Request Investigation And Analysis Of 1:50 000 Database Contents Refinement For National Fundamental GIS

At present, China has established a series of National Fundamental Geographical Information System (NFGIS) databases which provide a united and authoritative spatial carrier for GIS user community and play an important role in social development, economy and state safety. However, with the progress in national informatization, NFGIS has been confronted new requirements including its integration, refinement and updating from GIS users.NFGIS 1∶50 000 database is another great GIS project in China since the completion of 1:250 000 database. This thesis mainly concerns the requirement investigation and contents refinement of NFGIS 1:50 000 DLG database, which means to collect users' requirements on NFGIS database, such as data contents and attributes information. The survey was performed with questionnaires and the survey results have been summarized and analyzed further by adopting statistical method. Use's requirements on data contents and attributes information can be divided into three types-high, medium and low, so k-means clustering method is chosen. Three proposals are derived from the clustering results and proposal two seems more suitable for the reference of contents refinement of NFGIS 1∶50 000 DLG database. Furthermore, spatial analyses including feature contents completeness, logical consistency, attribute complexity consistency and feature correlation consistency are needed for the final decision. According to the conclusions of spatial analyses, more features and attributes are added to proposal two. Proposal two after modification becomes more complete and more reasonable and is recommended for the reference of contents refinement of NFGIS 1:50 000 DLG database. Finally, the paper presents the summaries with some questions to be studied in the future.