Methods for identifying the size, or scale, of hillslopes and the extent of channel networks from digital elevation models (DEMs) are examined critically. We show that a constant critical support area, the method most commonly used at present for channel network extraction from DEMs, is more appropriate for depicting the hillslope/valley transition than for identifying channel heads. Analysis o...

[1] In this article, a method for drainage network extraction from high-resolution digital elevation models (DEMs; e.g., those derived from airborne laser swath mapping) is presented, which requires just two user-defined parameters and is capable of handling discontinuous valley networks. The accuracy and robustness of the method are illustrated using synthetic valley networks that mimic the co...

OBJECTIVES To assess the probability of spontaneous stone passage and its predictors after drainage of obstructed kidney by JJ stent, as insertion of an internal ureteric stent is often used for renal drainage in cases of calcular ureteric obstruction. PATIENTS AND METHODS Between January 2011 and June 2013, patients for whom emergent drainage by ureteric stents were identified. The patients'...

An automated process for the delineation of drainage basins, using as input only the vector based drainage network, is described which provides an alternative to DEM based methods. The procedure involves an approximation of the line Voronoi diagram for the network using a constrained Delaunay triangulation of the network's Planar Straight Line Graph. The constrained triangulation, which include...

This paper describes a new fast and scalable parallel algorithm to compute global flow accumulation for automatic drainage network extraction in large digital elevation models (DEM for short). Our method uses the D8 model to compute the flow directions for all pixels in the DEM (except NODATA and oceans). A parallel spanning tree algorithm is proposed to compute hierarchical catchment basins to...