哈尔滨市城市土壤重金属空间分布特征及相关分析

利用GIS软件和地统计学方法分析哈尔滨市土壤重金属镉、铅、铜、锌(Cd、Pb、Cu、Zn)元素在市区内的含量分布、空间异质性以及元素之间的相互关系。样品为2008年10月在哈尔滨市区内采集的53个土样,采样面积为7 086 km2。分析结果表明,土壤重金属元素Cd、Pb、Cu、Zn块金值与基台值之比C0/(C0+C)都在25%～75%之间,属于中等的空间相关性;Cu和Zn、Cd都存在极显著正相关,Zn不仅与Cu、Cd存在着极显著正相关还与Pb存在着极显著正相关。Cd元素分布表现出明显的阶梯状,由道外区向道里区逐渐降低,道外区域整体偏高含量在0.22～0.26 mg.kg-1之间,属于轻污染级(0.2～0.4 mg.kg-1);Pb元素平均含量为41.1 mg.kg-1,在轻污染级别以内(35～70 mg.kg-1),其中较高区域是南岗区和平房区;Cu元素的分布特征是东北部的道外区高于整个市区的平均值(34.54 mg.kg-1),而南部的南岗区、道里区、平房区、阿城地区低于平均值(34.54 mg.kg-1);Zn元素平均含量为108.6 mg.kg-1,略高于Zn的警戒含量100 mg.kg-1,其中道外区属于中污染级(200～300 mg.kg-1),含量在239.5～287.4 mg.kg-1。

Study on spatial variability of soil heavy metal in Harbin building area

Geostatistics method and Geographic information systems(GIS) were introduced to study the spatial distribution of soil heavy metals(Cd,Pb,Cu,and Zn),the differences and correlation among different soil heavy metals in different function areas of Harbin city,Heilongjiang Province.A total of 53 samples covering 7 086 km2 were collected in the Harbin City in Oct.2008.The results were as follows: the ratios between C0 and C0+C of Cd,Pb,Cu,Zn were all between 25% and 75%,which indicated the medium spatial correlation;there were significant positive correlation among Cu and Zn,Gd;there are also significant positive correlation between Zn and Cu,Gd,Pb;the distribution of Cd showed obvious ladderlike way,the content of Cd descends from Daowai district to Daoli district,the content of Cd was between 0.22-0.26 mg.kg-1,belonging to the light pollution grade;the average content of Pb was 41.1 mg.kg-1,within light pollution grade(35-70 mg.kg-1),and the higher area was Nangang and Pingfang districts;Cu content of Daowai district from northeast was higher the average of the whole city,and Nangang,Daoli,Pingfang and Acheng districts were lower than the average content(34.54 mg.kg-1);the average content of Zn was 108.6 mg.kg-1,little higher than watching content(100 mg.kg-1),and Daowai was between 239.5 mg.kg-1 and 287.4 mg.kg-1 belonging to medium pollution grade(200-300 mg.kg-1).