三峡库区小江流域消落带土壤Zn各形态有效性及缓变型地球化学灾害分析

通过分析三峡库区小江流域消落带土壤Zn全量、形态及有效性，并基于缓变型地球化学灾害数学模型，研究了区域内土壤Zn的缓变型地球化学灾害特征。结果表明:研究区域内全量Zn的平均值为123.88 mg/kg，高于国家土壤环境质量一级标准，但明显低于二级标准。Zn的酸溶态、可还原态、可氧化态、残渣态平均值占全量平均值的百分比分别为2.93%、4.42%、8.71%和83.94%，有效态占4.51%。酸溶态、可还原态、可氧化态与有效态相关性密切；可还原态和可氧化态含量对有效态含量贡献较大。在小江流域消落带的土壤中Zn具有缓变型地球化学灾害特征，土壤中Zn有可释放总量向次生相态释放转化的趋势，其缓变型地球化学灾害临界值为130.67 mg/kg，32%的土壤样品具有爆发Zn缓变型地球化学灾害的可能性。

Effectiveness and Delayed Geochemical Hazard Analysis of Various Forms of Soil Zn Element in Water-level-fluctuating Zones in Xiaojiang Watershed of Three Gorges Reservoir Area

The total content and speciation,effectiveness of Zn element in the water-level-fluctuating zones in Xiaojiang Watershed of Three Gorges Reservoir Area had been analyzed.And a study on the delayed geochemical hazard character of Zn element in regional area soil had been carried out based on the delayed geochemical hazard mathematic model.The results shows: the average amount of total content of Zn element in the study area is 123.88 mg/kg,which is higher than primary state soil environment quality standards...