National Repository of Grey Literature 78 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Division of the region of the Šumava/Böhmerwald Mts. in terms of heavy precipitation
Králová, Kateřina ; Müller, Miloslav (advisor) ; Šobr, Miroslav (referee)
Divison of the region of the Šumava/Böhmerwald Mts. in terms of heavy precipitation Abstract This thesis deals with the spatial and temporal distribution of heavy precipitation in the Šumava region. The first part of the work is devoted to literature review regarding precipitation conditions in mountainous areas and a brief description of the Šumava mountains. The second part is initially devoted to the analysis of a total of 683 heavy precipitation events at the 64 stations spread evenly between Czechia, Germany, and Austria. The 50 largest daily precipitation totals at individual stations in the period 1971-2018 were always selected as strong precipitation events. The analysis was focused on the seasonal division of these events into four periods, namely spring, summer, autumn, and winter. Here, a strong link between the winter period and the westerly flow and the summer period and circulation types B, Bp, SWc and C is shown, and it is also confirmed here that spring and autumn are rather transition periods between the warm and cold part of the year with regard to heavy precipitation. Furthermore, an analysis of strong precipitation events was conducted based on the location of the geographical midpoint of the Tu event in quadrants I-IV, which were defined using the created vector space. I. and IV....
Design precipitation in Czech river basins
Müller, Miloslav ; Kašpar, Marek ; Hulec, Filip
Data on rainfall intensity on the territory of the Czech Republic with a horizontal resolution of 1 km2 and a time step of 10 minutes, obtained by adjusting radar estimates with data from rain gauge stations, were used to derive design areal precipitation in the Czech river basins of 1st to 4th order and in the basins of surface water bodies. When the rainfall accumulation time is doubled, the design precipitation total in individual pixels increases by about 20% on average. The magnitude of the design totals decreases with increasing catchment area, especially for shorter accumulation periods.
Evaluation of the areal extremeness of extreme weather events in Czechia in the period of 1961–2020
Kašpar, Marek ; Müller, Miloslav
Due to the multiplication of impacts of weather extremes when occurring in larger area, we proposed an areal approach of their evaluation. We evaluated six types of extreme weather events, namely, heat waves, cold waves, air temperature drops, windstorms, heavy precipitation, and heavy snowfalls. We employed the original method using the Weather Extremity Index derived from return periods of values of relevant meteorological variables in the affected area. Each event is characterized not only by the areal extremeness quantified with the index but also by the spatial extent and duration. In the studied period, heat and cold\nwaves generally reach higher index values in relation with larger affected area. The increase in the frequency and extremity of heat waves is in contrast with the decrease in the frequency of cold waves and significant heavy snowfalls. The frequency of windstorms is slightly decreasing with the most significant ones concentrated in the cold half-year. Air temperature drops are the most frequent in the warm half-year, nevertheless three of four top events occurred in January. The frequency of heavy precipitation tends to fluctuate. The obtained meteorological database of extreme events may help to estimate the parameters of future ones using climate models.
Comparison of lightning detection networks over Czechia
Pacovská, Lucie ; Popová, Jana (advisor) ; Müller, Miloslav (referee)
This thesis focuses on ground-based lightning detection which is important since lightning discharges still cause casualties yearly worldwide. The thesis provides description of several ground-based lightning detection networks and an analysis of lightning data of three lightning detection networks covering the Czech Republic during 2015 - 2021. Specifically, the data of the World Wide Lightning Location Network (WWLLN), the amateur network Blitzortung and the European network EUropean Cooperation for LIghtning Detection (EUCLID) are investigated. The thesis examines the spatial and temporal characteristics of lightning discharges from the three detection networks, the relationship between lightning discharges and land cover from CORINE Land Cover data, and the relationship of lightning discharges with types of weather situations based on the Czech Hydrometeorological Institute (CHMI) data. The results show that there is not much difference in the temporal and spatial characteristics of lightning discharges among the three detection networks. The relationship between lightning activity and land cover is the same for the three networks. Unlike the relationship between lightning activity and land cover, the relationship between lightning activity and weather types is in good agreement among the...
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...
Extreme cases of snowfall in Czechia
Kolář, Šimon ; Müller, Miloslav (advisor) ; Jeníček, Michal (referee)
The diploma thesis deals with identification and evaluation of extremity by extreme cases of snowfall in Czechia in the period 1961-2019. Identification of extreme events takes on bases from Weather extremity index and maximum depth of fresh snow on weather stations. Extreme events are evaluated with Weather extremity index and Regional Snowfall index in relation to the affected people or with tool of maximum depth of fresh snow. The results of the diploma thesis bring a more comprehensive climatological view of the relatively hitherto neglected issue of the extremity of this winter hydrometeorological hazard in Czechia, but also of the causative synoptic situations leading to these extreme events. The results show a close connection of the point extremity by the events to higher and mountainous locations, which is related to the intensifying windward effect of precipitation. Important from this point of view is the area of the Moravian-Silesian Beskids, which is characterized by the highest number of extreme events, during which the height of the national maximum depth of fresh snow was recorded here. An example of an extreme event was 14th October 2009, when up to 65 cm of depth of fresh snow fell on station Lysá hora in a single day. In the case of area extremity, the link to lower and medium...
