Uncertainty in the Extracted Drainage Network Associated to the Applied DEM Correction Method: Implementation of a new DEW Correction Approach

Juan Camilo Castro Gallego1, Veronica Botero Fernandez2, and Jaime Ignacio Velez3
Facultad de Minas, Universidad Nacional De Colombia, Medellin, Colombia
1. *jccastro70@gmail.com; 2. vbotero@unal.edu.co; 3. jivelezu@gmail.com

Abstract: Automated generation of drainage networks from digital elevation models (DEM) has become a popular practice due to the increment of available information. Along with the different methods proposed for the automated extraction of drainage networks, new methods to correct the DEMs have also been suggested. This paper analyses the uncertainty related to the extraction of drainage networks from several DEMs when using different correction methods, including a new approach suggested by the authors. The automated extraction of the drainage networks was made from DEMs, at different scales, corrected with three different approaches: 1) ArsGIS's sink filling and flow direction method (ArcGIS is a commercial GIS package from the Environmental Systems Research Institute ESRI). 2) Tarboton's (1997) TauDEM (methodology proposed and implemented by David Tarboton, students and collaborates in Utah State University) implemented for the free/open software MapWindow GIS in 2005 by his team and other contributors from Idaho State University. 3) HidroSIG 4.0 DEM processing functions (methodology proposed and implemented by the authors of this paper in the free software HidroSIG 4.0 from the Universidad Nacional de Colombia, sede Medellin). This methodology suggests a new approach based on the physical processes that take place on river networks and their geomorphological tendencies due to the work done by long term erosive processes. The different river networks extracted from different processed DEMs, from a mountainous tropical area in Colombia, at four different resolutions, were analyzed to determine their inherent uncertainty due to the correction and flow direction definition method used for the automated extraction.

Keywords: Uncertainty, digital elevation models (DEM), automated extraction of drainage networks, DEM processing, river networks

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