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Added value of green roofs
Hrachovina, Vojtěch ; Žák,, Antonín (referee) ; Petříček, Tomáš (advisor)
Introduction is focused on analyze green roof like a part of buiding construction, when thesis assembly principles of right proposal green roof layers. Main part describes characteristic properties green roofs at global impact. We get some added values after comparison with classic roof types. Master thesis consists of survey of added values of green roofs in these categories: life cycle assessment, microclima, outdoor climate, water retention. End of thesis devote to psychological effect of green roofs include questionnare about relationship between czech society and green roofs.
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Evaluation of the effect of radiation on evapotranspiration estimates and drought indices
Mairich, Pavel ; Matula, Svatopluk (advisor)
Abstract Evaluation of the effect of radiation on evapotranspiration estimates and drought indices The severity of drought can be inferred from water balance, of which evapotranspiration is a component. The evapotranspiration estimates are often based on the FAO 56 methodology with the net radiation as the main input. Usually, however, the latter is not directly measured. This study investigates to which extent can the direct solar radiation and the long-wave net radiation measurements be replaced by calculation according to FAO 56 with constant or locally optimised radiation coefficients or, for the long-wave net radiation, the coefficients according to Penman (1948). The problem is demonstrated on data from the Solar and Ozone Observatory in Hradec Králové for 2011 and 2012. On average, the estimates of solar radiation are satisfactory even with the standard coefficients and can be improved by local optimisation of the coefficients. The estimates for particular days may considerably differ from reality. The long-wave net radiation estimate according to FAO 56 is, on average, by about 30 % lower than the measured long-wave net radiation or an estimate thereof based on locally optimised or Penman's coefficients, with the average differences between any two of the last three methods much smaller (less than 9 %). The inaccuracy of estimates for particular days is considerable, too. The average reference crop evapotranspiration according to FAO 56 with standard coefficients is therefore considerably higher (by about 15 %) than analogous evapotranspiration obtained from the measured radiation or according to FAO 56 with optimised or Penman's radiation coefficients. The cause is that grass in the observatory was not irrigated. It therefore occasionally suffered from water stress and got overheated. The use of FAO 56 with the radiation inputs measured or calculated using other than the standard radiation coefficients may underestimate the evapotranspiration and the need for irrigation.
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Analysis of water requirements of the field crops in areas with frequent occurrence of drought.
Zábranský, Petr ; Soukup, Josef (advisor) ; Jan, Jan (referee)
Summary
Water resources are an important part of ecosystems. In the water balance of the landscape, the variability of climate, soil factors, as well as high diversity of vegetation play an important role. Evapotranspiration represents a major passive component in the water balance of the basin. Unlike forests, where the water balance is particularly predictable due to the long-term development of the stands, regular crop rotation in agricultural systems and agricultural practices may cause rapid changes in water balance during much shorter time. It may sometimes result in irreversible changes in ecosystems with impact on landscape biodiversity. An understanding of the limiting environmental factors and exact determination of the water demands of plants makepossible not only an improvement of yield parameters, but it is also condition for understanding of the agroecosystems sustainability in the cultural landscape.
Field measurements of actual evapotranspiration were carried out in the period 2007 to 2015 in Velvary (Budihostice) in the Central Bohemia region, 210 m above sea level in the rain shadow area around Slaný territory. In terms of the average annual water balance (CHMI, 2014), the locality is regarded as the area with the difference between the average annual precipitation and annual potential evapotranspiration totals in amount of -200 mm, so the potential evapotranspiration slightly exceeds precipitation. Field measurements were conducted on commonly managed areas with a minimum size of the experimental plots of 1 ha.
