在大规模的土壤取样调查和分析基础上,以北京市为例,建立了土壤重金属信息系统(SHMIS)。该信息系统由土壤重金属数据库(SHMD)及其数据库管理系统(SHMMIS)两大部分组成。该信息系统的资料覆盖北京市18个区县,共800组土壤重金属和近400组蔬菜重金属等相关信息。土壤重金属数据库由6个表相互关联而组成,其中采样区的基本地理属性、样品重金属含量、样点与周围地物空间关系、农作物组成等不同的分类信息分别列在不同的表中。用户通过SHMMIS可对数据进行查询、分类和统计,获得需要的数据。该信息系统的建立既使得采样工作能够与空间分析相结合,对重金属含量变异趋势大的区域进行加密布点,提高每个样点的信息量;数据库同时存储土壤及其所产蔬菜等农作物的重金属含量,为蔬菜重金属污染风险分析、区域土壤环境质量评价等研究、决策管理提供一个数据平台。

The progress and advancement in Soil Information System (SIS) are reviewed in the paper. The status of heavy metal contamination in surface soil showed that it was necessary to develop soil databases of heavy metals as a new special kind of SIS. Such SIS was named Soil Heavy Metals Information System (SHMIS). It was composed of Soil Heavy Metal Database (SHMD) and Soil Heavy Metal Management Information System (SHM MIS). The SHMIS could be used to investigate the concentrations of heavy metals in soils, and its spatial distribution and spatio temporal variation. The paper describes the structures and functions of the database. All kinds of useful data were classified into forty two fields in six tables,which were related with a key field named SID (Soil samples ID).And the data integrity can be checked and controlled with DBMS. These data stored information, e.g., basic geographic attributes around sampling areas,concentrations of heavy metals of soil samples,spatial relationships between sampling areas and geographic conditions, the growth status of sampling areas, etc. A kind of MIS named SHM MIS was developed to manage the information. Under the circumstances of SHM MIS, data could be browsed, edited, analyzed, and queried according to the identification of users. Assisted with this database, the sampling procedure would process step by step, i.e. , followed stage of sampling would be directed with spatial analysis based on the data management of database so that the information of sampling could reveal the spatial distribution of heavy metals in soil with proper density of sampling. Furthermore, this database can support many other researches about heavy metals of soil, such as risk evaluation.