The mean percentage error MPE Q_sim for all the considered cross-sections, as shown in Table 2, ranges between 0 and 5% for Q_sim1 and 0 and 2% per Q_sim2 (corresponding to R2 equal to 0.992 and 0.995, respectively). In light of this result, both Equations (17) and (19) can be deemed particularly reliable in discharge estimation when a good dataset, consisting of several velocity measurements over the whole flow area, is available.