The measurements confirmed differences between the crop water demands during the growing season. Different values of the actual evapotranspiration as well as the Bowen ratio values were estimated for the observed crops depending on the growth stage of crops. The lowest values of actual evapotranspiration were detected for Zea mays and Sorghum bicolor. Higher water demands were shown by Triticum aestivum and Hordeum vulgare. On the contrary, the highest values of actual evapotranspiration were found in stands of Beta vulgaris and Medicago sativa. According to the values obtained for crop coefficients (Kc), the crops of Z. mays, S. bicolor and T. aestivum had about a quarter lower values of Kc compared with M. sativa and B. vulgaris crops in the main growing season. In this work, the daily values of Kc, which are the basic characteristics of moisture requirements for individual crop were determined and can be used modelling of hydrological processes in agro-phytocoenoses. The evaluation of moisture requirement of crops by the water flow in plants (determined by the sap flow method) showed the expected differences between S. bicolor and Z. mays plants. Water use efficiency (WUE) was significantly higher in plants of C4 type (Z. mays and S. bicolor) compared with the rest of observed plants of C3 type (T. aestivum and H. vulgare).
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Wood seasoning of poplar Populus maximowiczii x P. nigra ´Max 1-5´ using evapo-transpiration
Švejkar, Tomáš ; Štícha, Václav (advisor) ; Jankovský, Martin (referee)
This thesis deals with the possibility of using evapotranspiration for efficient drying of wood. An important prerequisite is that the trees with good coppice pleated capability even after they are felled and physiologically active until they have enough water in the wood. The physiological activity sheets then accelerates the drying of wood. In search of work deals with familiarization with the problems of drying biomass possibilities of its use, and other definitions associated with this work. The main output of this work is to evaluate the decrease in water content in the wood poplar Populus maximowiczii x Populus nigra 'Max 1-5', chopped down just before the start of the growing season, due to evapotranspiration. In discussing data are compared with other available literature and summarized at the end of everything.
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Agroklimatické hodnocení lokality z pohledu pěstování vinné révy
Macholánová, Lenka
ABSTRACT Agroclimatic site evaluation from the perspective of growing vineyards Grape vine cultivation is significantly limited by climatic conditions. The Czech Republic is located at the very northern edge of the effective vine cultivation. Therefore growers are significantly interested in climatic conditions specification. Software "AgriClim" calculates on the basis of basic meteorological data the selected meteorological and agro-meteorological characteristics related to the cultivation of the vine. Data processing and evaluation was performed for the long-term time series from 1961 to 2009. The aim of research was to assess the absolute values (eg. minimum temperature), computed values (eg. Huglinův index, evapotranspiration) and trends in fifty-year series and answer the question whether the climate is changing and whether changes are in favour of cultivated plants or not. There were three weather stations selected in the vicinity of grapes regions (Lednice, Brno-Turany and Stare Mesto) and two stations located at higher altitudes (Brumov-Bylnice and Boskovice), where the grape vine has so far not been cultivated. There were observed significant increase of temperature in all locations and no changes in precipitation. This situation is negatively reflected in the state of the water balance of the lowest locations that are becoming drier and more risky for grape vine producers. On the other hand grape vine potential is growing at higher altitude locations, which provides nowadays better watering conditions.
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Methods for determining evapotranspiration and its values ??in the Czech Republic
HOUDEK, Tomáš
This paper deals with methods for determining evapotranspiration and its values achieved in the Czech Republic. For a better understanding of these issues is explained in the introduction to the concept of evapotranspiration. The first part of this paper discusses evaporation, its types and division. In this thesis are also presented factors affecting evapotranspiration. The largest part of this search addresses the methods used for determining evapotranspiration. Here we find treated in more detail the direct and indirect methods of estimation. The last part of this paper presents and compares the potential evapotranspiration totals achieved in the Czech Republic on the basis of different numerical methods.
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Non-metabolic use of solar energy in plants
REJŠKOVÁ, Alžběta
Non-metabolic use of solar energy in plants can be seen as plant thermoregulation driven directly by solar irradiance. Adaptations leading to warming up are particularly important in cold habitats. Cooling processes are needed everywhere where there is short-term or long-term excess of solar energy. Plants are of utmost importance for ecosystem and landscape functioning. Vegetation has a potential to regulate the Earth{\crq}s surface temperature and improve conditions for other living organisms. By regulating energy and water fluxes between land surface and the atmosphere vegetation is closely related to the climate system.
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