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Changes in the ratio between a new snow depth and seasonal precipitation in mountainous and submontane regions of the Czech Republic
Procházka, J. ; Lipina, P. ; Šustková, V. ; Tesař, Miroslav
Snowfall and snow cover formation is an important aspect of the colder part of the year in the Czech Republic and Central Europe. Snow cover is important from the point of view of climatology, hydrology, ecology and recreation, and therefore economic. In addition to precipitation, the amount of new snow depends mainly on the air temperature. With gradual warming, it can be assumed that with a similar total precipitation, the proportion of precipitation in the form of snow and the ability to form snow cover will decrease. In order to evaluate the mentioned changes, the ratio of the seasonal amount of new snow in cm and total precipitation in mm, Sn/P (cm/mm) was used in this paper. For the analysis, data from the CHMI database for two normal periods 1961–1990 and 1991–2020 were processed for selected mountain and foothill meteorological stations in the Czech Republic. The period from November to April was assessed as a cold part of the year for this purpose, when a new snow cover is more likely to form. The results of the study showed that the Sn/P ratio decreased in the period 1991–2020 compared to the period 1961–1990.
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Possibilities of perfluorinated organic compounds (PFCs) removal in drinking water treatment plants and their occurrence in drinking water sources in the Czech Republic
Čermáková, Lenka ; Fialová, Kateřina ; Prokopová, Michaela ; Semerád, Jaroslav ; Petříček, Radim ; Pivokonská, Lenka ; Cajthaml, Tomáš ; Pivokonský, Martin
This summary research report was implemented within the project TAČR TJ04000212 program to support applied research ZÉTA „Possibilities of perfluorinated organic compounds (PFCs) removal in drinking water treatment plants and their occurrence in drinking water sources in the Czech Republic“. This report is addressed to water treatment plant operators and serves as a basic material for optimizing the coagulation / flocculation and adsorption process in water treatment. The report explains in detail the issue of removal of perfluorinated organic substances (PFCs) in water treatment, especially the process of adsorption in pilot plant conditions. This report will be used as a theoretical basis for the operation of the water treatment plant in Kutná Hora operated by the Water Management Company Vrchlice - Maleč, a. s.
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Report on the hydroledological survey in the Černý Důl, Krkonoše Mts.
Šípek, Václav ; Vlček, Lukáš ; Zelíková, Nikol
The report documents results of hydropedological survey in the Černý Důl, Krkonoše Mts. Two experimental sites were selected based on the requirements of National Park Krkonoše with the aim to determine the effect of bark beetle outbreak on the soil water regime. The report contains description of soil hydraulic properties at two plots (healthy and impacted forest) for several soil horizons which will serve as a basis for hydropedological model.\n
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Experimental validation of granular flow kinetic theory under turbulent flow conditions
Haidl, Jan ; Chára, Zdeněk ; Matoušek, Václav
The mixed classical and extended kinetic theory of granular ows is used for modeling the characteristics of particles-water turbulent sheet ow. The open-source solver sedFoam v3.1 is used for the 1-D and 2-D ow simulations. The simulation results are compared to the experimental data measured in the open channel. After that, the simulation parameters are optimized to achieve the best possible agreement between the simulation and the experimental results. The unsatisfactory performance of the KT models and the observed simulation instabilities are discussed.
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Analysis of the flow of a bimodal suspension at the pipe wall
Chára, Zdeněk ; Matoušek, Václav ; Novotný, Jakub ; Konfršt, Jiří
In the paper, the attention is focused on the flow of bimodal suspensions, where the coarse fraction is combined with the fine fraction with the resulting effect of reducing the total pressure losses. Using the PIV and PTV methods, the flow at the bottom of the pipe is analyzed. Using this approach, the velocities of both the bimodal mixture and the individual particle velocities of the coarse fraction were obtained. The velocities of the coarse particles were higher than the velocities of the fine fraction.
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Analysis of precipitation regime in Šumava Mountains
Šípek, Václav ; Zelíková, Nikol
The analysis is focused on the description of precipitation regime in the Šumava National Park in comparison with other mountain ranges in the Czech Republic. The period of interest comprised the years 2001-2019. The daily and monthly precipitation amounts were compared to the reference period covering the years of 1971-2000.
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