Professional paper

Hydrological analysis of mean annual discharges along the Sava River in Croatia

Ognjen Bonacci orcid.org/0000-0002-7123-3421 ; Sveučilište u Splitu, Fakultet građevinarstva, arhitekture i geodezije, Split, Hrvatska *
Tanja Roje-Bonacci ; Sveučilište u Splitu, Fakultet građevinarstva, arhitekture i geodezije, Split, Hrvatska
Duje Bonacci orcid.org/0000-0002-8168-1367 ; Sveučilište u Zagrebu, Fakultet hrvatskih studija, Zagreb, Hrvatska

* Corresponding author.

Abstract

The paper analyses all available series of mean annual discharges calculated at 13 gauging stations along the Sava River in Croatia. Only official data from the Croatian Meteorological and Hydrological Service (DHMZ), Zagreb, were used. The series lengths differ, there are interruptions in monitoring within individual series, but all end with 2022. A decreasing trend in mean annual discharges has been clearly observed at all gauging stations. The values of linear regression coefficients, a, indicate an intensification of the decreasing process in downstream direction along the river course. The average value of decreasing in the upper course is 7 m3/10 years, in the middle course to 11 m3/10 year, while the stations in the lower course record 22 m3/10 year. The analysis of difference in discharges between the neighbouring gauging stations revealed certain irregularities that indicate probable errors in the determination of mean annual discharges at some stations. It seems that the least reliable determinations of discharges occur at the Podsused, Rugvica and Jasenovac stations, the probable reason being insufficient number of measurements to determine reliable discharge curves. The Hurst exponent was calculated for the series of the Sava River at Zagreb (1926-2022) and Županja (1929-2022). Since its value equals 0.68 for Zagreb and 0.70 for Županja, it can be assumed that mean annual discharges along the entire river course in Croatia contain long-term memory.

Keywords

mean annual discharge; Sava River; Croatia; Hurst exponent

Hrčak ID:

326755

URI

https://hrcak.srce.hr/326755

Publication date:

2.4.2024.

Article data in other languages: croatian german

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