Figure 4. Comparison of the observed total runoff depths with the estimations by the SCS runoff curve number method
Table 4 shows the results of probability distribution fitting. The high values of the significance level indicate that the null hypothesis is difficult to reject in all the cases. Figures 5-10 depict the empirical and the two fitted distributions for each variable. The durationT , the total rainfall depth at the observation system, the total rainfall depth at the auxiliary raingauge, and the bulk runoff coefficient well fit to the LN3. Fitting of to GEV is even better. However, the total runoff volume and the maximum runoff discharge , which determine the two critical parameters of the spillway design discharge and the reservoir capacity, do not fit very well to any of the two distributions though the LN3 for and GEV for are still acceptable. The remarkable concentration of the observed values around 300 (m3) causes the irregular shape of the empirical distribution of .
Table 4. Results of probability distribution fitting