Air temperature and humidity conditions were monitored in Hradec Králové, Czech Republic, by a network of meteorological stations. Meteorological sensors were placed across a representative variety of urban and suburban environments. The data collected over the 2011–2014 period are analysed in this paper. The data from reference standard meteorological stations were used for comparison and modelling purposes. Air temperatures at the points of interest were successfully modelled using regression relationships. The spatial expression of point measurements of air temperatures was provided by GIS methods in combination with CORINE land cover layer, and satellite thermal images were used to evaluate the significance of these methods. The use of standard climate information has low priority for urban planners. The impact of the urban heat island on city residents and visitors was evaluated using the HUMIDEX index, as it is more understandable for urban planners than temperature conditions as such. The aim of this paper is the modification, description and presentation of urban climate evaluation methods that are easily useable for spatial planning purposes. These methods are based on comprehensible, easily available but quality data and results. This unified methodology forms a theoretical basis for better urban planning policies to mitigate the urban heat island effects.
According to the IPCC it is possible to predict larger weather extremity associated with more frequent occurrence of heat waves. These waves have an impact not only on the health status of the population, on economic, social and environmental spheres, but also on agricultural landscape and production. The paper deals with the issue of climate extremity and addresses mainly the occurrence of characteristic days (tropical, summer, freezing, ice and arctic) and heat waves. The south-eastern Moravia belongs to the warmest regions of the Czech Republic. Since the area is not urban, it is not affected by urban heat islands. Thus, it can be used as a representative area of climate change in terms of weather extremes. Heat wave occurrence and length analysis was performed for the period of 1931–1960 and 1961–2013. In addition, a prospective analysis was carried out for the period of 2021–2100 where the scenario data of the Czech Hydrometeorological Institute were used. Between 1961 and 1990, heat waves appeared from June to September. The prediction for the next two decades shows that heat waves may appear as early as May. Furthermore, the average count of days in heat waves increased from 6.13 days (1961–1990) to 36 days (2071–2100). A statistically significant increase in the annual number of tropical days (from 9 to 20 days) was found in the assessment of characteristic days for the period 1961–2013. A highly conspicuous trend was found in July and a prominent trend was identified in May. A statistically highly significant trend was also observed in the annual number of summer days.
Hana Stŕedová, Tomáš Stŕeda and Jaroslav Rožnovský
Official price of farmland in the Czech Republic is based on land value in different soil and climatic conditions. The paper compares relevant climatic and agroclimatic characteristics used for land appraisement. Characteristics defined in climatic region of estimated pedological ecological unit system for two fifty years period 1901-1950 and 1961-2010 were evaluated. Area of interest includes 53 points distributed within nine broad areas of the Czech Republic. It is evident that the development of climate has an enormous impact on soil fertility. Difference of station average values of air temperature of both fifty years vary from −0.5 to 1.1 ◦ C (mean difference is 0.3 ◦ C) in the case of vegetation period. The shift of precipitation is not so evident as in the case of temperature. The long term change in precipitation distribution within a year is documented by a different shift of annual, vegetation period and non-vegetation period values. Moisture certainty in vegetation period decreases in all cases of broad areas (except one region). All 50year averages of investigated parameters had been changed in 1961-2010 compared to the mean of 1901-1950. This should be taken into account when fixing the official price. Climatic region parameters should be replaced by a more complex “agroclimatological characteristic”, which take into account also the basic pedological and plant characteristics, for example the available water holding capacity.
