Abstract: 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 area > desert area > mountain 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.

Key words: Xarxili area, soil heavy metal, correlation analysis, analysis of pollution index, spatial variability