土壤学报2017，Vol.54Issue(1)：81-91,11.DOI:10.11766/trxb201603100033
基于GIS的农业土壤重金属风险评价研究*--以南京市八卦洲为例
GIS-Based Heavy Metals Risk Assessment of Agricultural Soils-A Case Study of Baguazhou,Nanjing
摘要
Abstract
Objective]Safety of agricultural producing areas has become an extensive concern. Heavy metal pollution of agricultural soils not only brings about adverse effects on the soil ecosystem,but also is closely related to food safety and potential health hazard. How to assessment the risk of heavy metals pollution of agricultural soils is of some practical and far-reaching significance. Therefore,it is a very urgent task to investigate the status of heavy metals in agricultural soils and assess the risk with a variety of assessment methods. The findings in this study may help decision-makers select appropriate assessment methods for rational assessment and zoning of the agricultural producing area and remedy contaminated soils scientifically.[Method]Taking the agricultural soil in Baguazhou Town of Nanjing as an example,this study focused on the five heavy metal elements,i.e. As,Cd,Cr,Hg and Pb,that are relatively more harmful than the others to the human body and analyzed the soil samples collected from the surface soil layer(0~20cm)in 2015. In October 2015,the Chinese Ministry of Agriculture promulgated the“National technical regulations for safety assessment of heavy metals in agricultural producing areas”(Standard Methods for Producing Areas), which has modified the criteria of some relevant elements and specified the use of a new method called the maximum single factor index method for assessing integrated risk of heavy metals in agricultural soils. It is necessary to adopt the specific standard and method to do the assessment. The study used the Traditional Standard Method(T-SM)and the Standard Method for Producing Areas(PA-SM)to assess the risk of heavy metals in the study area and compared the two methods for differences. Furthermore,an Improved Geo-accumulation Comprehensive Index Method(IG-M)was created to assess the ecological risk of heavy metals in the study area. With the aid of GIS geostatistics,spatial distribution of different heavy metals risk levels was characterized. The inverse distance weighting interpolation method was used in this study.[Result]Results show that the average concentration of As,Cd,Cr,Hg and Pb was11.0,0.38,92.1,0.08 and 34.5 mg kg-1,respectively. All of them,except for Hg,were beyond their background values in Nanjing. The elements of Cd,Cr and Pb exceeded the criteria for soil quality to a varying extent,especially Cd,which should be paid more attention to. The use of PA-SM found that over 80% of arable land in Baguazhou was risk-free and Cd and Pb were the main factors that posed a low risk. Risk areas scattered across the southwest, south and east parts of Baguazhou,which may be associated with the distribution of large and medium factories and plants,while the use of T-SM displayed that only Cd exceeded the standard. The use of PA-SM revealed that the risks of Cd,Cr and Pb were relatively high due to human activities,while the use of the IG-M disclosed that the study area as a whole was good in ecology.[Conclusion]Generally speaking,the agricultural environment of Baguazhou was good,but the risk area in the south needs intensive monitoring and adoption of pollution control measures. T-SM and PA-SM can work together to identify risk-free region,but PA-SM can better evaluate and divide risk areas. Therefore,it is recommended to use PA-SM in conjunction with IG-M to assess risk levels,spatial distribution and ecological risk of the heavy metals in the agricultural soil of the region.关键词
农业土壤/重金属/风险评价/GISKey words
Agricultural soil/Heavy metals/Risk assessment/GIS分类
资源环境引用本文复制引用
宋金茜,朱权,姜小三,赵海燕,梁永红,罗永霞,王强,赵林丽..基于GIS的农业土壤重金属风险评价研究*--以南京市八卦洲为例[J].土壤学报,2017,54(1):81-91,11.基金项目
国家水体污染控制与治理科技重大专项（2012ZX07101-009）和江苏省农产品产地安全智慧管控系统项目（JSZC-G2015-039）共同资助 Supported by the National water pollution control and management technology major projects（2012ZX07101-009）and Intelligent management system for safety of agricultural producing area of Jiangsu Province，China （）
