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Saturation of the Czech territory by precipitation before extreme precipitation totals
Laco, Martin ; Müller, Miloslav (advisor) ; Ledvinka, Ondřej (referee)
The saturation of the river basin is one of the important factors that contribute to the occurrence of significant floods. Examples of floods where significant previous saturation played a significant role are, for example, the floods of 1997, 2002 and 2013. A more detailed description of saturation before heavy rainfall in the Czech Republic was missing. The main goal of the work was therefore to describe the distribution of saturation using a suitable index of saturation before cases of heavy precipitation in the Czech Republic, and also to try to describe the degree of risk associated with high saturation in combination with heavy precipitation, using the proposed indicator of the importance of relative saturation. Based on the results of the work, we can say that, in general, the saturation before heavy precipitation totals can be diverse (mainly for the shortest analyzed time intervals), but on average it is rather normal. It is slightly increased in the mountain area, especially in the east of the country and for strong precipitation totals of the longest analyzed time intervals. However, when taking into account the extremity of heavy precipitation totals, it turns out that the saturation tends to be significantly increased mainly for the heaviest precipitation of longer time intervals in...
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Runoff generation in urban environment
Píchal, Jan ; Daňhelka, Jan (advisor) ; Čekal, Radek (referee)
As the area of impervious surfaces at urban environment increases, the more rapid runoff and urban flash floods lead to frequent overflow of the sewer system. For storm water runoff prevention and mitigation, there are soakaways commonly built in newly build up areas. The soakaways volume calculation is given by ČSN 75 9010 regulation in the Czech Republic. The presented thesis verifies applicability of this regulation in selected study sites (smal basins) of projected building construction model basins, which differ with regard to their infiltration characteristics, slope, area and degree of planned urbanization. The runoff calculation was estimated by Clark's Unit Hydrograph (UH) transformation and triangular SCS UH. HEC-HMS software has been used for Clark's UH application. Triangular UH runoff calculation has been done using MS Excel environment to establish a series of equations and logical conditions. Both models' results were compared for storms with 5 years, 10 years, 100 years and theoretical maximum return period; thus also for storms with longer return period than is proposed in the regulation. The positive differences in soakaway peak overflows and peak runoffs in study sites before the start of the urbanization were compared and evaluated, together with the differences in soakaway...
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Compound hydrometeorological events
Laco, Martin ; Müller, Miloslav (advisor) ; Pejchová Plavcová, Eva (referee)
This bachelor thesis deals with compound hydrometeorological events and provides overview of recent knowledge of this significant natural phenomena. There have risen several definitions of compound hydrometeorological events in recent years. All of these definitions are connected with condition of simultaneous occurrence of two, possibly more dangerous meteorological or hydrological threats. Examples are simultaneous occurrence of drought and heatwave. One of the aims of the study was to attempt classication of compound hydrometeorological events. Based on recent knowledge, it is possible to look at this type of threat from two main perspectives. The first perspective could be a description of a compound event as a random combination of dangerous threats, while the second perspective illustrates the dangerous phenomena as interdependent events. The practical part outlines some examples of associated hydrometeorological events that occurred in the Czech Republic with the help of brief case studies. Key words: compound hydrometeorological events, simultaneous occurrence, storm surge, heavy precipitation, drought, heatwave
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Runoff generation in urban environment
Píchal, Jan ; Daňhelka, Jan (advisor) ; Čekal, Radek (referee)
As the area of impervious surfaces at urban environment increases, the more rapid runoff and urban flash floods lead to frequent overflow of the sewer system. For storm water runoff prevention and mitigation, there are soakaways commonly built in newly build up areas. The soakaways volume calculation is given by ČSN 75 9010 regulation in the Czech Republic. The presented thesis verifies applicability of this regulation in selected study sites (smal basins) of projected building construction model basins, which differ with regard to their infiltration characteristics, slope, area and degree of planned urbanization. The runoff calculation was estimated by Clark's Unit Hydrograph (UH) transformation and triangular SCS UH. HEC-HMS software has been used for Clark's UH application. Triangular UH runoff calculation has been done using MS Excel environment to establish a series of equations and logical conditions. Both models' results were compared for storms with 5 years, 10 years, 100 years and theoretical maximum return period; thus also for storms with longer return period than is proposed in the regulation. The positive differences in soakaway peak overflows and peak runoffs in study sites before the start of the urbanization were compared and evaluated, together with the differences in soakaway...
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