Organization And Extraction Of Internet Geographical Information And Its Application In Agricultural Information

As the increasing development of "three S" technologies and network technology, how users can quickly and correctly obtain the needed information, has become one of key issues of geographical information towards public information services, which make research on internet geographical information organization and extraction been paid more and more attention.In the light of three information classifications: syntax information, pragmatics information and semantics information, correspondingly geographical information organization and extraction can be divided into three levels, namely, syntax-level, pragmatics-level and semantics-level. However, up to now, geographical information organization and extraction mainly focuses on the syntax-level information organization and extraction, the needs of more advanced level extraction to masses of geographical information of users can not been satisfied. This paper tries to study methods of advanced geographical information organization and extraction, based on research of geographical information classification and codes, geographical information metadata and spatio-temporal data mining, facing to users, masses geographical information, full-aspect geographical information expression and more advanced geographical information organization and extraction under the condition of network. Multi-demension geographical information classification and codes, five-level geographical information metadata and hypergraph-based spatio-temporal data mining are put forward. Moreover, user-oriented agricultural geographical information classification and codes, five-level geographical information metadata management system are designed and implemented in the case of distributed Chinese agricultural information metadata management sysytem to test methods put forward in the paper.The main work of the paper concertrates on the following four parts: 1) Initiatively bring forward multi-level geographical information classification and codes, space and time scale are brought intogeographical information classification and code system, embodys spaceand time characteristics of geographical information and expresses geographical information integerally. The characteristics and evaluation criterion of classification of geographical information on the network are summarized and the classification and code system of network user-oriented multi-level agricultural geographical information is established.2) Facing to more advanced and masses of geographical information extraction, current geographical information metadata content system is extended. In the peper, five-level geographical information metadata content system and their UMLmodels are designed, including data-level metadata, database-level metadata, model-level metadata, subsystem-level metadata and distributed system-level metadata. Five-level geographical infonnation metadata management system are schemed out3) Developing spatio-temporal data mining system structure and summing up knowledge types mined from sptio-teinporal databases. The method of projecting relation-object database to hypergraph model and the method of attribute-oriented hypergraph-based sptio-temporal data mining are studied. A mode of Metadata-based hypergraph-based sptio-temporal data mining is designed.4) Implementing Multi-demension geographical information classification and codes, build up network user-oriented agricultural geographical information classification and codes bases. The paper takes distributed Chinese agricultural information metadata management sysytem as example, in which five-level geographical information metadata content system and its management system model are used.