ve spatial data

an algorithm of“Coordinate-consolidation Overlay”was presented. The appropriate threshold value was selected according to analysis of spatial data overlay. An extended module was developed based on this algorithm in Oracle Spatial. The correctness and validity of the solution were testified by using the spatial data in which bug happened for Oracle Spatial. In the end

an application example in overlay analyses of nationwide municipality-county map and land-use map at scale 1∶4000 000 was given by using the extended module of Oracle Spatial.