Analýza srážkových řad z hlediska vlivu srážek na vodní erozi

The objective of this study was to process long-term daily rainfall data in a comprehensive way (1961 -- 2013) collected from eight selected meteorological stations operated by the Brno branch of the Czech Hydrometeorological Institute, mainly in terms of the potential erosion efficiency. Therefore, special attention was paid to rainy days with rainfall above 10 mm and yearly extreme one-day rainfalls. The determined data was used to analyze N-year design rainfall of various recurrence intervals and to assess suitable determination methods. The secondary objective was to analyze the distribution of rainfall intensities and erosion efficiency of rainfall (the so-called R factor) in the area of Brno, based on ten-year ombrograph records (2003 -- 2012) from 14 stations of Brněnské vodárny a kanalizace, a.s. High spatial variability in the occurrence of heavy rainfalls in a relatively small city area was identified indicating the necessity of the greatest possible level of regionalization in determining R factor in the territory of the Czech Republic

Antecedent precipitation index evaluation at chosen climatological stations

The water retention capacity of a landscape, usually measured for a catchment basin, is a very important and decisive characteristic to identify the runoff amount from the catchment area and, in consequence, for antierosion and flood protection measures. Besides, creating water reserves in the landscape and keeping the water in them is also rather important.Soil humidity contributes to the calculation of potential water retention through modelling the runoff amount and peak discharge from the catchment basin within an area not larger than 5–10 km2. This method is based on curve number values (CN), which are tabulated according to hydrological characteristics of soils, land use, vegetation cover, tillage, antierosion measures and soil humidity, estimated as a 5-day sum of preceding precipitation values. This estimation is known as the antecedent precipitation index and it is divided into 3 degrees – I, II, III. Degree I indicates dry soil but still moist enough to till, whereas degree III means that the soil is oversaturated by water from preceding rainfall. Degree II is commonly used in this context as the antecedent precipitation index. The aim of this paper is to obtain real antecedent precipitation index values in given climatological stations (Brno, Dačice, Holešov, Náměšť nad Oslavou, Strážnice, Telč – Kostelní Myslová, Velké Meziříčí, Znojmo – Kuchařovice) for the period of years 1961 – 2009. Daily precipitation sums higher than 30 mm were considered to be the best candidate for such precipitation value since this occurs approximately once a year in studied areas. The occurence of these sums was also analysed for each month within the growing season (April to October). The analysed data was tabulated by climatological stations in order to check the real occurence of all antecedent precipitation index degrees within the studied period.Finally, the effects of different antecedent precipitation index values on the potential water retention capacity of the sample catchment basin were calculated to compare the results

Changes Of A Rural Landscape In Czech Areas Of Different Types

The paper deals with the macrostructural and microstructural landscape changes in six selected microregions in Moravia and eastern Bohemia. Changes of the landscape macrostructure were evaluated based on the statistical data from 1845, 1948, 1990 and 2013. Changes of the landscape microstructure were compared on the base of old maps, aerial images and field experiences. According to the available data the area of an arable land was the largest in 1845. Since then it has been decreasing – more in mountain areas, less in lowland ones where it was replaced by forests, grasslands and urban areas, depending on the vegetation period, physical character and vicinity of urban centres. Results show that the microstructure recorded great changes during the communist period: large expanses of fields, irrigation and drainage measures, windbreaks, non-rural buildings in the countryside. Contemporary changes are connected mostly with urbanisation of the landscape