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Changes in extremity and seasonality of floods in the Zdobnice River basin
Čermák, Daniel ; Langhammer, Jakub (advisor) ; Šobr, Miroslav (referee)
The object of the bachelor thesis is to analyze the change of extremity and seasonality of floods in the Zdobnice basin. The literary research comprehensively presents floods with description of the biggest historical floods in the Czechia and in the Zdobnice basin. The literary research also includes the physical-geographical characteristic of the studied area. The practical part is based on the daily flow data analysis, obtained from CHMI (Czech Hydrometeorological Institute). Runoff analysis is performed on the base of these data, with focus on extreme flows. To compare the seasonality change, data series is divided into two periods (1945-1969 and 1970-2014), which point of change was determined by Pettit's and Buishand's homogeneity test. Seasonality change is compared by directional statistics, polar graphs, curves of cumulative frequency and flood index. As a result of these methods, it is found that in the second period, the flood risk is greater in earlier parts of the year. It has been also found, that there are more flood events in July. Key words: Floods, discharge, hydrological extremes, historical floods, seasonality, Zdobnice
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Floods – a natural phenomenon that would always shake to surprise
Munzar, Jan ; Ondráček, Stanislav
In the last twenty years, disastrous floods occurring in the Czech Republic affected smaller or larger areas (three extreme events occurred in 2010 alone). A particularly great surprise was the flood disaster in the summer of 1997, which caught a greater part of the population unprepared because several generations had not experienced a similar hydrological extreme – the historic memory of floods had been lost. In the past, people living along large rivers took into account the usual and often annually occurring natural phenomenon. However, the relation of today’s inhabitants in riverine landscapes and of the whole society to rivers and phenomena occurring on them changed during the 20th century. This is why the awareness of floods should be constantly restored, which is the aim of this work. The paper reminds and documents several disastrous floods, today already forgotten, occurring on Moravian or Bohemian rivers from the 16th century until the present and their impacts.
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Floods, landscape and people on the Morava/March River (on examples from the 17th up to 19th centuries)
Munzar, Jan ; Ondráček, Stanislav
In the natural conditions of central Europe, floods have been occurring at all times and we have to count on their occurrence in the future, too. None of the floods had the same behaviour and impact. All were unique and this is why the lessons learnt from historic flood cases are valuable for both the present time and the future. The analysis of the course of disastrous floods in the basins of Morava/March R. and Odra/Oder R. in July 1997 showed that the damage of properties and the high number of casualties were undoubtedly caused also by the loss of historic flood memory. Because our forefathers knew very well that floods are normal phenomenon and occur practically every year. The goal of this paper is to take our minds back to problems faced by inhabitants settled near the Morava River in connexion with floods and their impacts on examples from the period between the 17th-19th centuries.
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Documentation of flood events on Czech rivers at the end of the 18th and in the 19th century, based on the oldest hydrological measurements
Munzar, Jan ; Ondráček, Stanislav ; Elleder, L.
Disregarding the old flood marks, we can consider the beginning of hydrological measurements on Czech watercourses to be occasional observations made by prof. A. Strnad on the Vltava (Moldau) River in Prague in the 1780s where he watched the extreme water levels from his observatory in the Klementinum by using binoculars. The beginning of regular observations in our country is usually considered the measurement on the Vltava R. in Prague dated 1825, which is however somewhat disputable (as far as our knowledge goes, regular measurements are documented only two years later). Nevertheless, the authors succeeded in finding evidence about water level observations on the Odra River in Bohumín already from year 1820, which lasted respectable sixty years on the Austrian-Prussian section of the watercourse. The paper is focused namely on the analysis and evaluation of their half-forgotten results.
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The Jihlava River floodplain transformation on 1 April 2006 winter flood at Ivančice and Dolní Kounice.
Hrádek, Mojmír
The winter flood culminating on 1 April 2006 at Ivančice was generated by fast thawing of extremely thick snow cover which was accompanied by rain. The course of the flood in reach of the valley between Ivančice and Dolní Kounice was documented and a strong influence of dam reservoir of Dalešice of runoff in the Jihlava R. confirmed. The geomorphic effectiveness of the flood was not so big, nevertheless traces of erosion arisen by share stress of flood overbank flow and spectrum of depositional forms of slackwater from the end of flood was found. Features of founded geomorphic effects have been compared with that ones of the historical floods. An attempt to date some of erosional channels with floods from the years 1862 or 1876 has been made.
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Historical floods in Bohemia in the work of Dresden hydrometeorologist Christian Gottlieb Pötzsch. On the occasion of the 200th anniversary of his decease
Munzar, Jan ; Ondráček, Stanislav
This year, it was 200 years that have passed since the decease of the prominent Saxon hydrometeorologist Ch.G. Pötzsch (1732-1805), author of remarkable compendium “Chronological history of large flood events on the Elbe River in a thousand and more years“. The monograph was published in Dresden in 1784 and later added two annexes (from 1786 and 1800). It is a result of many years of hard work in the collection and study of most varied historical and contemporary sources of information. For the documentation of historical floods in Czech Republic the work by Pötzsch importantly also includes a range of data on the rise and course of concrete hydrometeorological extremes in the Czech segment of the Elbe River catchment and its affluents since the author drew his knowledge not only from historical entries (German, Czech and Latin) but also from available contemporary data originating from Bohemia, forgotten or unextant today.
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