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991.
刘敬禹 《中国环境管理干部学院学报》2002,12(3):30-33
本文通过对城市水环境的形成以及加强水环境建设对整个城市建设舒适度的影响和作用的剖析,试着引用了一种国际上较为流行的对河流综合整治的方法,对秦皇岛城市水环境建设提出了一点建议。 相似文献
992.
993.
G. Darrel Jenerette Jay Lee David W. Waller Robert E. Carlson 《Environmental management》2002,29(1):67-75
The ecoregion concept is a popular method of understanding the spatial distribution of the environment', however, it has yet
to be adequately demonstrated that the environment is distributed in accordance with these bounded units. In this paper, we
generated a testable hypothesis based on the current usage of ecoregions: the ecoregion classification will allow for discrimination
between lakes of different water quality. The ecoregion classification should also be more effective better than a comparably
scaled classification based on political boundaries, land-use class, or random grouping. To test this hypothesis we used the
Environmental Monitoring and Assessment Program (EMAP) lake water chemistry data from the northeast United States. The water
chemistry data were reduced to four components using principal component analysis. For comparison to an optimal grouping of
these data we used K-means cluster analysis to define the extent at which these lakes could be segregated into distinct classes.
Jackknifed discriminant analysis was used to determine the classification rate of ecoregions, the three alternative spatial
classification methods, and the clustering algorithm. The classification based on ecoregions was successful for 35% of the
lakes included in this study, in comparison to the clustered groups accuracy of 98%. These results suggest that the large
scale spatial distribution of ecosystem types is more complicated than that suggested by the present ecoregion boundaries.
Further tests of ecoregion delineations are needed and alternative large-scale management strategies should be investigated. 相似文献
994.
Sandra L Postel 《Natural resources forum》2003,27(2):89-98
A fundamentally new approach to water and human development will be needed during this new century if we are to secure sufficient freshwater to meet the needs of some 9 billion people while at the same time protecting the critical ecosystem services upon which the human economy depends. Signs of unsustainable water use — including falling water tables, shrinking lakes, and the drying up of rivers and streams — are widespread and spreading. In many regions, greater modification and appropriation of freshwater systems for human purposes will yield greater costs than benefits and create the risk of irreversible losses of species and ecosystem services. A new mindset is needed to guide water use and management in this new century, one that views the human water economy as a subset of nature's water economy. Living within nature's limits will require that societies satisfy the basic needs of people and ecosystems before non-essential water demands are met. It will require on the order of a doubling of water productivity. And it will require stronger institutions to encourage equitable sharing of water to alleviate tensions within and between countries. 相似文献
995.
关于创建节水型城市的探讨 总被引:4,自引:0,他引:4
为了有效的缓解目前我国城市水资源严重短缺的现状,国家提出了大力创建节水型城市口号。为了对实践工作有一定的指导作用,本文重点对节水及节水型城市的内涵进行了剖析,特别对节水型城市内涵提出了自己的见解。以此同时,运用上述的理论,分析了目前我国在创建节水型城市工作中存在的主要问题,并结合国外节水的经验,提出了有建设性的几点建议。 相似文献
996.
Healthy watersheds provide valuable services to society, including the supply and purification of fresh water. Because these natural ecosystem services lie outside the traditional domain of commercial markets, they are undervalued and underprotected. With population and development pressures leading to the rapid modification of watershed lands, valuable hydrological services are being lost, which poses risks to the quality and cost of drinking water and the reliability of water supplies. Increasing the scale and scope of programmes to protect hydrological services requires policies that harmonize land uses in watersheds with the provision of these important natural services. This article summarizes key attributes of hydrological services and their economic benefits; presents a spectrum of institutional mechanisms for safeguarding those services; discusses programmes in Quito (Ecuador), Costa Rica and New York City; and offers some lessons learned and recommendations for achieving higher levels of watershed protection. 相似文献
997.
本文以大量事实论述了上海市由于水质污染,不仅严重威胁着上海市民的身体健康,而且已导致上海市严峻的水荒灾害问题。文章还从历史回顾中论证了上海市在治理水质污染方面的失策,并根据国内外的经验教训,提出了解决上海市水荒同题的对策和建议。 相似文献
998.
六道沟小流域主要灌木林地土壤干化研究 总被引:2,自引:0,他引:2
本文通过野外定位试验研究了黄土高原水蚀风蚀交错带典型区域陕西神木县六道沟小流域沙柳、柠条林地土壤水分状况。该区域主要灌木林地土壤水分亏缺严重。在沙柳林地,天然降水的补给深度约为0—100cm土层.土壤干层范围为0—480cm,在柠条林地,天然降水的补给深度约为0—200cm土层,土壤干层超过600cm,土壤质地、坡位等也影响灌木林地土壤干化层分布。 相似文献
999.
Analysis of a rural water supply project in three communities in Mali: Participation and sustainability 总被引:1,自引:0,他引:1
This paper presents a qualitative assessment of the participatory water management strategies implemented at the community level in rural Mali through a water supply project — The West Africa Water Initiative (WAWI) — coordinated by World Vision International, a non‐governmental and humanitarian organization. Data for the study were generated through a combination of primary and secondary sources in three villages. Results of the study indicate that while community‐based rural water supply is a positive step in responding to the needs of rural Malians, the installation of boreholes with hand pumps informed merely by consultative participatory approaches and limited extension involvement will not necessarily proffer sustainable rural water supply in the region. A “platform” approach to rural water supply management that can mobilize the assets and insights of different social actors to influence decision making at all stages, including the design and choice‐of‐technology stages, in water supply interventions is instead advocated. 相似文献
1000.
Key aspects of environmental management exist within a legislative framework. The Rivers and Foreshores Improvement Act 1948 (NSW) and several Regional Environmental Plans created under the Environmental Planning and Assessment Act 1979 (NSW) make reference to ‘the top of the bank’ for defining areas of protected land adjacent to rivers, within which development
consent may be required. It is an arbitrary term and its use within the Rivers and Foreshores Improvement Act 1948 (NSW) leads to confusion. This paper examines the range of definitions of ‘the top of the bank’ in respect of natural watercourses
and aims to provide a more lucid and effective definition that will clarify existing ambiguities in legal interpretation.
The paper examines the historical origins of the phrase ‘top of the bank’, finding that stereotyped Eurocentric views of what
a river ‘should look like’ have impaired the legal definition for Australian rivers, thereby influencing common law and the
development of statutory definitions. Judicial applications of the phrase ‘top of the bank’ are examined from a geomorphological
perspective, demonstrating the misconceptions of the term in a legal context. The paper identifies the existence of widespread
support for the need to protect land adjacent to rivers in the interests of environmental, economic and social sustainability.
It concludes by calling for legislative reform that is both tailored to the individual site and consistent with overarching
goals at the catchment scale. 相似文献