Hana Stredová, Jaroslav Rožnovský and Tomáš Streda
Predisposition of drought occurrence is based on combined evaluation of above-normal temperatures and below-normal precipitation. According to the weight of the individual categories of extremity, the five degrees of predisposition to drought were determined (degree 1 is the lowest risk, degree 5 is the highest risk). Evaluation of temperature extremity is based on the determination of abnormality in comparison with average value and standard deviation. Individual categories of extremity of precipitation are determined by comparing the individual monthly data with percentile values. Monthly data of homogenized technical series of the Czech Hydrometeorological Institute were evaluated for the years 1961-2010 in two climatologically dry areas (Breclav and Kladno county in the Czech Republic). Fourty-two months were rated risky in Breclav county and fourty-four in Kladno county. The evaluation shows an increase of predisposition to drought, especially after 1990. The highest incidence of degree 5 was recorded in 2001 to 2010 in vegetation season. Subsequently the drought variability as a mean variance of years/season and drought severity as a sum of degree of predisposition to drought of years/season were assessed. A gradual increase of variability and severity from 1961-1970 to 2001-2010 is visible. The lowest values of variability (maximum 2) and severity (maximum 3) in both counties were recorded in winter.
The results were obtained by measurements in 2014 and 2015 in an apple orchard in Starý Lískovec and Těšetice (South Moravia, Czech Republic, Central Europe) into fertile planting of apple trees. The results show that the bark surface temperature during the year slightly differs from the surrounding air temperature. In addition, it is in average a few tenths of a °C higher in the period before the onset of the vegetation and several tenths of a degree lower during vegetation. Causes of these differences appear to be associated with the flow of sap as well as with foliage. Although it can be reasonably assumed that the temperature of the bark surface on the south side will be significantly affected by the global radiation, our measurements did not demonstrate this dependency. It appears that the wind speed had significantly larger influence on the temperature differences in the non-vegetation period as at speeds over 3.5 m s−1, the drop of temperature is so significant that the bark surface is colder than the surrounding air. Comparison of the development of sums of daily and hourly effective temperatures above 10 °C has shown that where daily values do not show significant differences, hourly values differed so prominently that the calculated date of emergence of adult codling moth in the bark surface was approximately one week earlier than with the use of data for air temperatures.
Hana Středová, Bronislava Spáčilová, Jana Podhrázská and Filip Chuchma
The climate of Central Europe, mainly winter seasons with no snow cover at lower altitudes and a spring drought as well, might cause erosion events on heavy-textured soils. The aim of this paper is to define a universal method to identify the potential risk of wind erosion on heavy-textured soils. The categorization of potential wind erosion risk due to meteorological conditions is based on: (i) an evaluation of the number of freeze-thaw episodes forming bare soil surfaces during the cold period of year; and (ii), an evaluation of the number of days with wet soil surfaces during the cold period of year. In the period 2001–2012 (from November to March), episodes with temperature changes from positive to negative and vice versa (thaw-freeze and freeze-thaw cycles) and the effects of wet soil surfaces in connection with aggregate disintegration, are identified. The data are spatially interpolated by GIS tools for areas in the Czech Republic with heavy-textured soils. Blending critical categories is used to locate potential risks. The level of risk is divided into six classes. Those areas identified as potentially most vulnerable are the same localities where the highest number of erosive episodes on heavy-textured soils was documented.
Pedologic-ecological estimation in the Czech Republic (Central Europe) means determination of land agronomic productivity and its economical pricing and is expressed as a five position numeral code and mapped as iso-lines. The first position of the code is the climatic region representing approximately the same conditions for agricultural plant growth and development. This climatic regionalization was based on the climatic data from 1901–1950. Currently, there is the need to update their existing zoning due to the technological progress of measurement and development of climate models including estimation of future climate. The aim of the paper is (i) to apply actual climatic data to climatic regionalization and (ii) to estimate what climatic conditions are relevant for actually valid climatic regions. The original methodology currently enables us to unequivocally classify only 17% of the entire territory of the Czech Republic (and 18% of Czech agricultural land). A substantial part of the territory does not fit neatly into individual climatic regions. Subsequently the actually valid ranges of climatic characteristics of individual climatic regions were determined. The GIS layers of individual climatic variables computed with data from 1961–2010 were one by one covered by GIS layers of individual climatic regions based on data from 1901–1950. Interval ranges of climatic region variables determined in this way are valid for the period 1961–2010. The upper limit of air temperature sum above 10 °C and annual air temperature in most of the climatic regions was significantly shifted up in 1961–2010. An increase in precipitation is noticeable in wet climatic regions. Moisture certainty in vegetation season and probability of dry vegetation are the most problematic in terms of Estimated Pedologic-Ecological Units (EPEU) climatic zoning. This should be taken into account when fixing the official soil price.
