北京市土壤重金属潜在风险预警管理研究

区域土壤重金属的潜在环境质量风险预警研究是区域土壤重金属管理研究的热点之一。以北京市为研究区,在镇域尺度上建立土壤重金属输入-输出通量模型和重金属年累积率模型,计算2006年北京市各乡镇Cr、Ni、Zn、Hg、Cu、As、Cd、Pb八种重金属的通量和累积量。以2006年作为基期年,采用指示克里格法预测北京市未来30 a土壤重金属含量变化趋势和环境质量风险。研究表明,在当前发展趋势下,未来30a北京市Pb、Cr和Ni土壤环境污染风险较小,含量均处于国家土壤环境质量二级标准以下;Cu、As和Zn最高达到中警级别,Hg和Cd的污染风险变异较大,各预警级别均有出现,但概率大小不等,其中Cd的环境风险最为严重,高风险区部分位于北京市东部,呈带状分布;Hg的环境高风险区域随城市的扩张而蔓延。采用地统计学与区域物质流通量模型结合的方法,可为区域土壤重金属的宏观预警研究提供技术支撑。

Early warning of heavy metals potential risk governance in Beijing

Early warning of heavy metal potential risk for regional environment quality management is one of the hot topics of the management of land environmental risks. With Beijing cited as a research area, a town-scale input-output flux and heavy metals accumulation rate model was established to calculate fluxes and accumulation of Cr, Ni, Zn, Hg, Cu, As, Cd and Pb in 2006, using the cringing method by taking into account the datasets cited from the literatures, statistical yearbooks and field survey in 2006. With 2006 set as a benchmark year, prediction was made of variation trend and environmental quality risk for the future 30 years. Results show that based on the current situation, soil environment risk will remain quite low for Pb, Cr, and Ni in the next 30 years, and their concentrations will linger below Grade II criteria of the national standard for soil environmental quality, Cu, As and Zn will possibly reach medium in alarm level, while Hg and Cd will vary greatly and all the warning levels will appear and vary in probability;Among the 8 heavy metal elements, Cd will be highest in environmental risk and some of the risk will mainly spread in the east; The high Hg risk areas will expand with the urban does. The use of the Geostatistics technology coupled with the regional flux model could provide an excellent technical tool for macro-scaled early-warning of regional soil heavy metals pollution.