不同数据情境的耕地土壤重金属污染监测点位布设方法

利用基础数据指导监测点位布设成为近年来的研究热点。以北京顺义区重金属Cd污染监测为例,研究耕地土壤重金属污染监测在不同数据情境下的点位布设方法。首先划分了耕地土壤重金属污染监测的基础数据情境,其次探讨了点位布设方法的特点及适用数据情境,最后利用均匀变异指数和偏离指数评价点位布设的均匀性。研究结果表明：（1）存在“无历史,无辅助”、“无历史,有辅助”、“有历史,无辅助”、“有历史,有辅助”、“历史充足”5种基础数据情境,并分别推荐了系统/随机采样布局、无偏采样布局、加密采样布局、加密/无偏采样布局、去冗精化布点策略。（2）顺义区西部属于“无历史,无辅助”数据情境,采用系统采样布局;顺义区东部属于“历史充足”数据情境,采用去冗精化处理。顺义区的均匀变异指数由原始0.546下降到0.490,尤其是顺义区东部均匀变异指数下降到0.468,且偏离指数小于原始样本点布局,验证了不同数据情境的耕地土壤重金属污染监测点位布设方法的可操作性和可行性。该研究可为耕地土壤重金属污染监测点位布设方法的选择提供理论基础和技术支撑。

Monitoring Site Layout Method for Heavy Metal Pollution of Cultivated Soil Under Different Data Scenarios

Guiding the layout of monitoring sites using basic data has become a research hotspot in recent years. Taking the monitoring of heavy metal Cd pollution in Shunyi District of Beijing as an example, monitoring site layout method for heavy metal pollution of cultivated soil under different data scenarios was developed in this study. Firstly, the basic data scenarios of heavy metal pollution monitoring in cultivated soil were divided. Secondly, the characteristics and applicable data situations of the monitoring site layout method were discussed. Finally, the even variation index and deviation index were adopted to evaluate the uniformity of monitoring sites. The research results showed that: (1) five basic data scenarios were identified based on historical and auxiliary data, namely no historical and auxiliary data, only auxiliary data, only historical data, historical and auxiliary data, and sufficiently historical data; and system/random sampling layout, unbiased sampling layout, encrypted sampling layout, encrypted/unbiased sampling layout and data refinement layout strategies were correspondingly recommended; (2) no historical and auxiliary data were in the western Shunyi District and the corresponding system sampling layout was adopted, while sufficiently historical data were in the eastern Shunyi District and the corresponding data refinement layout was used. Moreover, the even variation index of Shunyi District decreased from 0.546 to 0.490, especially to 0.468 in the eastern Shunyi District, and the deviation index was smaller than the original sampling site layout. It is confirmed that the monitoring site layout method for heavy metal pollution of cultivated soil under different data scenarios has operability and feasibility. This study can provide a theoretical basis and technical support for the sampling site layout method of heavy metal pollution monitoring in cultivated soil.