GIS-Based Stream Network Analysis for the Upper Río Chagres Basin, Panama

To support a number of projects focused on diverse biological and physical science aspects of the upper Río Chagres basin, a detailed stream network was extracted from digital elevation data obtained by interferometric radar survey. The elevation data represented the bald earth surface plus a forest canopy of varying height. Therefore, different algorithms for stream network extraction were qualitatively evaluated in terms of their capability to extract accurate stream locations from this challenging type of elevation data. The programs based on a shortest path algorithm and an imposed gradients constraint provided stream locations that were closer to on-ground GPS measurements than the tools based on depressions filling and iterative linking. The influence of different spatial resolutions on network structure and orientation was also explored.