FEATURE-BASED DERIVATION OF DRAINAGE NETWORKS

An approach to the automatic derivation of drainage networks from digi tal elevation models (DEMs) using regular-gridded data is described. F eatures such as depressions and plateaus, on which drainage directions are undefined, are handled as entities in their own right, and are id entified using operations on connected regions. Such an approach is a departure from the traditional pixel-based (local) approaches and faci litates the construction of a consistent drainage network. A single or multiple flow drainage model can be implemented. Accumulation and wat ershed delineation of the drainage network are performed by recursivel y climbing ascending paths from sink points. The algorithms are signif icantly faster than those of other approaches and operate within an ef ficient buffering scheme which facilitates handling of large DEMs and multiple data sources.