Hydraulic parameter identification using aerial photographs

Some parameters embedded in open-channel flow equations lack definitive measurement methods. Optimal values of these parameters in a mathematical sense can be identified by using assimilation methods. New generations of satellites are now able to provide observation data that can be useful to implement inverse problems. Assimilation techniques such as variational assimilation or the Kalman filter have been tested on a simple case, in order to find the most appropriated method for the hydraulic parameter identification. This method has then been implemented on a real case: this paper presents the results of hydraulic parameter identification on the Aisne River, using air photos of the flood of December 1993.