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通过野外调查采样、室内分析与GIS制图相结合的综合研究方法,对河北省平原地区无公害蔬菜基地未来20年土壤镉的安全性进行预测预警。结果表明:河北省平原地区无公害蔬菜产地土壤中的镉,以大气干湿沉降为最主要的外源输入方式,其贡献率达66.36%。镉元素输出通量中以根菜类蔬菜为最高,叶菜类次之,果菜类蔬菜输出通量最低。通过对区内土壤镉累积量的预测,未来20年河北省平原地区无公害蔬菜基地土壤镉累积含量预测值仍符合现行国标(GB/T 18407.1—2001)要求,但20年后研究区内表层土壤中镉元素含量升幅明显,以每10年高于30%的速度累积,20年后是目前含量的1.6倍,累积量明显增加的区域集中在河北中东部地区,且露地蔬菜种植区土壤镉的净增量是设施蔬菜种植区3.7倍。说明河北省露地蔬菜土壤中由大气干湿沉降输入的镉元素对无公害蔬菜产地构成潜在威胁,需对现行生产加以严格的动态监测管理及污染源头控制,并针对预测含量高的区域进行不同蔬菜种植模式(露地或设施)的区域优化布局。
Through field investigation and sampling, indoor analysis and GIS mapping, a comprehensive research method was used to predict and predict the safety of soil Cd in the non-pollution vegetable base in Hebei plain in the next 20 years. The results showed that cadmium in the soils of pollution-free vegetables in Hebei plain was the most important exogenous input by atmospheric wetting and drying, and its contribution rate was 66.36%. Among the cadmium output fluxes, root vegetables ranked the highest, followed by leafy vegetables, and vegetables and vegetables ranked the lowest. By predicting the accumulation of soil Cd in the area, the predicted value of soil Cd accumulation in the non-pollution vegetable base of Hebei Province in the next 20 years still meets the requirements of the current national standard (GB / T 18407.1-2001). However, after 20 years, the surface layer The content of cadmium in soil increased significantly, with a rate of more than 30% every 10 years. After 20 years, the content of cadmium was 1.6 times that of the present. The area with a significant increase in accumulation concentrated in the central and eastern Hebei Province. The net increase is 3.7 times that of vegetable planting areas. The results showed that cadmium input by atmospheric wet-dry deposition in open-field vegetable soils in Hebei Province posed a potential threat to the origin of pollution-free vegetables. The current production was subject to strict dynamic monitoring and control and pollution source control. Different vegetables Regional optimization of planting patterns (open spaces or facilities).