Climatic variables defining climatic regions of estimated pedologic-ecological system (EPEU) were calculated based on fifty-year climatic data from 1961 to 2010. Obtained results were subsequently compared to intervals determining individual climatic regions defined by previous climatic data (1901-1950). In many agricultural intense areas sum of air temperature and mean air temperature exceeded upper limit. In terms of precipitation it is especially noticeable in the wet (higher) altitudes. Significant volatility was found for probability of dry periods from April to September. The values of the moisture certainty from April to September for the period 1961-2010 reached to several tens. In the final analysis, the only safe prediction is that the present and future are likely to be very different from the past. It is necessary to take it into account for actualization of EPEU methodology. Among the strongest arguments justifying the need of this actualization is in particular climate development since 1901, technological progress and improved measurement technology as well as automation and development of climate models coupled with simulations of complex characteristics and estimates of future climate. It is evident that the development of climate and other factors have an enormous impact on soil fertility. This should be also taken into consideration when fixing the official price. It is necessary to consider the possible replacement of the existing characteristics by more suitable (for example soil moisture balance). The findings might be summarized in few words: old climatic regions do not reflect actual climatic conditions.
Soil frost and the depth of freezing are important for the plant development and for the building industry as well. The depth of soil frost is estimated directly by soil frost tube and indirectly from diagrams of soil temperature according to the isotherm of 0 ◦ C (zero-isotherm). The soil temperature measurement is often used for evaluation of freezing depth, because the frost tubes measurement is rarely performed. Measurement by frost tube is done once a day at 7 a.m. and soil temperature in 5, 10, 20, 50 and 100 cm is measured in three observation terms at 7 a.m., 2 p.m. and 9 p.m. Data from agroclimatological station Pohoˇrelice (1971-2000) were used for the evaluation. Three specific real cold periods (1978-1979, 1984-1985 and 1990-1991) and mean frost depth and absolute maximal frost depth for the whole period were evaluated. Course of frost, terms of beginning and the end of frost period and the term of maximum freezing assessed by both methods are almost identical in all real evaluated periods. The results show that the soil frost depth measured by soil frost tube is often higher than that estimated from soil temperature diagrams. It might be caused by graphical processing, as soil temperatures are measured only at five given depths and the depth of zero isotherm is determined by their interpolation. The most significant differences between both methods were observed when evaluating average values for the entire period 1971-2000.
Air and rock surface temperature regime was monitored in Kateˇrinsk´a Cave in Moravian Karst (Czech Republic, South Moravia). Highly accurate temperature sensors with data logger were used for air temperature measurement. Rock surface temperature was monitored by infrared thermometer and infrared thermal camera. Statistical and graphical processing and 2D map were carried out. The rock surface and air temperature increase as the distance from the entrance increases. The highest dynamics of interior air temperature (amplitude 14.3 ◦ C) and the lowest average temperature (4.03 ◦ C) were detected near the entrance. At a distance of 10 m from the entrance the minimum rock surface temperature was -8.74 ◦ C and maximum 8.60 ◦ C. Rock temperature amplitude decreases as the distance from the entrance increases (at the distance of 271-280 m reached the minimum value 1.19 ◦ C). The strongest correlation between internal temperature in remote part of the cave and external temperature was found when external data series shifted 22 days backward. Maximum temperatures in remote part are affected by attendance. Maximum daily amplitude (MDA) in remote parts reached up to 0.69 ◦ C while MDA near the entrance (up to 4.27 ◦ C) is caused by external weather.