Geografie 2026, 131, 1-26
Flood frequency analysis of the Rasina River in Serbia
, Nataša Martić-Bursać1, Milena Gocić1, Nikola Milentijević2, Marko Ivanović2
1University of Niš, Faculty of Sciences and Mathematics, Department of Geography, Niš, Serbia
2University of Priština in Kosovska Mitrovica, Faculty of Sciences and Mathematics, Department of Geography, Kosovska Mitrovica, Serbia
Received July 2025
Accepted February 2026
In this paper we performed flood frequency analysis by using L-moments and annual maximum series data from two hydrological stations on the Rasina River (Brus and Bivolje), for the 1961−2020 period. Homogeneity testing confirmed that the basin can be considered hydrologically homogeneous (Vi = 0.38 < 1). Five probability distributions – Normal, Log-Normal, Gumbel, Pearson Type III, and Log-Pearson Type III – were tested to identify the best-fit model. An L-moment ratio diagram and Z-statistics indicate that all distributions satisfy the test criteria, with Log-Pearson Type III showing the best overall fit for the region (Z = 0.09). Goodness-of-fit tests (Kolmogorov-Smirnov, Cramér-von Mises, and χ2) confirmed Log-Pearson Type III as the best fit at the Brus station and Pearson Type III at the Bivolje station. Theoretical flood quantiles were calculated for various return periods (T-year floods). Mann–Kendall trend analysis indicated a significant decreasing discharge trend at Bivolje (−1.28 m3/s per year).
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Funding
This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Agreement No 451−03-137/2025–03/ 200124), Faculty of Sciences and Mathematics, University of Niš.
