首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   124篇
  免费   4篇
  国内免费   20篇
安全科学   5篇
废物处理   2篇
环保管理   26篇
综合类   48篇
基础理论   9篇
污染及防治   6篇
评价与监测   7篇
社会与环境   11篇
灾害及防治   34篇
  2023年   3篇
  2022年   2篇
  2021年   1篇
  2020年   3篇
  2019年   2篇
  2018年   2篇
  2017年   4篇
  2016年   4篇
  2015年   3篇
  2014年   2篇
  2013年   8篇
  2012年   3篇
  2011年   13篇
  2010年   6篇
  2009年   6篇
  2008年   6篇
  2007年   6篇
  2006年   5篇
  2005年   9篇
  2004年   7篇
  2003年   4篇
  2002年   3篇
  2001年   2篇
  2000年   7篇
  1999年   1篇
  1998年   5篇
  1997年   3篇
  1996年   3篇
  1995年   4篇
  1994年   8篇
  1992年   3篇
  1991年   1篇
  1990年   3篇
  1988年   2篇
  1987年   1篇
  1982年   1篇
  1977年   1篇
  1976年   1篇
排序方式: 共有148条查询结果,搜索用时 11 毫秒
91.
利用1995—2020年青海省雷电灾害资料,研究该区域雷电灾害时空分布特征。结果表明:1995—2006年青海省雷电灾害呈增加趋势;2007—2015年青海省雷电灾害呈下降趋势;2016—2020年青海省雷电灾害呈平稳略有上升趋势。青海省雷电灾害空间分布呈,东多西少、南多北少分布特征,其中,雷灾密集区位于西宁市辖区、大通县、河南县、湟中县和互助县区域。1995—2020年,雷电灾害造成青海省人员伤亡282人,平均11人/a,同时对办公设备,广电、电力系统、通讯系统和住宅等方面也造成了损失,其经济损失达1 247.12万元,平均47.97万元/a。  相似文献   
92.
基于灰色理论和气象灾害普查资料对黑龙江省暴雨洪涝灾害时空分布特征进行了分析并进行了灾变预测。黑龙江省暴雨洪涝灾害主要发生在5-9月,其中7月损失最大;1990年以来暴雨次数虽然有所减少,但暴雨洪涝造成的损失却明显增加;黑龙江省暴雨洪涝灾害可划分为严重洪涝区、重洪涝区、中洪涝区和轻洪涝区,严重洪涝区位于松花江及其支流沿岸的大庆市、伊春市、齐齐哈尔市、佳木斯市和哈尔滨市。根据灰色灾变预测理论预测2013年出现严重暴雨洪涝灾害(全省农作物受灾面积≥500 000 hm2、可比经济损失≥50 000万元)的可能性最大,其次是2016年。  相似文献   
93.
地震灾害导致企业资产遭受损失,为了科学合理的制定灾区企业恢复生产和重建工作的计划,需要对企业灾害损失进行快速的评估.本文从统计的角度提出了一种估算灾区企业固定资产损失情况的方法,并以汶川地震为例对此方法进行效验.  相似文献   
94.
农业环境污染事故损失评价方法研究   总被引:8,自引:0,他引:8  
通过对农业环境污染事故的分析,将农业环境污染事故造成的损失分为4部分.即农业生物污染损失、人体伤害造成的损失、农业资源损失和控制污染物扩散及治理污染所需费用.对各污染损失的计算、评估方法进行了探讨,在此基础上对已有方法进行了必要的改进,提高了各种方法的可操作性,并提出了农业环境污染事故损失评估中应注意的问题.研究成果对农业环境污染事故损失评估具有一定的参考价值.  相似文献   
95.
