Knowledge Service Oriented Disaster Metadata Structure Design And Implementation

Disaster data is comprehensive and decentralized.Because of the means of collecting,storing and managing disaster data are different,the disaster data lacks the unified standard format of metadata,which causes difficulties in data integration,information extraction and knowledge service of different disaster data.In order to meet the international and domestic knowledge service demand of disaster prevention and reduction,this paper begins with the disaster metadata standard,the bottleneck problem.Based on the characteristics of disaster data,the structure and content of disaster metadata standard are analyzed and designed,which is suitable for knowledge discovery and service,and the disaster metadata catalogue service tools and metadata management prototype system are designed and implemented,which lays a foundation for the knowledge service of disaster data.The main research of this paper is as follows:(1)The structure analysis and common information extraction of disaster related metadata standards at domestic and foreign.According to the basic definitions of metadata and metadata standards,the definition of disaster metadata and disaster metadata standard are summarized.A contrastive analysis of metadata structure of disasters is made from the three aspects,the comprehensive disaster metadata standard,the single disaster metadata standard and the metadata standard in the field of related information,and the common metadata subsets and corresponding elements are extracted,which provides reference for the subsequent development of disaster metadata standards.(2)Structure and content of disaster metadata standard design.A disaster metadata structure framework is designed,which consists of 10 subsets,such as metadata entitites information,identification information,content information,data quality information,constraint information,and distribution information.The paper designs disaster metadata standards from two levels of disaster core metadata and disaster complete metadata.The disaster metadata standard specifically includes 39 entities and 114 elements,among which there are 30 core metadata elements.The UML diagrams and data dictionaries are used to describe disaster metadata and generate XML Schema files.(3)Design and development of disaster metadata catalogue service tools.Disaster metadata server and pycsw metadata server are deployed respectively,and the communication between the two servers is realized through the mapping of the disaster metadata standard and the metadata standard supported by pycsw.As the sub center node of pycsw,the disaster metadata server realizes the publishing and harvesting of metadata.And the disaster metadata is published in three ways: disaster core metadata,post-mapped ISO 19115 and Dublin Core metadata.(4)The construction of disaster metadata database and the implementation of metadata management prototype system.According to the designed disaster metadata standard and the classification of disaster data,disaster metadata repository is constructed.Based on metadata catalog service tools and metadata repository,design and implement disaster metadata management prototype system,and users can manage disaster metadata and retrieve metadata online.