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Use of uranine-probe method to determine evaporation rate from porous media
Pohan, Tomáš ; Slavík, Martin (advisor) ; Mareš, Jakub (referee)
Evaporation from porous media affects many natural processes. In my work, I focused on the second evaporation phase, calculating the evaporation rate using Fick's law based on air temperature and air humidity above the surface, the water-vapor permeability of the porous material, and the evaporation front depth below the surface. To determine this depth, I used the uranine-probe method using sodium fluorescein. The work aimed to calculate the evaporation rate using Fick's law and values of the evaporation front depth determined by the uranine-probe, for 6 sandy soil samples and 3 types of rocks. A sub-goal was to verify the applicability of the uranine-probe for determining the depth of the evaporation front in sandy soil and in 12 different rock samples. Results show successful determination of evaporation front depth for both sand and rocks. The uranine-probe method's accuracy averaged 2.0 mm for sand. The difference in the values determined by the uranine-probe method compared to another, independent method (detection of the evaporation front from the color change of the fluorescein solution) in the sand was on average 1.7 mm, but I did not study this for the rock samples. All evaporation experiments confirmed that the evaporation rate, both measured and calculated, decrease with increasing depth...
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Evaporation from the water surface
Novotný, Eduard ; Šobr, Miroslav (advisor) ; Šuhájková, Petra (referee)
Evaporation and evapotranspiration are significant components of the hydrological cycle. Accurate measurement or calculation of evaporation is essential for studies of water resource development and management, as well as for efficient crop irrigation in agriculture. Throughout history, many models have been developed to calculate potential evapotranspiration based on various meteorological parameters. The accuracy of these models needs to be determined by comparing them with measured evaporation values obtained from an evaporation pan. In this study, 7 models for calculating potential evapotranspiration or evaporation from a free water surface based on air temperature are compared with evaporation measured by the VYPAR-1200 evaporation pan during the evaporation season 2021 at the Vrchlice meteorological station. The most accurate results were obtained with the models presented by Oudin et al. (2010) and Šuhájková et al. (2019), with RMSE values of 1.061 and 1.105 mm/day and MBE of 0.554 and 0.303 mm/day. Even so, the deviations are quite significant and for more accurate calculation of evaporation for the Vrchlice region, parameterization of these models would be necessary. Key words evaporation, water surface, evaporimeter, meteorological station Vrchlice
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Volumetric and Evaporation Analysis of the Landštejn reservoir
Hánová, Karolína ; Bednář, Martin (referee) ; Marton, Daniel (advisor)
This bachelor thesis focuses on the volumetric analysis and estimation of evaporation from the water surface of Landštejn reservoir. The main objective is to determine new bathymetric curves of the reservoir based on the most recent bathymetric survey of the bottom and then to estimate the amount of evaporated water for a selected period. To achieve these objectives, ArcGIS tools will be used to create a digital terrain model that will allow accurate calculation of the bathymetric curves through volumetric analysis. The amount of evaporation will be determined using selected empirical formulas and simple balance analysis, taking into account the standard ČSN 75 2405 concerning the water management design of reservoirs and comparison with data from the Czech Hydrometeorological Institute. The practical part of the work includes the creation and evaluation of a digital terrain model of the Landštejn reservoir and subsequent estimation of evaporation based on average temperatures and other meteorological data. The results show new bathygraphic curves and provide accurate estimates of the volume of water evaporated from the reservoir over the specified period. This work contributes to a better understanding of the hydrological processes in the Landstejn reservoir area and provides important input for more effective water management planning and management.
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Determination of evapotranspiration from small catchments
Toušková, Jitka ; Šípek, Václav (advisor) ; Možný, Martin (referee) ; Brom, Jakub (referee)
Evapotranspiration (ET) plays a significant role in the hydrological balance. The terms potential (PET) and reference (RET) evapotranspiration are often used while estimating its rate. The doctoral thesis deals with the estimation of PET, RET and other selected processes. First, the influence of net longwave radiation (the component of radiation balance) on the rate of PET was examined. It was found that the standard methods result in the significant differences in PET estimation due to the absence of model calibration to local conditions. The original model caused distinction in the PET evaluation for the Liz experimental catchment by up to 100 mm/year. Calibration of the parameters of two commonly used methods for calculating net longwave radiation reduced the error in PET evaluation to less than 20 mm/year. PET or RET estimation itself can be performed by many direct or indirect methods. Their accuracy is highly discussed. This work focused on selection of suitable methods and their further testing on conditions of 18 stations in the Czech Republic. 37 methods were compared with measured data. It was proven, that the best results in this region were achieved by combination methods (with average RMSE of 1.2 mm/day, 18.6 mm/month, and 33.3 mm/year). Among individual models, the radiation-based...
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The design of the small water reservoir
Galuška, Martin ; Hyánková, Eva (referee) ; Doležal, Petr (advisor)
The concept of this work is to assess options of a small water reservoir design on the selected area Bezměrov. Part of the work refers to different types and functions of small dams and their water management solutions. There is a geological survey presented which is describing the composition of the soil layers and investigating available materials for dam constructions. Water balance has been processed for considered dam profiles evaluating specific outflow of the catchment area, vapor and leakage through a simplified design of the dam. That creates a basic conception about possibilities of water manipulation in this area. Based on this evaluation there are several options processed to explore the retention effects of this two small water reservoirs system above Bezmerov locality.
