全文获取类型
收费全文 | 890篇 |
免费 | 34篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 38篇 |
环保管理 | 255篇 |
综合类 | 120篇 |
基础理论 | 24篇 |
污染及防治 | 4篇 |
评价与监测 | 8篇 |
社会与环境 | 107篇 |
灾害及防治 | 401篇 |
出版年
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 13篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 15篇 |
2017年 | 17篇 |
2016年 | 25篇 |
2015年 | 26篇 |
2014年 | 11篇 |
2013年 | 34篇 |
2012年 | 36篇 |
2011年 | 60篇 |
2010年 | 31篇 |
2009年 | 31篇 |
2008年 | 18篇 |
2007年 | 40篇 |
2006年 | 46篇 |
2005年 | 53篇 |
2004年 | 43篇 |
2003年 | 35篇 |
2002年 | 53篇 |
2001年 | 33篇 |
2000年 | 46篇 |
1999年 | 34篇 |
1998年 | 13篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 19篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1972年 | 6篇 |
排序方式: 共有957条查询结果,搜索用时 343 毫秒
881.
882.
灰色拓扑预测理论在暴雨洪涝灾害预测中的应用 总被引:7,自引:0,他引:7
本文应用灰色理论中拓扑预测的理论方法对长江中下游地区未来几年的水灾状况作了预测试验。 相似文献
883.
Glenn E. Moglen Richard H. McCuen 《Journal of the American Water Resources Association》1990,26(1):145-156
ABSTRACT: A framework for combining economic factors and the hydrolo of detention basins is provided. The general development of economic production functions for water quality (sediment) and flood control is discussed. Example production functions are generated to compare water quality (sediment control only) and flood control. For the given example, the design of a detention basin for downstream sediment control is economically unwarranted. When compared to on-site detention facilities, regional detention structures appear to be more practical from an economic standpoint for water quality control. Since sediment was the only water quality parameter assessed, it is entirely possible that the design of a detention basin for water quality control would be justified if the effects of all pollutants of concern could be quantified. Policy aspects of detention facilities that relate to the economics of water quality control are also discussed. 相似文献
884.
885.
论湖南生态环境恶化加剧了洪旱灾害 总被引:2,自引:0,他引:2
总结了湖南近年洪旱灾害特征,除了气象因素以外,论证了灾害加剧频发的原因是人口激增与资源不合理开发导致了生态环境恶化:森林锐减,水土流失,环境污染,洞庭湖生态环境变化的影响及水利失修等,据此,提了防灾减灾对策建议。 相似文献
886.
Environmental impacts of the construction-phase drainage congestion along the Dhaka City Flood Control Embankment were assessed
by a pilot questionnaire survey (in 1991) among the target population adjacent to the embankment. The results of the survey
indicated that, despite significant alleviation of river flooding, the majority of the respondents experienced a new type
of flood problem in the form of stagnant water inside the embankment, immediately following its construction. Not only had
this stagnant water flooded and damaged their property, it had exposed them to a number of other environmental problems, such
as accumulation of municipal sewage, foul odors, mosquitoes, and growth of water hyacinth. The study found that the respondents'
assessments of these environmental problems differed significantly according to the magnitude of the impact of stagnant water
upon two subgroups within the target population. A postsurvey follow-up in 1994 indicated that this problem of drainage congestion
had largely been alleviated by completing the construction of a number of drainage regulators. The study concludes by stressing
the importance of synchronizing the construction of drainage structures with that of the embankment systems and by underlining
policy implications for flood-vulnerable land use adjacent to embankments. 相似文献
887.
本文从气象与水文角度分析了赣江上中游1992年3月特大水灾的成因,简述了灾情,对赣江洪水今后演变趋势及水灾防治对策作了初步探讨。 相似文献
888.
889.
延安“93.8”暴雨洪水抗御经验和致灾因素分析 总被引:1,自引:0,他引:1
本文分析了延安“93·8”暴雨洪水概况和致灾因素,总结了当地抗御暴雨洪灾的经验,并就该地区基层防汛工作、淤地坝渡汛安全和河道清障等防汛减灾措施提出了建议。 相似文献
890.
One of the major changes in flash-flood mitigation in the past decade is the number of communities that have implemented warning systems. The authors conducted a survey of 18 early-warning systems in the United States developed by communities or regions to provide protection against flash floods or dam failures. Problems revealed by the study included the following: equipment malfunctions, inadequate maintenance funding, inconsistent levels of protection and expenditure, inconsistent levels of expectations and formalization, varying levels of local commitment to the systems, underemphasis on response capability, and a tendency to over-rely on warning systems. The study also revealed some unanticipated benefits experienced by the survey communities: the warning systems serve as valuable data collection tools, a great deal of interagency cooperation has been demonstrated, and warning systems offer increased alternatives to structural modification projects. The interjurisdictional nature of drainage basins, the evolving roles of the various federal agencies involved in flood mitigation, and the lack of governmental standards of operations for flood warning systems are issues that must be considered as communities make decisions regarding the adoption of warning systems. The record on these systems is too short for a precise assessment of how successful they are; however, results of the study indicate that if the goal of reducing loss of life and property from flooding is to be achieved, warning systems must be only one part of a comprehensive flood loss reduction program. 相似文献