India is the first country to introduce environmental legislation in the constitution but because of lengthy legal procedures, it is very difficult to control environmental deterioration. There are many factors responsible for this deterioration. Coal mining is one such activity where deterioration is very severe and the present communication aims this aspect. Coal is the one of the most essential mineral having large reserves in India. It’s mining and beneficiation produce a variety of pollutants. The main pollutants emitted during the processing of coal are green house gases, coal dust and acid mine drainage. Many reports on different aspects of coal mining are available including reports on emission of different pollutants but the present work is probably only of it’s kind in which the authors have tried to determine environment liability directly in terms of economy. It was found that greenhouse liabilities, coal dust liability and sulphur liability are accounted for 12.07, 5.0 and 101.97 US$, making an overall 2.4% of the total economic gains due to coal mining. During the calculations approximate number of total workers and other parameters have been taken into consideration. Who pays for this irreversible damage is a question. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   
96.
为了检验区域农业市场化发展对于水土流失的影响,以江西省为例,结合对水土流失驱动力因素的分析,构建了区域水土流失驱动力模型,并据此分析了1988~2000年区域农业市场化发展对水土流失治理的贡献。结果表明,农业市场化程度的提高,有利于提高水土流失治理的效率。1988~2000年,江西省的农业市场化水平提高了15.2%,由此通过农户行为作用,水土流失面积减少61.4471万hm2,相当于2000年水土流失面积的18.36%。因此,区域农业市场化程度每提高1%,水土流失面积将减少40.43万hm2。最后,就区域农业市场化进程中如何进一步推进水土流失治理,提高水土保持效果,提出了相关建议。  相似文献   
97.
汤泉 《灾害学》1994,9(4):35-39
本文收集了我国近期数十次地震灾害所造成经济损失的资料,得出了震灾经济损失在我国不同地区随震级的变化特征。通过引入地震灾害损失率的概念,对震害评估指标体系作了讨论,并由此得出一种简捷的震害评估方法。  相似文献   
98.
Not all disease activity causes an impact. Not all impacts are negative. The aim of this study was to examine a method that could conceptually specify when impacts occur and that could quantify both negative and positive disease impacts. For this study, dwarf mistletoe (Arceuthobium douglasi) of Douglas fir (Pseudotsuga menziesii) in southwestern Oregon was used as a case study. The method uses six variables for forest growth, mortality, and stand structure, and six categorical disease severity scores. The impact model displays stands as points in multidimensional scaling space, where relative position is determined by values of the six stand variables. Positions in this two-dimensional space change when stand characteristics change. Differences associated with disease severity could be traced as trajectories, and impact was quantified using the length and direction of these trajectories. This multivariate impact assessment method was contrasted to impact assessments based on single variables. Methods based on multiple variables offer a useful way of characterizing impact on multiple objectives. The model indicates that dwarf mistletoe has positive, negative, and neutral impacts and that these could be illustrated and quantified using this method.  相似文献   
99.
ABSTRACT: An allocation model for irrigation water cost, based on the Use of Facilities method, is presented. The model is developed for large-scale irrigation systems which may include multipurpose reservoirs, irrigation control works, pump stations and irrigation canals of various orders. The model accounts for the water conveyance losses as well as the water gains in the irrigation canals, and their effects on irrigation cost. It is applied to the irrigation distribution system of the Nile Valley in Egypt, which contains the High Aswan Dam, 16 irrigation structures, 12 pump stations, and numerous irrigation canals. The irrigation water cost at 29 areas representing the Nile Valley is determined.  相似文献   
100.
ABSTRACT: Estimations of runoff volumes from urban areas can be made by the equation Q = a A σ(Pe– b), where Q is the runoff volume, a is the part of the total area A Contributing to runoff, Pe is the rainfall amount for a single event, and b is the initial rainfall losses. For the evaluation of a and b, rainfall/runoff measurements were made in five areas of sizes between 0.035 km2 and 1.450 km2. By linear regression analysis of rainfall volumes versus runoff volumes, the initial rainfall losses were found to vary from 0.38 mm to 0.70 mm for the different areas. The parts of the areas contributing to runoff were found to be proportional to the impermeable parts of the mas. The equation is applicable in urban areas with well defined paved surfaces and roofs and with a negligible amount of runoff from permeable areas.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号