land-use management scenario. Our findings show that development resulting in even limited habitat losses (10%) may lead to significant increases in fragmentation as measured by a loss in the rate of dispersions (31%) among area subpopulations. 相似文献
368.
Thomas D. Harwood Xiangming Xu Marco Pautasso Mike J. Jeger Michael W. Shaw 《Ecological modelling》2009
We developed a stochastic simulation model incorporating most processes likely to be important in the spread of Phytophthora ramorum and similar diseases across the British landscape (covering Rhododendron ponticum in woodland and nurseries, and Vaccinium myrtillus in heathland). The simulation allows for movements of diseased plants within a realistically modelled trade network and long-distance natural dispersal. A series of simulation experiments were run with the model, representing an experiment varying the epidemic pressure and linkage between natural vegetation and horticultural trade, with or without disease spread in commercial trade, and with or without inspections-with-eradication, to give a 2 × 2 × 2 × 2 factorial started at 10 arbitrary locations spread across England. Fifty replicate simulations were made at each set of parameter values. Individual epidemics varied dramatically in size due to stochastic effects throughout the model. Across a range of epidemic pressures, the size of the epidemic was 5–13 times larger when commercial movement of plants was included. A key unknown factor in the system is the area of susceptible habitat outside the nursery system. Inspections, with a probability of detection and efficiency of infected-plant removal of 80% and made at 90-day intervals, reduced the size of epidemics by about 60% across the three sectors with a density of 1% susceptible plants in broadleaf woodland and heathland. Reducing this density to 0.1% largely isolated the trade network, so that inspections reduced the final epidemic size by over 90%, and most epidemics ended without escape into nature. Even in this case, however, major wild epidemics developed in a few percent of cases. Provided the number of new introductions remains low, the current inspection policy will control most epidemics. However, as the rate of introduction increases, it can overwhelm any reasonable inspection regime, largely due to spread prior to detection. 相似文献
369.
Preface to the selected papers on spatially explicit landscape modelling: Current practices and challenges 总被引:1,自引:0,他引:1
In the past 30 years, the notion of landscape has emerged in ecology as a result of both theoretical strategies and practical aspects of land use. This has generated a variety of computerized models addressing both objectives and techniques. Scientists model landscapes for at least two reasons: to better understand the landscape dynamics themselves (called intrinsic needs) and to offer a realistic frame to support other ecological processes (extrinsic needs). This special issue concerns both needs and illustrates the way socioeconomic and/or ecological mechanisms of various landscapes have been understood through modelling approaches. It outlines the links between landscape and model concepts, focusing on one hand on several landscape types (agricultural, forested and aquatic) and on the other hand on several landscape model characteristics (explicit or neutral, dynamic or static, patchy or continuous and multi- or mono-scale). The patterns and processes of each landscape model presented in this issue, in particular, should be analysed in order to highlight the way they are contributing to the landscape ecology discipline. We finally argue that the discipline can now offer a theoretical dimension to landscape dynamics, aiming at understanding the possible mechanism unity underlying this complex object. 相似文献
370.
景观及视觉影响评价初探 总被引:10,自引:0,他引:10
总结和论述了景观及视觉影响评价的概念及评价的过程、内容与方法等,结合我国的实际情况提出了开展此项工作的建议。由于景观及视觉影响不同于通常的污染影响,具有直接可见性和不易改变性等特点,故应及早重视,使发展项目所制定的计划与景观及视觉环境相协调。该评价方法主要包括计算机技术支持下的图形叠加法和GIS法等。 相似文献