Study And Application Of The Key Technologies Of The Geoportal-based Basin Water Environmental Information Sharing Platform

In recent years, with the development of society and economy and the increase of human activities, pollution incidents occurred in China more and more frequently, especially the basin water environmental pollution, what people pay more attention to and caused a high degree of attention of the relevant state departments. It’s crucial to control and governance the basin water environmental pollution for the socio-economic development and human life safety. How to use the basin water resources scientifically and rationally to assess, monitor and early warn the risk of basin water environment is extremely important, and at the same time, it can provide quick and accurate decisions based on controlling basin water pollution for the state environmental protection departments.As a basis for basin water environmental risk assessment, monitoring and early warning, the basin water environmental information sharing platform provides data support for the application system distributed in different regions and different sectors. According to analyzing the characteristics and current distribution of the basin water environmental data, this paper proposes the basin water environmental information sharing model based on the Geoportal, uses the SOA architecture thought and with ArcGIS Server as a platform, Geoportal extension component as the basis, hierarchical design and develop the sharing platform, and at the same time, this paper in-depth studies three key technologies—metadata technology, directory service technology and the technology of integrating the information resources with Geoportal, and all these provide technical supports for the Geoportal-based basin water environmental information sharing platform construction.The main research contents and results are as follows:(1) Starting from the present situation of the study on basin water environmental information sharing, after analyzing the research background as the characteristics, current distribution and sharing needs of the basin water environmental data, the basin water environmental information sharing model based on the Geoportal is proposed.(2)Metadata technology is described in detail, and the construction model "module—metadata entities—metadata element" is defined. In addition, with the environmental information core metadata standard as the basis, this paper researches the metadata extension principle and extension methods, and the basin water environmental information metadata is classified, finally, the metadata database is established according to the actual application needs.(3)This paper in-depth studies the directory service technology, and mainly introduced the LDAP directory service what to store the metadata of the heterogeneous data sources, and next, the catalog model, catalog view, catalog data and catalog schema are designed, finally, database metadata is stored in the directory information database constituted.(4)To study the technology of integrating the information resources with Geoportal, and study the technology in three levels—interface, functions and data with the Geoportal API, module components and the standards supported, so the problems of low coupling and loosely business are solved.(5)According to the SOA architecture ideology and hierarchical design model, this paper proposes the overall design program of the basin water environmental information sharing platform, including the overall frame design and the overall functional design. Also, in this paper, the actual technical route for developing is designed, and in the last, parts of functional modules of the basin water environmental information sharing platform are shown.