Abstract:
In terms of inundated area, the largest floods in Portugal occur in the Lower Tagus River. On average, the river overflows every 2.5 years, at times blocking roads and causing important agricultural damages. This paper focus on the calibration of 2D-horizontal flood simulation models for the floods of 2001 and 2006 on a
70-km stretch of the Lower Tagus River. Flood extent maps, derived from ERS SAR and ENVISAT ASAR
imagery were compared with the flood extent maps obtained for each simulation, to calibrate roughness
coefficients. The combination of the calibration results from the 2001 and 2006 floods provided a preliminary
Manning coefficient map of the study area.