夏尔希里地区土壤重金属特征及空间变异分析

Characteristics and spatial variability analysis of soil heavy metals in Xarxili Area

以夏尔西里地区为研究区,对土壤中As、Zn、Hg、Pb等4种重金属的含量特征和空间分异特征进行研究,并采用单因子污染指数法、内罗梅综合污染指数法、克里格插值法对研究区土壤重金属污染状况和分布特征进行了分析,结果表明：研究区4种重金属含量为：Zn〉As〉Pb〉Hg,Hg属于强变异性,其它3种重金属和有机质均属于中等变异强度;相关性分析结果显示：Zn和Pb呈现显著的正相关,As与Hg、Pb均表现出显著的负相关,有机质和Pb、As、Zn、Hg呈现出弱相关性;重金属含量空间分异特征整体表现为绿洲区〉荒漠区〉山地区;重金属污染评价结果为：Pb和Zn污染指数介于1～2之间,属于轻污染,Hg和As污染指数介于2～3之间,属于中度污染。

Xarxili Nature Reserve is located in the southern piedmont of the Alataw Mountain in Xinjiang,China,its western part borders on the Republic of Kazakhastan,and its area is 314 km2,the Xarxili Nature Reserve returned to China in 1999. Due to its nature of less artificial interference,Xarxili Nature Reserve is seen as an ideal place to study environmental background. In this paper,aiming at assessing heavy metals pollution and spatial distribution characteristics of Xiaerxili Nature Reserve（oasis,desert and mountain forest area）,the contents of four heavy metals（As,Zn,Hg and Pb）in 71 soil samples from these regions were determined,in combination with single factor pollution index,Nemerow integrated index,and Kriging interpolation methods. The results show that contents of the heavy metals is Zn〉 As〉 Pb〉 Hg in the Reserve. Hg exhibits strong spatial-related variability,while the other three heavy metals and organic matter present moderate variation. Correlation analysis found a significant positive correlation between Zn and Pb,significant negative correlation between As and Hg（and Pb）,a weak correlation between organic matter and each metal studied. The spatial distributions of heavy metal contents are oasis areadesert areamountain area as an ensemble. Assessment of heavy metal pollution indicates light pollution for Pb and Zn with pollution indexes ranging from 1 to 2,moderate pollution for Hg and As ranging from 2 to 3. This paper features macroscopical comparison of the effects on spatial distribution of heavy metals in different regions,which are distinguished by natural factors or human factors,it is also noted that one deliberately chosen region,with the heavy metals remaining naturally intact,ensures excellent comparability of the study. This paper provides reference to the exploration of soil remediation in arid areas.