Digital elevation models: altimetric corrections for hydrological usage in flat areas

Abstract

“Digital elevation models: altimetric corrections for hydrological usage in flat areas”. The representation of water movement on the ground towards the courses of water is generated from the processing of topographic maps in an environment of geographic informa - tion systems and remote sensing. The objective of this work was to define a surface drainage system in a plain basin based on a geodetically adjusted digital elevation model in the north of the Salado River Basin (A1 region). Drainage vector layers and the SRTM90 topography information were used as primary data. The latter has been geodetically adjusted through GPS and levelling information. With the corrected SRTM and the Arc Hydro Tools, it was possible to define a drainage system that involves the corrected A1 region. Finally, a multi-temporal analysis of water bodies, from different sources of national (IGN) and international information (Dartmouth Flood Observatory, USA) was carried out. This allowed differentiating its surface occupation behavior during dry or flood periods, and contributes to taking the appropriate decision to prevent or mitigate alerts from the rising of water bodies in a flat area of similar extension; especially in places close to populated or agricultural areas. It is concluded that as the topographic features of a region are detailed and corrected by means of geodetic data, it is possible to delimit a watershed together with its surface drainage system with more precision