Based On The Major Hazards Of Gis Spatial Database Technology Research

Geographic Information System(GIS) is widely used in the fields of geosciences. resource management,plan of land utilization,environmental test,disaster prevention and mitigation,electric power industry,traffic control,town planning,scientific research,education and national defence and so on ,which plays an important role in economic development in China. GIS is the main body in the development of spatial data. Spatial data is the blood of GIS. At the present time ,Spatial Query Technology is not very mature, due to the hugeness of spatial data size and the complexity of spatial object and spatial query .During the process of practical application, consumers always hope spatial data base can offer functions that are able to calculate relations of spatial objects (Eg: topologic relation . ordinal relation,metric relation)more directly .However, it is difficult to finish the rogatory function of direct calculate spatial objects better, toward today's mature GIS and spatial data base. Because of the complexity of spatial data and the uncertainty of consumers' demands, it is impossible to anticipate the spatial queries which are brought out by consumers. So we should solve the query of spatial data base fundamentality. The most important is spatial data accessing technique which is made of spatial index and operations based on spatial index, is the technologic foundation of spatial query.R-trees is one of the most widely used spatial data accessing techniques at present, and that clustering analyze has been widely studied many years as a embranchment of statistics. This text contains a systemic analysis towards R-trees spatial data accessing technique and a detailed introduction of clustering analyze technology. And then I lodged R-trees index based on clustering technology to improve the capability of spatial data query management. Then I designed and carried out the fatal hazardous source spatial data query experimental system thought MapInfo files system and MapX 's second exploitation based on VC++ programmed platform .And I finished basic query between graphics and context\ spatial point query \district query \most nearest neighbor query.