Effects of Spatial Resolution on Topographic Representations and Drainage Networks Derived from LiDAR Digital Terrain Model

Digital Terrain Models (DTM) derived from LiDAR technology are increasingly available. However, working with these DTMs causes high computational costs and requires high-performance equipment, which may even make the use of these models unfeasible. The objective of this work is to evaluate the effects caused by changing spatial resolution in topographic representations and drainage networks extracted from LiDAR-DTM. For this, three resampling techniques were applied, mean aggregation, bilinear interpolation and nearest neighbor interpolation, to coarse a 1 m spatial resolution LiDAR-DTM in multiple resolutions (2, 10, 30 and 100 m). A sub-basin (550 km²) of the Sirinhaem River basin was taken as the case study area. The results show that there was no significant difference between the resampling techniques, but between the spatial resolutions, varying according to the applied metric. The spatial resolution of 2 m is more suitable in case of the need for a coarser resolution.