成都平原土壤中砷的空间分布及污染评价

Spatial Distribution and Pollution Assessment of Soil Arsenic in the Chengdu Plain

在成都平原核心区（14县区）采集土壤样品197个，室内分析和数理统计表明：As含量在3．00—20．57mg kg^-1之间，平均为10．41mg kg^-1；各县区差异较大，广汉、龙泉和德阳旌阳区较背景值明显增加，分别增加了2．4、1．4和1．0倍。Kriging插值结果表明：As含量空间分布规律较明显，从西北到东南呈现递增趋势。污染评价结果为：仅有15．74％的样点超过《土壤环境质量标准》中的一级标准，一个样点超过二级标准；人类活动对As含量的影响级别为1-3级，以1级为主，属无污染到中污染的过渡级。

Soil samples （197） were collected from the main areas （14 counties） of the Chengdu plain and the spatial distribution and pollution assessment of soil arsenic in the plain were investigated. The result, based on the methods of chemical analysis and mathematical statistics, showed that the range of soil arsenic content was from 3.00 to 20. 57 mg/kg,and the average value was 10.41mg/kg. The content of different counties varied significantly, The arsenic content increased progressively from northwest to the southeast spatially. The results of pollution assessment indicated that As content in only 15.74% samples surpassed the standard of grade 1 level in the Soil Environment Quality Standard, and only 1 sample surpassed grade 2. The extent of influence by human activity was from grade 1 to grade 3, but mostly by grade 1 level, which was the transition level of pollution.