Derecho windstorms
Staněk, Miloslav ; Müller, Miloslav (advisor) ; Zacharov, Petr (referee)
Derecho is a widespread windstorm associated with a line of severe convective storms. To be classified as derecho, the windstorm must exhibit wind gusts exceeding 25 m.s-1 on a major axis length more than 400 km, with minimal three wind gusts exceeding 33 m.s-1 . Various mechanisms play a main role in the formation of these widespread windstorms, which interrelate and can together be responsible for the formation of derecho. However, the occurrence of derechos is not only the domain of the USA, but also of Europe, China and South America. Conditions for the formation and development of derechos in Europe are different from those in the USA and their occurence is not concurrently as frequent as in the USA. Warm season derechos in Europe occur at lower instability than derechos in the USA and at higher deep layer wind shear values. In respect of the extent of the damaged area, the cold season derechos in Europe hit larger areas than derechos in the USA. Warm season derechos in Europe are related to the area of the front side of the upper trough and develop ahead of the cold front near the convergence line. Conversely, cold season derechos are related to the significant cold front. One of the most significant warm season windstorms in the Central Europe occurred on 4th July 1929. This event was...
Changes in light pollution during the night
Klauda, Ondřej ; Matějček, Tomáš (advisor) ; Müller, Miloslav (referee)
Light pollution is an environmental problem, the consequences of which include higher level of night sky brightness, negative effects on organisms and natural ecosystems, degradation of quality of life and potential human health problems. Light pollution arises due to improper focusing of luminaires, excessive intensity of artificial light and lighting in unsuitable time. This diploma thesis focuses on changes in light pollution during the night. The main working hypothesis does not assume significant changes in light pollution during the night. The literature review of the diploma thesis describes natural and artificial influences on night sky brightness, temporal changes in light pollution, methods of visualization of light pollution in maps and characteristics of the study area. Within the study area in the Central Bohemia, there were executed measurements of night sky brightness using a Sky Quality Meter. The field stands have been chosen to represent urban, suburban and rural landscape. Based on the analysis of time series of night sky brightness, three types of night sky brightness courses were identified. The most intense changes of night sky brightness were proved in suburban landscape. On the contrary, the least intense changes of night sky brightness were proved in rural landscape....
Comparison of heavy precipitation extremes at the turn of the 19th and the
Brych, Jan ; Müller, Miloslav (advisor) ; Kašpar, Marek (referee)
The purpose of my thesis is to evaluate the extremity of selected precipitation events on territory of the Czech Republic in 1890, 1896, 1897, 1899, 1902 and 1903. I used documented floods to identify specific precipitation events in this period. Individual events were examined by means of the WEI index (weather extremity index) and the frequency of measured precipitation amounts. The most extreme examined event occurred from 27 July to 31 July 1897. Its extremity was also determined by the affected area, which was almost the size of the entire Czech Republic. A very high value of 149 was calculated for the period from 1 September to 4 September 1890. For the events of September 1899, May 1896 and July 1903, the resulting value of WEI was close to the value of 80. The least extreme examined event occurred in June 1902 within a very small affected area (8,630 square kilometres). The recorded value was 25.3 WEI. When comparing the examined events and cases in the years 1961 - 2010 in terms of value of the WEI, I found that the years 1897 (first) and 1890 (fifth) are among the most extreme five years. For comparison, values of the WEI from July 1997, July 1981 and August 2002 were converted into a network of stations that applied to the surveyed years. The results proved the applicability of the WEI...
Time variability of the vertical copmponent of wind speed and its relationship to other meteorological variables in the Czech Republic
Zeman, Šimon ; Kašpar, Marek (advisor) ; Müller, Miloslav (referee)
Title: Time variability of the vertical component of wind speed and its relationship to other meteorological variables in the Czech Republic Author: Bc. Šimon Zeman Department: Physical Geography and Geoecology Supervisor: RNDr. Marek Kašpar, Ph.D. Abstract: The large-scale vertical velocity of the horizontal scale up to thousands of kilometers has been studied in the presented study. These "centimeters" motions have a significant interest in the formation of cloud and precipitation bands in midlatitudes frontal cyclones. The formation and distribution of large-scale vertical motion in the frontal midlatitude cyclone are mentioned. For the statistical analysis, the data from the reanalysis project ECMWF ERA-40 were used for the Czech territory from 1957 - 2002. From March to July, higher frequency of ascend motions was found. In contrast, descent motions dominated. between September and January. Interannual variability of vertical velocity showed increased frequency of descent motions in the period 1972 - 1982 and increasing frequency of ascend motions between 1983 - 1988. Relationship of vertical velocity and high precipitation has a moderate correlation with exponential regression. Relationship of absolute vorticity advection and vertical velocity have a weak negative correlation. Keywords: vertical...

National Repository of Grey Literature : 78 records found   1 - 10nextend  jump to record:
See also: similar author names
11 Muller, M.
8 MÜLLER, Marek
19 MÜLLER, Martin
1 MÜLLER, Miriam
11 Müller, M.
8 Müller, Marek
19 Müller, Martin
6 Müller, Matyáš
2 Müller, Michael
10 Müller, Michal
19 Műller, Martin
Interested in being notified about new results for this query?
Subscribe to the RSS feed.