Based on analysis of the soil samples collected in Southeast Zunyi from 2003 to 2008, an early warning model and a deterioration speed model for heavy metal contamination of agricultural soil is worked out with the modified analytic hierarchy process and time series technique. The second exponential smoothing method is used to forecast index of soil pollution and speed of soil deterioration. Results show that in 37 years beginning from 2008, heavy metal contents in the soil will be to the grade of slight contamination in the region if no any protective measures taken on purpose. Verification reveals that the predicted values taffy well with the measured, with an average relative error being ＜ 6％. The models are fit for agricultural areas where no serious accidents of heavy metal pollution have ever occurred and the heavy metal contents in the soil are relatively stable.%于2003-2008年对遵义东南部地区耕作区的土壤重金属含量进行检测,选取Cd、Pb、Cr、Hg、As 5种重金属,将改进型层次分析法和时间序列法相结合建立农业土壤重金属污染趋势预警模型和恶化速度预警模型,采用二次指数平滑法预测未来农业土壤重金属综合污染指数及恶化速度.结果表明,如无人为保护措施,自2008年起再过37 a该地区土壤重金属含量将达轻度污染.校验结果表明预测值与实测值较为符合,平均相对误差小于6%.该模型适用于未受过人为大量污染的、重金属含量变化较为稳定的农业地区.
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