新疆焉耆县耕地土壤重金属的空间分布及来源解析

Spatial Distribution and Source Identification of Heavy Metals in Farmland Soils of Yanqi County,Xinjiang

在新疆焉耆县采集53个耕地土壤样品,测定其中As、Cd、Cr、Cu、Mn、Ni、Pb和Zn的质量比,基于GIS技术研究其空间分布格局,运用多元统计分析法区分其主要来源。结果表明:焉耆县耕地土壤中Cd、Cr、Ni、Pb和Zn的质量比平均值分别超过新疆灌耕土背景值的0.50、0.40、0.33、1.63和3.92倍;在研究区内As、Cd、Pb质量比呈现由北向南逐渐升高趋势,Cr、Cu、Zn质量比呈现由北向南降低趋势,Mn和Ni质量比出现西部高值区;耕地土壤中As、Cd、Ni和Pb的来源主要受人类活动的影响,Cu和Mn的来源主要受土壤地球化学作用的控制,Cr和Zn的来源可能受人为污染与自然因素共同控制。

A total of 53 farmland soil samples were collected from Yanqi County,Xinjiang,and the mass ratio of eight elements（ As,Cd,Cr,Cu,Mn,Ni,Pb and Zn） were determined by standard methods. The spatial distribution patterns of these elements were analyzed based on GIS technology,and the main sources were distinguished by using multivariate statistical analysis method. Results showed that the average mass ratio of Cd,Cr,Ni,Pb and Zn exceeded by 0. 50,0. 40,0. 33,1. 63 and 3. 92 times of the background values of irrigation soil in Xinjiang,respectively. The mass ratio of As,Cd and Pb showed a gradually increasing trend from the northern part to the southern part in the study area,while Cr,Zn and Cu showed a decreasing trend. High-value districts of Mn and Ni were appeared in the western part. As,Cd,Ni and Pb in farmland soils were mainly affected by human activities,whereas Cu and Mn were mainly controlled by soil geochemistry characteristics.The main sources of Cr and Zn were affected by the interaction of human activities and natural factors.