Here I present a method for drainage network extraction from high-resolution Digital Elevation Models (DEMs) (e.g. those derived from Airborne Laser Swath Mapping (ALSM)) that requires just two user-defined parameters and is capable of handling discontinuous valley networks. I illustrate the accuracy and robustness of the method using synthetic valley networks that mimic the complexities of real landscapes and for which the true drainage network is known exactly, by construction. The method involves six principal steps: optimal Wiener filtering to remove microtopographic noise, mapping of the contour curvature, identification of valley heads using a user-defined contour-curvature threshold criterion, routing of a unit discharge of water from each valley head using a multiple-flow-direction routing algorithm, removal of discontinuous reaches from the drainage network using a user-defined discharge-per-upstreamvalley-head threshold criterion, and thinning of the valley network to a single pixel width. The method yields accurate results using the same user-defined parameters for the two field sites considered here, suggesting that, for DEMs with resolution ~1 m, the method has the ability to produce accurate results for a variety of landscapes using the same parameter values employed here.
Pelletier J. D. (2013): A robust, two-parameter method for the extraction of drainage networks from high-resolution Digital Elevation Models (DEMs): Evaluation using synthetic and real-world DEMs. Water Resources Research 49(1): 75–89. DOI: 10.1029/2012WR012452
This Paper/Book acknowledges NSF CZO grant support.