全文获取类型
收费全文 | 3132篇 |
免费 | 128篇 |
国内免费 | 194篇 |
专业分类
安全科学 | 147篇 |
废物处理 | 17篇 |
环保管理 | 781篇 |
综合类 | 1293篇 |
基础理论 | 205篇 |
污染及防治 | 271篇 |
评价与监测 | 579篇 |
社会与环境 | 120篇 |
灾害及防治 | 41篇 |
出版年
2023年 | 42篇 |
2022年 | 45篇 |
2021年 | 73篇 |
2020年 | 96篇 |
2019年 | 51篇 |
2018年 | 50篇 |
2017年 | 85篇 |
2016年 | 111篇 |
2015年 | 126篇 |
2014年 | 140篇 |
2013年 | 154篇 |
2012年 | 131篇 |
2011年 | 241篇 |
2010年 | 88篇 |
2009年 | 235篇 |
2008年 | 198篇 |
2007年 | 197篇 |
2006年 | 152篇 |
2005年 | 128篇 |
2004年 | 116篇 |
2003年 | 116篇 |
2002年 | 104篇 |
2001年 | 87篇 |
2000年 | 87篇 |
1999年 | 83篇 |
1998年 | 81篇 |
1997年 | 62篇 |
1996年 | 42篇 |
1995年 | 53篇 |
1994年 | 65篇 |
1993年 | 39篇 |
1992年 | 24篇 |
1991年 | 18篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 12篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1973年 | 6篇 |
1971年 | 4篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有3454条查询结果,搜索用时 15 毫秒
991.
992.
993.
白炜 《中国环境管理干部学院学报》2004,14(1):20-23
水是关系社会可持续发展的重要资源,但是我国水管理的弊端造成水资源状况不容乐观。针对这一情况,2002年《水法》的修改重点之一是加强了水资源统一管理。本文从统一管理的必要性出发,分析了《水法》有关水资源统一管理的规定,并指出了有待完善之处。 相似文献
994.
Rice versus fish revisited: On the integrated management of floodplain resources in Bangladesh 总被引:2,自引:0,他引:2
Disproportionately little attention has been paid to the dry season trade‐off between rice and (inland capture) fish production on the floodplains of Bangladesh, compared to the same trade‐off during the flood season. As the rural economy grows increasingly dominated by dry‐season irrigated rice production, and floodplain land and water come under ever‐increasing pressure during the dry winter months, there is an urgent need to focus attention on these dry months that are so critical to the survival and propagation of the floodplain resident fish, and to the poor people that depend on these fish for their livelihood. This article examines three important dry‐season natural resource constraints to floodplain livelihoods in Bangladesh, and finds a common factor at the heart of all three: rice cultivation on lands at low and very low elevations. The article articulates the system interlinkages that bind these constraints and the long‐run trend towards irrigated rice cropping on lower‐lying lands, and suggests a management approach based on locally tailored strategies to arrest this trend. Apart from its direct relevance to the floodplains of Bangladesh, which support more than 100 million people, these lessons have relevance for river floodplain systems elsewhere in the developing world, notably the Mekong Delta. 相似文献
995.
A system dynamics model to facilitate public understanding of water management options in Las Vegas,Nevada 总被引:12,自引:0,他引:12
Stave KA 《Journal of environmental management》2003,67(4):303-313
Water managers increasingly are faced with the challenge of building public or stakeholder support for resource management strategies. Building support requires raising stakeholder awareness of resource problems and understanding about the consequences of different policy options. One approach that can help managers communicate with stakeholders is system dynamics modeling. Used interactively in a public forum, a system dynamics model can be used to explain the resource system and illustrate the effects of strategies proposed by managers or suggested by forum participants. This article illustrates the process of building a strategic-level system dynamics model using the case of water management in Las Vegas, Nevada. The purpose of the model was to increase public understanding of the value of water conservation in Las Vegas. The effects of policies on water supply and demand in the system are not straightforward because of the structure of the system. Multiple feedback relationships lead to the somewhat counterintuitive result that reducing residential outdoor water use has a much greater effect on water demand than reducing indoor water use by the same amount. The model output shows this effect clearly. This paper describes the use of the model in research workshops and discusses the potential of this kind of interactive model to stimulate stakeholder interest in the structure of the system, engage participant interest more deeply, and build stakeholder understanding of the basis for management decisions. 相似文献
996.
