THE CONSTRUCTION AND APPLICATIONS OF MAIN RIVER ENTITIES DATA

摘要

A river is presented by series arcs which are spatially end in end in a river geographic database traditionally. In order to better use the data, the main content of the paper is presenting the method of how to make the separated series arcs that present the same river (river entity) into a whole entity format. The main process includes the followings. Firstly we gain the name and code information of 1:1000000 main river data by matching the river data between 1:250000 and 1:1000000 database. Secondly we calculate the STRAHLER-rank(order) of each river arc according the Strahler rules except those whose rank are higher than 5 or those who have names. Based on foregoing work we have finally carried out the task that each river has one and only identity code. The paper also shows the advantage of using the result mentioned above.