Major hazard based on GIS spatial database technology research
|Course||Software and Theory|
|Keywords||Geographic Information Systems Spatial index R- tree Cluster analysis Sources of danger assessment MapX|
Geographic information system (Geographic Information System, GIS) is widely used in science, resource management, land use planning, environmental monitoring , disaster prevention and mitigation , the field of power industry , traffic management , urban planning , research , education and defense in our national economy play an increasingly important role in the construction . GIS is the main spatial database development , spatial data , GIS blood . Due to the huge amount of spatial data , and space objects , spatial query highly complex nature , the current spatial query technology is not very mature . In the actual application process , users often want to spatial database can provide some more direct calculation of the space object relations (such as topological relations , order relations , metric relations , etc.) functionality , but mature GIS systems and spatial database better direct calculation of space object relations function query also more difficult . It is because of the uncertainty of the complexity of spatial data and user needs , prior to expected users may propose spatial query is impossible , which requires a fundamental solution to the spatial database query . During important spatial data access methods , spatial index on the spatial index operation , the technical basis of the spatial query . R- tree is the most widely used as a spatial data access methods , as a branch of statistics , cluster analysis has been extensively studied for many years . R- tree spatial data access methods , systems analysis , and cluster analysis techniques described in detail , based on R- tree index -based clustering method to improve the performance of query processing of spatial data . Then use the the MapInfo file system , through VC programming platform integration MapX secondary development Nanming District the major hazard spatial data queries experimental system was designed and implemented , completed basic graphic mutual inspection , spatial point query , and region query nearest neighbor queries .