Research On Soil Heavy Metal Pollution Assessment Resources Integration Based On Metadata Matching

According to “The Soil Pollution Prevention and Control Action Plan”,the soil environmental quality survey was launched nationwide,and a soil environmental quality monitoring network of all counties(cities,districts)will be constructed at the same time.Massive soil environmental monitoring data and the current trend of informatization have greatly promoted the development of soil environmental big data.How to deal with the challenges brought by the big data of soil environment,accelerate the process of using soil environmental big data for agro-ecological environmental protection,soil pollution prevention and land use planning,and improve the level of soil environmental information,has become a major research hotspot.This paper carried out research based on the the national major research and development project “Agricultural Non-point Source and Heavy Metal Pollution Management Decision System Platform”,Taking the “Evaluation of Soil Heavy Metal Pollution by Applying Soil Environment Big Data” as the entry point.Through the research on the demand of relevant units,this paper has in-depth understanding of the specific resources and processes such as data,models and systems applied in the actual soil heavy metal evaluation process.The study found that the soil environmental data collected by various fields and departments has relatively scattered data collection,storage and use methods,multi-source heterogeneity of data,large data application restrictions,and low data sharing and utilization efficiency.The soil heavy metal pollution assessment tasks performed by the units are different.The relevant data and models used have commonalities and heterogeneities.When performing tasks for different decision scenarios,the steps are cumbersome and the resource utilization efficiency is low.This paper carries out corresponding research on the above two issues.Analyzed the specific needs of data,models and other resources when the business segments conducting the soil heavy metal pollution assessment business.Expanded national environmental data metadata standards,and conducted research on the establishment and extension of the soil heavy metal pollution metadata standard.Constructed a soil heavy metal resource integration framework based on meta-database.Designed an abstract processing chain for soil heavy metal pollution assessment process,and conducted research on the metadata matching and binding mechanism of soil heavy metal pollution resources based on metadata.Constructing a heavy metal pollution assessment workflow system based on Windows Workflow Foundation(WWF).Finally,achieved the soil heavy metal pollution resource integration and process automation based on metadata and workflow.The main research contents and conclusions of this paper are as follows:(1)Through the characteristic analysis of soil heavy metal pollution resources,the metadata standard for soil heavy metal pollution assessment that relying on national standards is constructed.The research on classified and stratified resource storage schemes realizes the unification of data access methods for multi-source heterogeneous soil heavy metal pollution assessment resources.This paper constructed a resource center for soil heavy metal pollution assessment with metadata as a resource index,physical classification,tiered storage,and logically unified organization.(2)The abstract processing chain model of soil heavy metal pollution assessment is designed,which realizes the separation of workflow abstraction layer and instance layer,improves the sharing,multiplexing and reconstruction capabilities of processing models,and enhances the scalability of workflow system.At the same time,the abstract processing chain model of the corresponding pollution assessment business is constructed,and the actual assessment process is transformed into an abstract processing chain that can be understood and processed by the computer.Realize the instantiation of data and processing nodes in the abstract processing chain based on the open workflow development platform Windows Workflow Foundation.(3)This paper use metadata to describe soil heavy metal pollution assessment resources,and use workflow technology to encapsulate it.Through the research of metadata-based workflow resource dynamic matching technology,the organic integration between meta-database,resource center and workflow system is realized.“Trinity” aims to cope with the megatrend of vigorous development of soil environment big data,and to face the increasingly complex massive pollution assessment task,and finally realize the integrated application of multi-source heterogeneous soil heavy metal pollution assessment resources for(semi)automatic soil heavy metal pollution assessment process.