Evaluation of the 1D hydraulic simulation of a natural channel of short length, generated from the use of ALOS PALSAR data

Abstract

The results of the 1D hydraulic simulation of a short natural channel, obtained from the use of the ALOS PALSAR Digital Elevation Model (DEM) as a source of topographic information, were evaluated. A simulation of the study area was developed using a DEM made by means of a topographic survey with a total station, from geodetic points properly georeferenced in the study area; this was considered as the reference to evaluate the simulation using ALOS PALSAR data. To obtain the design flow, a hydrological simulation of the microbasin with drainage towards the beginning of the model channel section was carried out. The channel hydraulics were simulated considering the information from the topographic survey as a reference, and contrasting it with the simulation obtained from the remote sensor. The results obtained from the NSE and RSME statistical metrics show that the use of the ALOS PALSAR DEM for the hydraulic simulation of the channel under study, generates significant variations with respect to the results obtained when using a DEM obtained by a higher precision technique, such as the field survey with a topographic station, which indicates that this terrain model is not advisable to use when high precision results are required in large scale scenarios.