贵阳市土壤地球化学背景与生态环境分析

Geochemical Background and Ecologic Environment of Soil in Guiyang City,Guizhou Province,China

通过1∶250 000多目标区域地球化学调查,获得了贵阳市及邻区表、深层土壤中54项化学指标的地球化学背景值、基准值等参数。研究区总体土壤环境呈中偏酸性,对生态环境影响较大。土壤化学物质组成丰富,地球化学背景分布不均匀。除活动性强的化学组分对成土母质有分异外,多数化学组分对成土母质继承性显著。表层土壤有机碳、全碳、硫、氮、硒、氟和汞、镉、砷等的地球化学背景值显著高于深层土壤和我国其它城市地球化学基准值。前者适宜发展生态富硒特色农业,后者表明土壤环境安全形势严峻。土壤地球化学背景为生态环境评价和其它相关学科研究提供了科学基础,由此提出生态环境保护和利用建议。

Based on 1∶250,000multi-purpose regional geochemical survey,up and deep layer soils of Guiyang City and its adjacent area were analyzed for their geochemical compositions.Results show that the pH of the soils is neutral to slightly acid which has significant effect on the eco-environment.Many elements of the soils are enriched and distributed heterogeneously.Unlike mobile elements,immobile elements are mainly inherited from its parental soil.The Corg,total C,S,N,Se,and F are generally higher enriched in up layer soil than those of deep layer soil and other city soil,indicating that the up layer soil of Guiyang City is suitable for developing ecological selenium-rich characteristic agriculture.Meanwhile,Hg,Cd,As and other heavy metal elements are also highly enriched in the up layer soil,implying that the soil environmental safety needs to be concerned.