Details

Autor(en) / Beteiligte

• Elleder, Libor
• Krejčí, Jakub
• Racko, Stanislav
• Daňhelka, Jan
• Šírová, Jolana
• Kašpárek, Ladislav

Titel

Reliability check of flash-flood in Central Bohemia on May 25, 1872

Ist Teil von

• Global and planetary change, 2020-04, Vol.187, p.103094, Article 103094

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The flash flood occurring on May 25, 1872 ranks among the most extreme events recorded within the Czech Republic. The causative torrential rain affected mostly the area between Karlovy Vary, Plzeň and Prague of approximately 2000 km2. A corresponding intensity of precipitation observed incidentally at two sites exceeded 200 mm in 3–8 h. The consequent flood caused tremendous damages to ponds, houses, and infrastructure and resulted in a temporary collapse of transport especially due to a total break of trains operation. The flood led to approximately 240–300 fatalities according to various sources. An extent of the total area affected reached approximately 2000–3000 km2 representing an unusually large scale for such a type of flood. The intensive rain and inflow caused the biggest rupture of a water reservoir in Mladotice so far. The respective Mladotický pond held very likely 3–4 million cubic meters of water before its rupture. With a delay of 2 to 3 days, a substantial saturation triggered a massive landslide blocking the Mladotický water stream and creating a new water body named the Odlezelské Lake. The flood event motivated elaboration of at least 3 scholarly papers already between 1872 and 1875. Accordingly, this flood presents for Czech hydrologists an outstanding example of such an extreme magnitude until now. The flood in 1872 and drought in 1874 led directly to establishing the Hydrological service of the Czech Kingdoms in 1875. Hitherto, we have no comparison for such extreme flood including recent floods occurring in 2002, 2010 and 2013. The flood peaks exceeded other historical or recent floods by at least 1–2 m. There is only one similar flood event, the flood of July 31, 1714 at the Sázava River catchment. As there were no regular hydrological observations including precipitation measurements available for the affected areas before 1883, the prevailing data source comprise documentary sources and their relevant interpretations. The aim of our study is to explain in a more detail the course of this flood and a number of indeterminate circumstances during the flood. An important question was an effect of the collapse of approximately 100 ponds and a role of the collapsed sizeable Mladotický pond. These phenomena were partly explained by newspapers and chronicles describing an incredibly rapid increase of water level (2–3 m in a few minutes) at a relatively large number of sites. We have completed a hydraulic estimation of peak discharges at major profiles. In our research we used the Aqualog hydrological modelling system. The hydrological modelling enabled us to complete and check the reliability of observed causative precipitation for the affected area and peak flow rates at the Beroun and Prague municipalities. An important point was the reconstruction of a flow hydrograph at Prague with very intricate shape and two likely local peaks. Second local maximum could be attributed to the collapse of the Mladotický pond. This flood is of crucial importance for the Prague flood protection system. The main reason being a short time span of 22 h between the beginning of causative rainfall and occurrence of maximum flood flow rate at Prague. •We applied the hydrological modelling system Aqualog routinely used by the CHMI hydrological service.•We conclude that the observation of precipitation 240–290 mm in 90 min in Mladotice is credible.•1872 extreme flood within a warm and dry period indicates that an analogy is not ruled out under current climate change.•If a similar situation occurs today, mobile barriers in Prague would be installed based only on meteo forecast.