Integrating automatically processed SPOT HRV Pan imagery in a DEM-based procedure for channel network extraction

The contribution of automatically processed Système Pour l’Observation de la Terre (SPOT) high resolution visible (HRV) Pan data as an ancillary source of information to a digital elevation model (DEM)-based method for channel network extraction is introduced. The image processing stage included an application of a Laplacian filter for edge detection. Edge pixels that were not contiguous with the main channel network were eliminated and the channel network was buffered and finally skeletonized to create channels with one-pixel width. A DEM-based approach was implemented for an overlapping area using the terrain analysis using digital elevation models (TauDEM) procedure based on the principles of the flow direction matrix method. The channel network that was extracted by the use of the two methods in fusion was tested against the imagery, and the DEM-based, channel networks and conformed to the reference data more accurately in terms of coverage of channels, network connectivity and location of extracted channels. A disadvantage of the data fusion is the additional, few, artificial channels.