雄安新区土壤地球化学特征及控制因素

研究土壤地球化学分布模式和驱动机制,是区域生态环境评价、土地资源合理开发的重要支撑。本文利用空间分析和多元统计分析方法,利用土壤地球化学调查数据,探讨雄安新区土壤地球化学分布模式及成因。结果表明：研究区土壤元素普遍富集,Cd、Cu、Pb、Zn、Se和Corg呈明显富集,平均值约为河北平原背景值1.16~1.44倍。大部分土壤地球化学元素分布模式受成土母质、地貌类型、风化淋溶作用等控制,高值区主要分布在冲湖积平原区;淋滤径流、蒸发浓缩、工农业生产、土地利用等是影响土壤地球化学分布的重要因素;重金属和养分元素受人为因素影响明显。因子分析共提取8个主因子,F1因子由造岩元素和微量元素组成,代表自然成壤作用;F2因子由重金属元素组成,与污水灌溉、冶炼制造等活动相关;F3因子由CaO、TC、Ge、Ti、SiO₂组成,主要与硅酸盐矿物风化、次生碳酸盐形成等成土过程相关;F4因子由Cl、S、pH组成,主要受淋滤径流、蒸发浓缩作用影响;F5因子由土壤养分元素和植物营养元素组成,主要受农业种植影响;F6因子由B和Sr组成,主要与黏性土壤的物理化学吸附作用有关;F7因子由卤族元素I和Br组成,主要与地表径流过程相关;F8因子由Hg组成,与当地工业生产以及城镇生活排放活动相关。研究结果清晰地反映了研究区土壤元素地球化学分布模式和主控因素,可为区域规划建设、资源环境评价和合理开发保护提供基础资料和重要依据。

Geochemical characteristics of soil elements and its driving mechanisms in the Xiong'an New Area,China

Conducting the soil geochemical survey, and accessing the distribution and driving mechanisms of soil geochemical parameters are of great significance for eco-environment condition evaluation and the land resources management. Based on the soil geochemical survey in the Xiong'an New Area, a combination of spatial analysis and multivariate statistical analysis was used to study the spatial distribution patterns of soil elements, and discuss the driving mechanisms of these elements. The result showed that most elements were enriched in soils of the study area compared with their background values of Hebei plain. The concentrations of Cd, Cu, Pb, Zn, Se, and Corg in soils were 1.16-1.44 times higher than their background values of Hebei plain. Most elements were principally concentrated in the alluvial lacustrine plain, which was mainly determined by the parent materials, landform types, and weathering and leaching processes. Anthropogenic factors such as land utilization and industrial and agricultural activities significantly influenced natural evolution of heavy metals and nutrients elements in soils in the study area. Eight factors were extracted to represent different driving mechanisms of soil elements distribution. F1, mainly consisting of lithosphere and siderophile elements and rare earth elements, represented pedogenesis process. F2, composed of heavy metal elements, was associated with anthropogenic activities such as sewage irrigation and industrial production. F3, made up of CaO, TC, Ge, Ti, and SiO₂, was related with the processes of silicate mineral weathering and secondary carbonate formation. F4, comprised of Cl, S, and pH, had a close relationship with the processes of leaching and surface runoff, and evaporation and concentration. Meanwhile, land utilization also exerted an influence on the distribution of these elements. F5, composed of soil nutrients elements, was mainly affected by anthropogenic activities such as land utilization and agricultural activities. F6, principally including B and Sr, illustrated the adsorption reactions with soil clays. F7, made up of I and Br, reflected surface runoff process. F8, including Hg, was correlated with anthropogenic emissions such as coal combustion and smelting activities. The result of this study clearly uncovered the geochemical characteristics of soil elements and its driving mechanisms in the Xiong'an New Area, which would provide valuable information for rational land resources utilization and environmental protection in the study area.