Drainage network extraction using LiDAR-derived DEM in volcanic plains
Accurate delineation of drainage networks is critical for many hydrologically related applications. The commonly used methods for drainage network extraction from digital elevation models (DEMs) have limitations in low-relief terrain areas. High-quality DEMs are required for effectively applying these methods in extracting drainage networks in low-relief terrains. Airborne light detection and ranging (LiDAR) offers high-accuracy terrain data. With LiDAR data, high-accuracy and high-resolution DEMs can be generated. The results of drainage network extraction for two sub-catchments on the western Victorian Volcanic Plains (VVP) are reported. Drainage networks and some parameters describing drainage network composition, including the stream orders, the numbers of streams and the stream lengths, were derived from both the LiDAR DEM and the Vicmap DEM. The LiDAR-derived DEM is shown to offer significantly more detail, especially for delineating low-order stream (headwater) segments in sub-catchments of low-relief terrain.