In the recent decades, there have been frequent conflicts between groundwater resources and environmentally hazardous activities. An example is the construction of the new highway through the important glaciofluvial esker aquifer Nybroåsen, which passes the protection zone of the water supply for the Kalmar municipality, in the southeastern part of Sweden. The decision to build the new road through this important aquifer has been strongly questioned by the municipality and the public because the value of the water resources in Nybroåsen was not taken into consideration during the first phase of the decision-making process. Multicriteria decision aid (MCDA) is applied as a tool to structure and analyze the four road alternatives proposed in the environmental impact assessment for the above conflict. The alternatives, including the existing road, are in conflict with water resources, agriculture, natural, and cultural values. The impacts on the water resources have been predicted by a two-dimensional physically based time-variant flow and solute groundwater model, which has been calibrated and evaluated. The MCDA illustrates how it can be used to identify (1) actors and their concerns, (2) ranking of alternative road scenarios according to actors preferences, and (3) coalition groups of actors, i.e., groups that have similar views with regard to the road alternatives. The analysis shows that the two best compromise solutions obtained in the MCDA were unacceptable by the strongest coalition group, showing that either the family of criteria was not well chosen or new alternatives should have been developed. 相似文献
997.
The US Clean Water Act and habitat replacement: evaluation of mitigation sites in Orange County,California, USA 总被引:2,自引:2,他引:0
Both permit requirements and ecological assessments have been used to evaluate mitigation success. This analysis combines
these two approaches to evaluate mitigation required under Section 404 of the United States Clean Water Act (CWA) and Section
10 of the Rivers and Harbors Act, which allow developers to provide compensatory mitigation for unavoidable impacts to wetlands.
This study reviewed permit files and conducted field assessments of mitigation sites to evaluate the effectiveness of mitigation
required by the US Army Corps of Engineers for all permits issued in Orange County, California from 1979 through 1993. The
535 permit actions approved during this period allowed 157 ha of impacts. Mitigation was required on 70 of these actions,
with 152 ha of enhanced, restored, and created habitat required for 136 ha of impacts. In 15 permit actions, no mitigation
project was constructed, but in only two cases was the originally permitted project built; the two cases resulted in an unmitigated
loss of 1.6 ha. Of the remaining 55 sites, 55% were successful at meeting the permit conditions while 11% failed to do so.
Based on a qualitative assessment of habitat quality, only 16% of the sites could be considered successful and 26% were considered
failures. Thus, of the 126 ha of habitat lost due to the 55 projects, only 26 ha of mitigation was considered successful.
The low success rate was not due to poor enforcement, although nearly half of the projects did not comply with all permit
conditions. Mitigation success could best be improved by requiring mitigation plans to have performance standards based on
habitat functions. 相似文献
998.
Serveiss VB 《Environmental management》2002,29(2):145-154
Considerable progress in addressing point source (end of pipe) pollution problems has been made, but it is now recognized
that further substantial environmental improvements depend on controlling nonpoint source pollution. A watershed approach
is being used more frequently to address these problems because traditional regulatory approaches do not focus on nonpoint
sources. The watershed approach is organized around the guiding principles of partnerships, geographic focus, and management
based on sound science and data. This helps to focus efforts on the highest priority problems within hydrologically-defined
geographic areas. Ecological risk assessment is a process to collect, organize, analyze, and present scientific information
to improve decision making. The U.S. Environmental Protection Agency (EPA) sponsored three watershed assessments and found
that integrating the watershed approach with ecological risk assessment increases the use of environmental monitoring and
assessment data in decision making. This paper describes the basics of the watershed approach, the ecological risk assessment
process, and how these two frameworks can be integrated. The three major principles of watershed ecological risk assessment
found to be most useful for increasing the use of science in decision making are (1) using assessment endpoints and conceptual
models, (2) holding regular interactions between scientists and managers, and (3) developing a focus for multiple stressor
analysis. Examples are provided illustrating how these principles were implemented in these assessments. 相似文献
999.
分洪区数字地形模型建立及其应用 总被引:4,自引:0,他引:4
从实用的角度介绍了建立分洪区数字地形模型(DTM)方程,并给出了在分洪区信息可视化、分洪区特征曲线生成、分洪区二维洪水演进等等方面的应用。 相似文献
1000.
东川市土地退化(荒漠化)及其防治 总被引:5,自引:0,他引:5
分析了东川市土地退化现状:土地退化以水蚀为主,退化土地面积占总土地面积38.5%。土地退化类型主要有土壤退化、土地沙石化、土地石质化和侵蚀劣地。文章还探讨了东川市土地退化的原因,提出了土地退化防治对策。 相似文献