For the Tanaro (Ta) River, H0 and ξ are set equal to 30 meters and 0.1, respectively. The same flood durations, i.e., 12, 24, and 48 hours, are considered for the analysis that is carried out only for 200 years’ return period. The results, summarized in Table 2, show that two of the investigated levees are overtopped; one is characterized by low vulnerability, while three are found prone to seepage. Specifically, for Ta1sx and Ta2dx the highest probabilities are computed and are found higher than 0.55 when the longest flood duration is considered. Figure 7 shows the results for Ta1sx that is characterized by mean vulnerability for all the investigated flood durations.
Close modal
Table 2
As for Table 1, but for the Tanaro River and for a return period of 200 years
| Left side levee | Vulnerability class (seepage probability) | Right side levee | Vulnerability class (seepage probability) | ||||
|---|---|---|---|---|---|---|---|
| D = 12 hr | D = 24 hr | D = 48 hr | D = 12 hr | D = 24 hr | D = 48 hr | ||
| Ta1sx | mean (0.34) | mean (0.42) | mean (0.56) | Ta1dx | overtopping | overtopping | overtopping |
| Ta2sx | overtopping | overtopping | overtopping | Ta2dx | mean (0.34) | mean (0.41) | mean (0.57) |
| Ta3dx | low (0.28) | mean (0.35) | mean (0.48) | ||||
| Ta4dx | low (0.06) | low (0.09) | low (0.17) | ||||
| Left side levee | Vulnerability class (seepage probability) | Right side levee | Vulnerability class (seepage probability) | ||||
|---|---|---|---|---|---|---|---|
| D = 12 hr | D = 24 hr | D = 48 hr | D = 12 hr | D = 24 hr | D = 48 hr | ||
| Ta1sx | mean (0.34) | mean (0.42) | mean (0.56) | Ta1dx | overtopping | overtopping | overtopping |
| Ta2sx | overtopping | overtopping | overtopping | Ta2dx | mean (0.34) | mean (0.41) | mean (0.57) |
| Ta3dx | low (0.28) | mean (0.35) | mean (0.48) | ||||
| Ta4dx | low (0.06) | low (0.09) | low (0.17) | ||||
The levees affected by failure during the severe flood of November 1994 are in bold.
Figure 7
As for Figure 6, but for the Tanaro River levee Ta1sx, return period = 200 years (/Hs = 0.79).
Figure 7
As for Figure 6, but for the Tanaro River levee Ta1sx, return period = 200 years (/Hs = 0.79).