排序方式: 共有39条查询结果,搜索用时 31 毫秒
1.
2.
基于GIS的南京市典型蔬菜基地土壤重金属污染现状与评价 总被引:13,自引:3,他引:10
对南京市八卦洲蔬菜基地土壤中的铅、铬、铜和镉进行测定分析,利用不同的评价标准来评价其环境质量状况,同时借助GIS软件研究了污染指数的空间分布状况,并解析了其重金属污染的来源.结果表明,以自然背景值为评价标准,则蔬菜地土壤中的重金属都超过污染指标,其中镉为首要污染因子;以国标二级为评价标准,则除镉以外的三种重金属的单项污染指数值全都小于1,但其综合污染指数迭1.50,总体上属轻污染状况.南京化工因区、南京长江二桥和各种农业生产活动等可能是主要污染源. 相似文献
3.
杭州主城区大气臭氧对空气污染指数API的影响 总被引:10,自引:8,他引:2
利用2004年至2007年空气污染监测数据,比较现行API指数和修正后API指数的差异,分析修正后O3污染的变化状况,研究O3污染的季节变化。结果表明,O3作为一种新的空气污染指标,对修正后API指数的影响很大。与现行API指数相比,4年来修正后API指数的污染率大幅度增加,并且各季节的污染率越来越接近,2007年污染率在25%左右。2007年各季节修正后API指数污染天数中O3污染天数所占百分比分别是春季为52%、夏季91.6%、秋季20.8%、冬季O3,未出现污染。 相似文献
4.
5.
6.
Status of heavy metals in agricultural soils as affected by different patterns of land use 总被引:5,自引:0,他引:5
This study was conducted to determine status of heavy metals in agricultural soils under different patterns of land use. A
total of 38, 40 and 45 soil samples for bare vegetable field, greenhouse vegetable field, and grain crop field were respectively
taken from surface layer (0–20 cm) from selected experimental areas away from suburbs of ten counties (or districts or cities)
in four provinces or municipalities of Huabei plain in north China. Information of crop production history, including varieties,
rotation systems and fertilizer use, at the corresponding sampling sites was surveyed. Soil total Cu, Zn, Cd, Pb, Cr, As and
Hg were measured. The results showed that the contents of total Cu, Zn, Cd, Pb, Cr, As, and Hg in the soil samples, especially
soil total Cu and Zn contents, were higher in the bare vegetable field and the greenhouse vegetable field than that in the
grain crop field. Long-term use of excessive chemical fertilizers and organic manures in the bare vegetable field and the
greenhouse vegetable field contributed to the accumulation of Cu, Zn, and other heavy metals in the soils. The contents of
total Cu, Zn, and other heavy metals in soils increased with increasing vegetable production history of the research areas.
In comparison with the grain crop field, the comprehensive pollution indices of the seven soil heavy metals and the single-factor
pollution indices of soil Zn, Cu, Cd, Cr, and Hg based on the second criterion of Environmental Quality Standard for Soils
were significantly higher in the bare vegetable field and the greenhouse vegetable field. Soils from the greenhouse vegetable
field were slightly contaminated according to the comprehensive pollution index, and soils from the bare vegetable field and
the grain crop field were at the warning heavy metal pollution level. The soils were contaminated with Cd according to the
single-factor pollution index. The Cd pollution was relatively more serious in the bare vegetable field and the greenhouse
vegetable field than that in the grain crop field. The soils selected with different land use patterns were not contaminated
with Zn, Cu, Pb, Cr, As and Hg. 相似文献
7.
深圳市河流水质评价指标筛选方案探讨 总被引:4,自引:0,他引:4
通过计算各条河流的综合污染指数和各项水质指标的污染分担率,对深圳市8条主要河流1999--2008年水质监测数据进行分析,最终从15项常规水质指标中筛选出氨氮、总磷、生化需氧量、化学需氧量、高锰酸盐指数、石油类、挥发酚、硫化物和六价铬9项指标,建议作为深圳市河流水质评价的统一指标。 相似文献
8.
香港的空气污染指数预报 总被引:4,自引:0,他引:4
陈军 《环境监测管理与技术》1997,9(2):6-7
介绍了香港空气污染指数预报的方法和所取得的良好社会效果。通过香港空气污染指数预报的学习结合内地环境保护工作的情况,谈了几点体会。 相似文献
9.
地下水环境质量评价方法 总被引:4,自引:0,他引:4
分析了GB/T14848-93《地下水质量标准》提出的评价方法和使用范围的局限性,根据建设项目环境影响评价实际,提出采用模糊综合评判结合单因子污染指数法描述污控因子,评价地下水环境质量的方法,给出模糊综合评判方法步骤,并以实例说明其应用情况。 相似文献
10.
都江堰市城区周边农田土壤重金属污染状况分析与评价 总被引:3,自引:1,他引:2
以都江堰城区周边农耕地为对象,按照国标方法对土壤样本中的Cr、Cu、Cd、Pb、Zn五种重金属元素含量进行测定。结果表明,部分样本中的Cd、Cu含量超过国家土壤环境质量二级标准。采用单因子污染指数和土壤综合污染指数评价方法,以国家土壤环境质量二级标准为评价标准,对研究区内Cr、Cu、Cd、Pb、Zn重金属的污染状况进行评价,评价结果显示,Cu、Cd为主要污染元素,污染指数处于轻、中度污染,Cr、Pb、Zn对土壤尚未构成污染关系,研究区土壤重金属总体污染程度较轻。 相似文献