2004—2013年石家庄市土壤铅元素分布变化

Spatial Distribution Change of Topsoil Pb between 2004 and 2013 in Shijiazhuang City, China

【目的】了解石家庄市区及周边土壤中的铅元素(Pb)在2004年至2013年10年内的空间分布变化情况。【方法】分别在2004和2013年,大密度采集石家庄市及周边区县表层(0~20 cm)土壤样品,测定Pb含量;统计对比10年间Pb元素的基本参数数据;利用ArcGIS 9.3软件进行空间分析,对比2个年份Pb的空间分布变化;利用地累积指数法评价2个年份的Pb污染状况。【结果】(1) 2004和2013年石家庄市区及周边区县土壤Pb含量均值变化较小,分别为23.04和24.31 mg/kg,但最大值和变异系数变化较大,最大值从59.50mg/kg增长到82.50 mg/kg,变异系数从20.23%增长到23.45%。(2)从2004到2013年,Pb的低含量土壤面积在缩小,高含量区域增加。显著低值区和低值区面积从545.10 km^2减少到388.08 km^2,高值区和显著高值区面积从545.10 km^2增长到594.00 km^2。(3)研究区Pb污染状况相对较轻但有所发展,2004年主要在石家庄市区存在轻度污染,但2013年时,正定新区出现了少量的中度污染,轻度污染在郊县地区也有所扩大。【结论】石家庄市区及周边土壤Pb的分布与当地主要经济建设活动有密切联系,Pb分布在时间序列上的变化反映了石家庄10年间的经济社会变化。

[Purpose]To understand the spatial distribution change of topsoil Pb in Shijiazhuang urban and suburb between 2004 and 2013. [Method]Soil samples were systematic collected at high density from the surface layer(0-20 cm) in Shijiazhuang urban and surrounding counties. The basic parameter data of Pb were compared between 2004 and 2013. Using spatial analysis module of ArcGIS 9.3, the spatial distribution of annual Pb-content were compared, and the Pb pollution status was evaluated by the ground accumulation index method during 2004-2013.[Results](1) The Pb average content changed slightly from 2004 to 2013. The average Pb-content of 2004 and 2013 was23.04 and 24.31 mg/kg, respectively. However, the maximum value and coefficient of variation changed greatly, the maximum value increased from 59.50 mg/kg to 82.50 mg/kg, and the coefficient of variation increased from 20.23 % to 23.45 %.(2) From 2004 to 2013, the low Pb-content soil area decreased, meanwhile the high-content area increased. The areas of very low value and low value decreased from 545.10 km^2 to 388.08 km^2, and the areas of high value and very high value increased from 545.10 km^2 to 594.00 km^2.(3) In study area, Pb pollution was relatively light, but the pollution situation was gradually developing. In 2004, the pollution zone was mainly in urban area, and pollution level was slight. In 2013, a small amount of moderate pollution appeared in Zhengding New District, and the light pollution expanded in suburban counties.[Conclusion]The distribution of Pb was closely related to the main economic construction activities in the area. The changes of Pb-content distribution reflect the economic and social changes in Shijiazhuang City during 2004-2013.