Hrvatske vode, Vol. 31 No. 124, 2023.
Review article
A contribution to the analysis of the Sava river floods and high waters in september 2010 to Zagreb
Dušan Trninić
; Državni hidrometeorološki zavod Ravnice 48, Zagreb, Hrvatska
Tomislava Bošnjak
; Državni hidrometeorološki zavod Ravnice 48, Zagreb, Hrvatska
Abstract
The Slovenian Environment Agency (ARSO) issued advance warning about possible heavier rain on 16. 9. 2010 at 08:50 am, which read: “Heavy autumn rain is expected in Slovenia by the end of the week”. Since the forecast became a reality, it was necessary to declare the highest (red) alarm (according to Meteoalarm criteria) for the period from 17. 9. 2010 to 19. 9. 2010. The paper contains a detailed analyses of extremely heavy rain. The analyses of hydrological conditions in the Republic of Slovenia continue with Hydroalarm, which contains expected flood hazard states, all important hydrological data on high and floods waters, including the recorded maximum water wave values (date and time of the occurrence, water levels, discharges), return periods of maximum annual discharges (for 50, 100 and 1000 year return periods), as well as an overview of measured data (date and time of the occurrence, water levels, discharges), at hydrological stations selected for this analysis. Only 3 days and 9 hours passed between the advance warning on 16. 09. 2010 to the flood wave occurrence at the entry into the Republic of Croatia on 19. 9. 2010 at 6 pm.
The key flood defence facilities for the City of Zagreb are definitely the lateral canal in the right Sava dike at Jankomir and the Sava - Odra relief canal. The analysis of the flood wave in September 2010 included the calculation of the water quantity that flowed over the Jankomir weir. When the measured discharge at Zagreb is added to this value, the result is the largest, corrected discharge in the analysed period in 95 years. Due to various circumstances, the Jankomir weir is not sufficient for the design values and must be redesigned. The sediment regime, which is a very important component for every basin and every watercourse, is in the analysed area of the Sava basin only represented by data on suspended sediment. Unfortunately, the bed load is not measured anywhere at all.
Keywords
floods, high waters, Sava River, meteorology, hydrology, weir, canal
Hrčak ID:
315626
URI
Publication date:
29.6.2023.
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