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Flash floods, characterized by their sudden onset, extreme discharge, short duration, material damage, and human loss, represent a significant natural hazard. Not well covered by standard hydrological observations, flash flood data can primarily be derived from various types of documentary evidence. This evidence served as the main data source for creating a flash flood database for the Czech Republic from 2001 to 2023. This database enabled detailed analysis of different aspects of flash floods. The annual series of 233 flash flood events, 160 flash flood days, and 424 affected municipalities showed significant inter-annual variability but no linear trends. The triggering rainfall that generates flash floods was analyzed with respect to 1–3-hourly and daily precipitation totals and circulation types from the objective classification. While flash floods can occur anywhere, they were more frequently recorded at the foots of mountain slopes, often coinciding with "critical points" where built-up areas meet concentrated surface runoff pathways. The division of material damage caused by flash floods into eight categories indicated that the highest proportion of damage was to streets and communications (24.3 %), to houses (21.7 %), and to their cellars and basements (18.3 %). There were also 36 recorded fatalities. The understanding of flash floods in the Czech Republic aligns generally well with studies of flash floods in other European regions. [ABSTRACT FROM AUTHOR]

Demographic yearbooks of the Czech Republic, prepared by the Czech Statistical Office for the 1919–2022 period, contain official figures on the number of fatalities attributed to excessive natural cold, excessive natural heat, lightning, natural hazards, air pressure changes, and falls on ice or snow, as well as details about the sex and age of the deceased, covering a 104-year period or parts of it. These yearbooks, influenced by evolving international classifications of diseases, tend to underestimate the fatality numbers for excessive natural heat, natural hazards, and air pressure changes in particular. Out of a total of 9259 weather-related fatalities (with a mean annual rate of 89.0 fatalities), 74.9 % were caused by excessive natural cold and 19.3 % by lightning. No trend was identified in natural hazards, whilst statistically significant decreasing trends were found for lightning fatalities and increasing trends for excessive natural cold, excessive natural heat, and falls on ice or snow. Males and seniors aged ≥65 years were the most common sex and age categories affected. The number of fatalities attributed to excessive natural cold has partly increased as a result of the gradually ageing population and the rise in the number of homeless people since the 1990s. A statistically significant relationship between cold-related fatalities and mean January–February and winter (December–February) temperatures was established, evidenced by high negative correlation coefficients. Lightning deaths have notably decreased since the 1970s, primarily due to a significant reduction in the number of people employed in agriculture, an increase in urban population, better weather forecasting, lifestyle changes, and improved medical care. Although there is a significant positive correlation between these fatalities and the number of days with thunderstorms, the relationship is relatively weak. The results obtained for the Czech Republic align well with similar studies in Europe and elsewhere. While the demographic yearbooks cover only a part of weather-related fatalities, their circumstances, and characteristics, combining them with other similar databases is crucial to gain the necessary knowledge usable in risk management for the preservation of human lives. [ABSTRACT FROM AUTHOR]

Demographic yearbooks of the Czech Republic, prepared by the Czech Statistical Office for the period 19192022, contain official figures for the number, gender, and age of fatalities attributed to excessive natural cold, excessive natural heat, lightning, natural disasters, air pressure changes, and falls on ice or snow, covering a 104-year period or its parts. These yearbooks, influenced by evolving international classifications of diseases, tend to underestimate the fatality numbers for excessive natural heat, natural disasters, and especially air pressure changes. Out of a total of 9,259 weather-related fatalities (with a mean annual rate of 89.0 fatalities), 74.9 % were caused by excessive natural cold and 19.3 % by lightning. Except for a zero linear trend in natural disasters, statistically significant decreasing trends were found for lightning fatalities, and increasing trends for excessive natural cold, excessive natural heat, and falls on ice or snow. Males and seniors aged >65 years were the most common gender and age categories affected. The number of fatalities attributed to excessive natural cold has partly increased as a result of the gradually aging population and the rise in the number of homeless people since the 1990s. A statistically significant relationship between cold-related fatalities and mean January-February and winter (December-February) temperatures was established, evidenced by high negative correlation coefficients. Lightning deaths have notably decreased since the 1970s, primarily due to a significant reduction in the number of people employed in agriculture, an increase in urban population, better weather forecasting, lifestyle changes, and improved medical care. Although there is a significant positive correlation between these fatalities and the number of days with thunderstorms, the relationship is relatively weak. The results obtained for the Czech Republic align well with similar studies in Europe and elsewhere. While the demographic yearbooks cover only a part of weather-related fatalities, their circumstances, and characteristics, combining them with other similar databases is crucial to gain necessary knowledge usable in risk management for the preservation of human lives. [ABSTRACT FROM AUTHOR]

Analysis of a long-term temperature variability of mountains has been neglected for a long time. Here we homogenised and reconstructed four temperature series (1961–2020) of selected mountain stations situated above 1000 m representing the area of northern Moravian mountain ridges (the Czech Republic) and their spatiotemporal variability was examined. A statistically significant increase of 10-year linear trends of annual (0.26–0.38), summer/winter half-year and seasonal mean temperatures were found at most stations. Summer (JJA) was detected as the season with the highest mean temperature increase between 1961–1990 and 1991–2020 normal periods (1.5 °C). From the spatial point of view, the climate conditions were becoming warmer faster in higher elevations compared to the lower ones. At all stations, a statistically significant decrease in ice and frost days was observed (−9.1–19.9 and −9.5–16.3, respectively). Moreover, it was proved that the temperature series of a newly established Vysoká hole station are representative enough and comparable with measurements of other meteorological stations in the studied region. This research provided valuable insight into the temperature variability of mountain ridges and the results completed our sparse knowledge about temperature changes in the mountain regions in Central Europe. [ABSTRACT FROM AUTHOR]

The paper sets out the results of an experiment carried out using MASA SWORD simulator to verify the use of the unmanned aerial vehicle (UAV) reconnaissance model during battalion force protection activities. The authors focus particularly on the first phase of the battle—enemy approaching and early reconnaissance. The reconnaissance was planned using the UAV reconnaissance model which is part of the Tactical Decision Support System (TDSS). The aim of the experiment is to verify the possibilities of using the UAV reconnaissance model for battalion-size unit force protection and to compare this model with ordinarily used tactical procedures. The experiment proves the hypothesis defined in the introduction and quantifies some defined variables. Based on the result of the experiment, it is possible to state that UAV reconnaissance has significant impact on the effectiveness of the military mission. Moreover, the simulation environment opens a wide range of possibilities for future research including multiple simulations of the scenario, comparison of achieved results in dependence on the set conditions and variable settings, tailoring tactics for the scenario at hand, and so on. [ABSTRACT FROM AUTHOR]