Establishing topology of submarine geomorphologic map

To design the maps of China's marine project,a mapping technology is explored on the basis of map soft ware of MBChart,which has been established during a China's high tech project from 1996 to 2000,a program of five steps to establish to pological tree is proposed o design submarine geomorpho logic map.(1)Self intersecting curves and intersecting curves and isolated arcs are found and edited until these arcs meet the rule of establishing the topological tree.(2)Anodes network is established which is composed of the arcs extreme points,these arcs are appended to the node chain structure by the order of azimuth angle of closed two arc points,so the bidirectional relationship between the nodes and the arcs is established.(3)The topological area is esablished which is composed of the arcs traced from the nodes network.(4)The nested relationship of polygons is established through minimum external rectangle of polygons and the method of counting angles which are used to determine the relationship between the point and the polyg on,the to pological tree is established finally.(5)The topological areas are edited and the submarine geomorphologic maps are designed through man machine conversation on the basis of map software of MBChart.The geomorphologic maps of China's marine project have been accomplished based on this program.The topological technology will be applied to the geology and geophysics study such as data display and complex area count.