Effects of LIDAR DEM resolution in hydrodynamic modelling: model sensitivity for cross-sections

Abstract

With the development of science and technology the entire Earth, together with all of its phenomena, is gradually becoming an object of computer digitisation. For several years, this process has also affected water components, which are essential for the development of humans and economies on Earth. Therefore, monitoring of its resources and movement across the Earth's surface is the main object of investigation of several research institutions. In recent years, hydraulic modelling has experienced significant development that meets water and computer connection conditions. This study consequently dealt with hydraulic modelling and uncertainties in the data that may affect the resulting flood zone. We analysed the effect of cross-sections generated and the subsequent inundation areas in Digital Elevation Models of different resolutions. The basic DEM was constructed from data obtained by the LIDAR method. Hydraulic results were obtained using a one-dimensional (1-D) model, HEC-RAS, and its extension, HEC-GeoRAS. The Olše and Stonávka river junction, located in the northeast region of the Czech Republic, was selected for investigation. The resolutions selected for the study to generate cross-sections and the subsequent inundation areas were 1 m, 5 m and 10 m. The resulting cross-sections were confronted with the actual surveyed cross-sections.