Flood frequency estimation is one of the most important tasks for hydraulic engineers. Design of hydraulic structures and systems require reliable estimates of high waters, which is not always easy to deliver. In this paper, uncertainty of flood frequency estimation common in practical use is presented in the case study of the Sava River at the Sremska Mitrovica hydrological station. Time series of 42 years daily flow records are statistically analysed on two samples, comprising annual maxima (AM), and peaks over threshold (POT). For uncertainty assessment, samples are analysed for several different scenarios, i.e. varying AM sample length as well as threshold flow for POT. Results indicate large uncertainty of flood frequency estimates, especially in the domen of low probabilities, as well as problem of adopting final value for practical use that will provide safety and optimum cost of the structures.
References
[1]
V. Vukmirović, *Analiza verovatnoće pojave hidroloških veličina*. 1990.
[2]
S. Mkhandi, A. Opere, and P. Willems, “Comparison between annual maximum and peaks over threshold models for flood frequency prediction,” in *Int. Conf. UNESCO Flanders FIT FRIEND/Nile Proj. – ’Towards a better Coop.*, vol. 1, 2005, pp. 1–15.
[3]
S. Fischer and A. Schumann, “Comparison between classical annual maxima and peak over threshold approach concerning robustness,” Sonderforschungsbereich, vol. 823, 2014.
[4]
H. Madsen, P. F. Rasmussen, and D. Rosbjerg, “Comparison of annual maximum series and partial duration series methods for modeling extreme hydrologic events: 1,” At site modeling. *Water Resources Research*, vol. 33, no. 4, pp. 747–757, 1997.
[5]
V. T. Chow, D. R. Maidment, and L. W. Mays, *Applied hydrology*. 1988, p. 565.
[6]
B. Merz and A. H. Thieken, “Separating natural and epistemic uncertainty in flood frequency analysis,” *Journal of Hydrology*, vol. 309, pp. 114–132, 2005.
[7]
C. Wright and D. Kemp, “Flow estimation for flood management: Understanding the uncertainty,” in *5th Flood Management Conference*, Warrnambool, 2007, pp. 1–8.
[8]
Ž. Topalović, “Praktični problemi određivanja mjerodavnih velikih voda za potrebe projektovanja sistema odbrane od poplava,” in *Zbornik radova sa 17. Savetovanja SDHI i SDH*, Vršac, 5–6 October, 2015, pp. 893–903.
[9]
N. T. Kottegoda and R. Rosso, *Applied statistics for civil and environmental engineers*. 2008.
[10]
D. A. Darling, “The Kolmogorov-Smirnov, Cramer-von Mises tests,” *Annals of Mathematical Statistics*, vol. 28, no. 4, pp. 823–838, 1957.
[11]
S. Jovanović, *Primena metoda matematičke statistike u hidrologiji*. 1977.
[12]
T. B. Arnold and J. W. Emerson, “Nonparametric goodness-of-fit tests for discrete null distributions,” *R Journal*, vol. 3, pp. 34–39, 2011.
[13]
J. D. Salas, “Introduction to hydrology,” in *Handbook of Environmental Engineering 15: Modern Water Resources Engineering*, 2014, pp. 61–94.
[14]
J. Beirlant, Y. Goegebeur, J. Teugels, J. Segers, D. Waal, and C. Ferro, “*Statistics of extremes,” Theory and applications*, vol. 47, no. 3, 2005.
[15]
J. H. Heo, J. D. Salas, and K. D. Kim, “Estimation of confidence intervals of quantiles for the Weibull distribution,” *Stochastic Environmental Research and Risk Assessment*, vol. 15, no. 4, pp. 284–309, 2001.
[16]
USWRC (United States Interagency Advisory Committee on Water Data, Hydrology Subcommittee. 1982.
