全文获取类型
收费全文 | 863篇 |
免费 | 30篇 |
国内免费 | 22篇 |
专业分类
安全科学 | 35篇 |
环保管理 | 247篇 |
综合类 | 109篇 |
基础理论 | 15篇 |
污染及防治 | 2篇 |
评价与监测 | 7篇 |
社会与环境 | 104篇 |
灾害及防治 | 396篇 |
出版年
2023年 | 4篇 |
2022年 | 12篇 |
2021年 | 13篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 15篇 |
2017年 | 14篇 |
2016年 | 23篇 |
2015年 | 26篇 |
2014年 | 10篇 |
2013年 | 33篇 |
2012年 | 33篇 |
2011年 | 59篇 |
2010年 | 31篇 |
2009年 | 26篇 |
2008年 | 15篇 |
2007年 | 36篇 |
2006年 | 45篇 |
2005年 | 51篇 |
2004年 | 44篇 |
2003年 | 32篇 |
2002年 | 51篇 |
2001年 | 33篇 |
2000年 | 46篇 |
1999年 | 33篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 19篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 5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 | 3篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1972年 | 6篇 |
排序方式: 共有915条查询结果,搜索用时 296 毫秒
71.
72.
长江三角洲及其附近地区两千年来水灾的研究 总被引:6,自引:1,他引:5
通过对长江三角洲及其附近地区两千年来水灾生成频率和强度的分析。认为两晋、南北朝时期和南宋、元、明、清时期是两千年来本区的主要水灾期。对照两千年来中国东部气候变化、海面升降与长江口河道变迁关系,认为在本区水灾生成事件中,气候因素起着主导控制作用。当然,人类活动对本区水灾生成的影响也不容忽视。本地区近百年来的旱涝灾害规律可用非线性科学的方法进行研究,旱涝灾害的准60年、准35年和准11年的长周期变化与地球自转速度、地极移动和太阳黑子活动的3个周期变化基本一致。本地区气候系统的行为具有混沌特征。这是线性逼近和周期叠加预报方法难以得出灾害预报正确结果的原因,但气候系统半个月的确定性预测可以实现。 相似文献
73.
近50年来湖南省旱洪灾害及其时空分布 总被引:11,自引:5,他引:6
利用 194 9年以来湖南省 9个代表站的降水资料 ,提出了湖南省旱洪灾害的等级标准 ,分析了湖南省旱洪灾害及其时空分布和旱洪重灾区的形成原因 相似文献
74.
区域洪涝灾害风险的模糊综合评价与预测 总被引:1,自引:0,他引:1
以广西1992~2006年洪涝灾情数据为基础,选取适当的评价指标,用基于遗传算法、特征值法和优化算法的投影寻踪法和层次分析法确定各评价指标的分类权重和排序权重,用优化算法进行综合得到组合权重,经过加权求和得出洪涝灾害的模糊综合评价,进而对15个评价对象进行了分类排序,其分类结果很好地反映了洪涝灾情的实际情况。在以上模糊综合评价结果的基础上,利用距离贴近度进一步计算和分析各个评价指标之间的贴近度,并由择近原则确定各个评价指标之间在洪涝灾害评价中的相关程度。同时,建立了基于改进的灰色GM(1,1)的时间响应式的灾变年份预测模型。 相似文献
75.
76.
Shue Tuck Wong 《Journal of the American Water Resources Association》1979,15(2):396-403
ABSTRACT: Human behavior and response towards storm hazard are examined in this study. One-hundred and twenty flood victims in West Vancouver, British Columbia, were administered a sentence completion test to ascertain how these victims behaved and responded to the flash flood of July 12, 1972. The sentence completion test consisted of 11 sentence stems. Seven of these dealt with the respondent's behavior toward the storm experience, and four with the issue of internal vs. external locus of control. Completions of the seven sentence stems at three time situations showed that West Vancouverites expressed the normal reactions of fear and anxiety before the storm; showed negative emotions during the storm; and displayed a feeling of mutual cooperation after the storm. Completions of the remaining four sentence stems revealed that West Vancouverites emphasized the importance of internal factors, viz., autonomy, drive and hard work, in controlling their lives. They recognized God as a benevolent - protective and almighty - powerful figure. Forty percent of the respondents did not believe in luck, while 8 percent regarded it as important in their lives. One might conclude that West Vancouverites could cope with natural hazardous threats better than those who rely on external factors in directing their lives. 相似文献
77.
Andrew A. Dzurik 《Journal of the American Water Resources Association》1979,15(2):420-425
ABSTRACT: Methods of floodplain management are changing in the United States. There has been a gradual shift in emphasis from “flood control” to “management” of the floodplain. The complexities of multilevel governmental involvement in floodplain management demand an analysis of a new means to coordinate these efforts. It is the intent of this paper to discuss the role of the Corps of Engineers in this area and the problems the Corps has encountered in its endeavors. The occurrence of these problems indicates that there is a need to strengthen the federal role to ensure a comprehensive view of floodplain management. 相似文献
78.
Thomas N. Debo 《Journal of the American Water Resources Association》1980,16(4):654-660
ABSTRACT: Storm water management is a concept being applied in many urban areas to deal with the increasing problems of storm runoff control and flood damage prevention. This paper introduces the concept and describes the recently completed storm water management program in Columbus, Georgia. Columbus has spent five years and over $200,000 in the development of their problem which includes several basic elements: soils inventory and analysis, hydrologic data collection, sediment and erosion control ordinance, storm water management handbook, urban flood simulation model, interdepartment coordination study, drainage problem categorization study, and a pilot basin study. The results of the pilot basin study are presented including example output from the urban simulation model. The computer output illustrates both the hydrologic-hydraulic and economic capabilities of the model. 相似文献
79.
Marion Babcock Bruce Mitchell 《Journal of the American Water Resources Association》1980,16(3):532-537
ABSTRACT: This study is an examination of the relationship between flooding and property values for an urban community in southwestern Ontario which has a lengthy history of flooding. As well, peoples’perceptions of the effect of flooding on property values is discussed. Analysis of sales prices and assessment data demonstrated no statistically significant differences in values of property for residences located in high- and low-risk areas either before or after a major flood in 1974. With both the high- and low-risk areas, sales prices after the 1974 flood were significantly higher than sales prices before the flood. The perceived property values followed a similar pattern. We concluded that differences in flood risk and flood experience did not adversely affect actual or perceived long-term property values. 相似文献
80.
Brain M. Reich Kenneth G. Renard 《Journal of the American Water Resources Association》1981,17(1):67-74
ABSTRACT: Flood frequency analyses are frequently being made using widely available computer programs. Serious errors can result from blind acceptance of such results. Visual interpretation of observed flood series can be used for evaluation on frequency paper with compatible scales. Such frequency papers are presented in the paper. In ephemeral streams, more infrequent floods may constitute a separate set from the more frequent floods because (a) runoff producing storms cover only a portion of the contributing area, (b) transmission losses in the normally dry streambed may reduce the peak flow, and (c) some runoff may be stored in stock water ponds which therefore leads to partial area runoff. The Cunnane plotting position used in this paper is superior to the more widely used Weibull equation, having a mathematically sound basis for locating observed floods on an assumed probability. 相似文献