# Multitemporal SAR Data and 2D Hydrodynamic Model Flood Scenario Dynamics Assessment
## 4 Results and Discussion
### Validation Performance Measures
Over-prediction is not surprising since the hydrodynamic model's failure to include hydrological components of the floodplain mass balance (infiltration, direct precipitation, evapotranspiration, and local runoff) and considering the tendency to be bordered by relatively dense vegetation which increases height errors, e.g., in zones closer to the channel meander in the river mouth. These features clearly merit further investigation, however it is more likely that the deterioration in model performance during floodplain dewatering was due to failure to characterize minor floodplain drainage channels correctly within the model or to inherent deficiencies in model formulation, as highlighted in [61]. Moreover, the high \(FA2\) values confirm the successful adaptation of the model to observed SAR-derived data. However, the better performance of calibration results with respect to validation outcomes in term of statistical measurements could be due to the lower magnitude of the event that was analyzed during the calibration, and, as consequence, the lower spatial extension of the flood event that may simply be easier to predict by hydrodynamic model; the difference between calibration and validation statistical \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{1}{c}{**Statistical Performance Measurements of Flood-Extent Estimation 2 December 2013**} \\ \hline  & \(r_{fp}\) & \(r_{tp}\) & \(r_{fn}\) & \(MSE\) & Accuracy & Sensitivity & Specificity \\ \hline \(c\) & & & & & & \\ _0.04 for channel and floodplains_ & 10.35 & 66.07 & 33.93 & **44.28** & 85.17 & 66.07 & 89.65 \\ _0.08 for channel and floodplains_ & 12.71 & 76.17 & 23.83 & **36.54** & 85.17 & 76.17 & 87.29 \\ _0.1 for channel and floodplains_ & 30.52 & 92.55 & 7.45 & **37.97** & 73.86 & 92.55 & 64.48 \\ _0.033 for channel and 0.06 for floodplains_ & 13.57 & 72.95 & 27.05 & **40.62** & 83.87 & 72.95 & 86.43 \\ _0.025 for channel and 0.01 for floodplains_ & 10.17 & 65.88 & 34.12 & **44.29** & 85.28 & 65.88 & 89.89 \\ _variable in time and space_ & 24.17 & 98.53 & 1.47 & **25.64** & 80.15 & 98.53 & 75.83 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Results of hydraulic simulation model calibration performance for 2 December 2013 in terms of a flood extent map: the set of Manning coefficients \(c\), false positive rate \(r_{fp}\), true positive rate \(r_{tp}\), negative rate \(r_{fn}\), minimized sum of errors (\(MSE\)), and accuracy, sensitivity, and specificity. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{1}{c}{**Statistical Performance Measurements of Flood-Extent Estimation 3 December 2013**} \\ \hline  & \(r_{fp}\) & \(r_{tp}\) & \(r_{fn}\) & \(MSE\) & Accuracy & Sensitivity & Specificity \\ \hline _0.04 for channel and floodplains_ & 9.24 & 45.12 & 54.88 & **64.12** & 87.01 & 45.12 & 90.76 \\ _0.08 for channel and floodplains_ & 20.7 & 70.37 & 29.63 & **50.33** & 78.57 & 70.37 & 79.3 \\ _0.1 for channel and floodplains_ & 32.13 & 91.93 & 8.07 & **40.2** & 69.85 & 91.93 & 67.87 \\ _0.033 for channel and 0.06 for floodplains_ & 14.05 & 52.74 & 47.26 & **61.31** & 83.22 & 52.74 & 85.95 \\ _0.025 for channel and 0.01 for floodplains_ & 8.97 & 44.69 & 55.31 & **64.28** & 87.22 & 44.69 & 91.03 \\ _variable in time and space_ & 18.16 & 81.27 & 18.73 & **36.89** & 81.79 & 81.27 & 81.84 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Results of hydraulic simulation model calibration performance for 3 December 2013 in terms of a flood extent map: the set of Manning coefficients \(c\), false positive rate \(r_{fp}\), true positive rate \(r_{tp}\), false negative rate \(r_{fn}\), minimized sum of errors (\(MSE\)), and accuracy, sensitivity, and specificity. performances could also due to the fact that the uncertainties in the model results could be proportional to the amount of the analyzed flooded cells.