Extraction and Code of Drainage Network Based on Digital Elevation Model

Firstly, the paper takes National Topographic Database by assuming DEM (digital elevation model) with 1:250,000 scale as a data source, extracts simulated drainage network by using Arc Hydro Tools 9.2. Secondly, a new coding method is presented, which can reflect the topology of drainage network. It becomes easily to locate any reach of drainage network directly and operate the topology of drainage network effectively. Finally, this coding method is applied to Hunhe drainage system of Liaohe basin. The successful application proves that the self-replicating code has excellent expansibility and high efficiency, and can be handled easily by the computer.