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Urban measures of effective surface water management in urban areas
Vacková, Michaela ; Kročová,, Šárka (referee) ; Polešáková, Marie (referee) ; Urbášková, Hana (referee) ; Kopáčik, Gabriel (advisor)
One of the main challenges in promoting rainwater management into practise is the fact that it was not recognized as an interdisciplinary issue. We should seek ways how to open the problem to other professions, specially for architects and urban planners, who are the key element of its farther development. This work analyzes the reasons of this unsatisfactory state of rainwater management in the Czech Republic and it defines the possible ways how to remedy this state and outlines scenarios of its further development. The default document of the work is czech technical standard "TNV 75 9010 Hospodaření se srážkovými vodami". The new methodological guide, which is part of this work, is based on it. The work extends the range of measures which are mentioned in the standard. It brings new ways for assessing the benefits of the various measures to streamline the application of rainwater management measures in urban space.
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Systems of energy efficient buildings
Šlampová, Kateřina ; Horák, Petr (referee) ; Počinková, Marcela (advisor)
The topic of this diploma thesis is systems of energy efficient buildings with a focus on the building envelope. The first theoretical part describes the quantities that we consider when designing the building envelope. The second half of the theoretical part is with reference to the experimental part of the thesis focused on a special type of vertical perimeter structure, namely walls with live vegetation installed from the outside of the structure. The second, practical part of this work, deals with the design of heating and hot water supply for a multifunctional building. The design is elaborated in two variants - heating by means of radiators in the first variant and in the second variant by means of floor heating for residential units of the solved building. The third part define an experiment, which had the task of comparing the measured quantities on two types of vertical perimeter structures, namely a structure with growing greenery from the outside and an identical structure only without a layer of greenery. At the same time, the task was to check the possible influence of the applied greenery on heat losses, and thus the design of the heating system.
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Summary of a potential evapotranspiration calculation methods in the selected river basins
Bedáňová, Jana ; Benáčková, Kateřina (referee) ; Marton, Daniel (advisor)
The master's thesis deals with the research of available methods for calculating potential evapotranspiration and the subsequent application of selected methods. The text part describes general knowledge about evapotranspiration, specific types of vapors from different surfaces (water, soil, vegetation, snow cover, urbanized area). The following are methods of direct measurement, where the types of vapor meters are described, for which types of vapors they are used. Indirect measurement methods for determining potential evapotranspiration and their distribution are also described here. The main part of the research is empirical methods for calculating potential evapotranspiration, here is a selected list of these methods. Furthermore, a practical application of the method according to Thornthwaite, Hargreaves-Samani and Hargreaves-Allen is carried out using data from the Olomouc-Holice precipitation station, the data of which are available from the ČHMÚ portal. Then a comparison of the used calculation methods is made.
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Soil evaporation and its controlling factors
Fröhlich, Lukáš ; Slavík, Martin (advisor) ; Mareš, Jakub (referee)
Evaporation is one of the basic members of water cycle, affecting a wide range of natural processes. The importance of the study of evaporation is even greater under conditions of climate change. This bachelor thesis focuses on soil evaporation and its controlling factors. The way in which water moves in porous media is described, and the terms evaporation, transpiration and evapotranspiration are defined. The division of the soil evaporation process into three phases is described and relative evaporation rates characteristic for the different phases are summarized. The relationship between evaporation and the spatial distribution of moisture inside soil is explained. The influence of internal and external factors on the evaporation rate is then described. It is assessed whether these factors contribute to higher or lower evaporation rates and under which conditions this occurs. It is evaluated whether the degree of influence of these factors is constant or whether it varies according to the circumstances and the evaporation phase in which the factors operate. Key words: evaporation, transpiration, evapotranspiration, evaporation phases, flow of underground water, external and internal factors of evaporation
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Permeability of natural surfaces of Hruba Skala sandstone in rock cities for water vapour and intensity of evaporation
Slavík, Martin ; Bruthans, Jiří (advisor) ; Pavlíková, Milena (referee)
Aim of this study was to describe capillary water and vapor transport in shallow subsurface of Hrubá Skála sandstone in the Bohemian Paradise. I have quantified permeability of Hrubá Skála sandstone for water vapor using "wet cup" method and also capillary water absorption of sandstone drill cores. I have found out general rules of evaporation and rate of evaporation from several sandstone outcrops in real microclimate. Important part of my work was to determine whether surface crust plays some role in studied parameters. Based on my results, permeability of different types of sandstones for water vapor does not vary significantly and surface crust has no effect on rate of water vapor diffusion. Rate of capillary water absorption is reduced by surface crust. Hrubá Skála sandstone is classified as medium or highly absorbing material. I have proved that evaporation from porous medium can be approximated by exponential function. Rate of evaporation is strongly controlled by climatic conditions, especially by relative humidity. Powered by TCPDF (www.tcpdf.org)
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