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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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Water Balance Hydrological Models Method Comparison
Štolfa, Filip ; Bednář, Martin (referee) ; Marton, Daniel (advisor)
In this work, two types of lumped balance precipitation-runoff models were compiled, from which the model taken from the Sicilian regional climate model was subsequently modified and these modifications were compared with other models. The practical application was carried out in the Svratka river basin above the Vír reservoir ending in the final profile of Dalečín. The input data from this river basin were precipitation totals, average temperatures and flows in the final profile, from which the calculation was subsequently performed in a monthly step. The individual models were compiled in two variants differing in the length of the time series and the number of regression coefficients. All assembled models were subsequently calibrated using four calibration criteria, for which the effectiveness was verified during validation by one common criterion. At the end of the work, individual models and calibration criteria are compared.
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General Runoff Water Balance Model of a River Basin
Černý, Vojtěch ; Knoppová, Kateřina (referee) ; Marton, Daniel (advisor)
Modelling of the rainfall-runoff process is one of the basic scientific skills in hydrology. Rainfall-runoff modelling can help to improve water management, handling of the reservoir's storage volume, or also to facilitate adaptation to current climatic conditions. The aim of the diploma thesis is to create a functional rainfall-runoff model on the basis of water balance equations based on the lumped water balance principle of the hydrological model. Several modifications of the general rainfall-runoff model are approached in the diploma thesis. Four types of the daily evapotranspiration determination are used in the calculations. The rainfall-runoff model is compiled from temperature data and precipitation totals in a daily step. The practical application is carried out on a sub-basin of the river Dyje, which is located above Vranov water reservoir. The main output is a series of daily flow rates that were obtained from calibrated rainfall-runoff models. The best rainfall-runoff model takes into account the water from snow cover melting, the value of the Nash Sutcliffe calibration criterion of this model is 0.608. Finally, the hydrological simulation for the period 2021-2060 is performed in the diploma thesis.
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Analysis of temperature and humidity processes in intensive vegetation roof layers
Sukopová, Dáša ; Solař, Jaroslav (referee) ; Mohelníková, Jitka (referee) ; Vlček, Milan (advisor)
The presented dissertation deals with the analysis of temperature and humidity processes taking place in the layers of an intensive vegetation roof with a larger layer of soil - the roof garden. The aim of my dissertation is to provide more accurate information for the design of the roof covering using the properties and benefits of the vegetation layer of the roof garden. One of the most important advantages of roof gardens is the cooling effect of the vegetation formation in the hot summer season. The work also deals with the idea of wider use of roof gardens for the so-called rooftop farming, which is becoming more and more popular in the world. Otherwise, unused roof areas can make up for the lack of areas for gardens, which are especially lacking in big cities.
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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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Effluent-free treatment plant technology for small wastewater producers
Škarpa, Pavel ; Němcová, Miroslava Pumprlová (referee) ; Kriška-Dunajský, Michal (advisor)
The work aims to find new ways to dispose of wastewater. The theoretical part covers the currently known procedures for the discharge of treated wastewater into surface or groundwater, as well as the balancing of wastewater after previous accumulation. Furthermore, the theoretical part summarises the legislation of the Czech Republic concerning wastewater disposal. The measurement part deals with a new potential option, a sump with upstream water treatment. If the treatment is carried out on the principle of natural wastewater treatment, the volume of water can be reduced by evapotranspiration. Therefore, the aim of this work is to determine the realistic evapotranspiration of a vertical filter, to find a design methodology for a vertical filter to achieve optimal evapotranspiration and a suitable technological arrangement. Another objective is to use long-term air temperature records available from the Czech Hydrometeorological Institute database. The average daily evapotranspiration measured on the laboratory model reached a value of 4.5 mm/day in September 2021. In March 2022 it reached almost 2 mm/day. The equations for determining the potential evapotranspiration applied in the calculation part of the work achieved the highest agreement of 67.5% with the evapotranspiration measured on the laboratory model and will therefore be further developed to achieve much higher reliability of the calculation.
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Hodnocení vlhkosti půdy na stanovištích protierozních opatření s výsadbami dřevin v kontextu intenzivně obhospodařované krajiny
Slezák, Vojtěch
Grassy linear elements with tree planting are an effective tool for reducing the erosion risk of agricultural land on sloping arable land. The research on the deve-lopment of soil moisture during one vegetation season in intensively productive areas on transects of arable land above anti-erosion measures, below anti-erosion measures, and anti-erosion measures themselves was conducted as part of this thesis. Soil moisture was measured in 14day intervals using Electric impedance spectrometry (EIS) from March to October. Soil analyses were also carried out at the study sites. The research results showed that lower soil moisture occurred at the site with anti-erosion measures compared to sites with arable land after the main crop was harvested. These results suggest that the main factor moderating soil moisture between study sites was plant water transpiration. Furthermore, it can be inferred from the results, assuming other research, that anti-erosion measures have a higher infiltration capacity due to preferential water flow pathways.
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Environmental assessment of the Czech Republic based on Water Footprint
Žlábková, Jana ; Hák, Tomáš (advisor) ; Vačkář, David (referee)
This dissertation sets its goal in application of the water footprint indicator, which is a practical and multi-layered indicator of water sources consumption. Of human activities, agriculture presents the most significant demands on water sources consumption. Therefore I have turned my focus to the widely-discussed issue of biofuels production, because the input materials for production of this kind of energy are agricultural crops (in the Czech republic those are: oilseed rape, sugar beet, Indian corn and winter wheat). The calculated results of water footprints of the selected industrial crops (m3 /t) and of water footprints of the heating value units of that crops (m3 /GJ) offer us a concrete notion of energy requirements of water of that chosen industrial crops in the conditions of the Czech republic. Keywords: water footprint indicator, biofuels, oilseed rape, water consumption, biodiesel, bioethanol, evapotranspiration.
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The influence of evapotranspiration on the groundwater of floodplain forests: Libický luh
Vašková, Hana ; Weiss, Tomáš (advisor) ; Slavík, Martin (referee)
The recherche part of this bachelor thesis deals with evapotranspiration from floodplain forests and its influence on the depth of the groundwater level and mineralization of groundwater. As floodplain forests in the Czech Republic are represented only in smaller fragments, there is a mention of the effect of mineralization on plants. The thesis describes the principle and use of stable isotopes in hydrogeology and the comprehensive characteristics of the area of interest of the experimental part, the Libický luh National Nature Reserve. The experimental part includes the observation of the level, conductivity, temperature, pH, and determination of the isotopic composition of the underground and surface water in Libický luh, where high mineralization of the groundwater was previously detected. The thesis discusses the effect of evapotranspiration on the content of dissolved substances in the water in Libický luh as a possible cause of this phenomenon. It was found that as the temperature rises, the groundwater level drops, and that mineralization remains relatively constant throughout the year. The drop in the groundwater level is evidently caused by intensive evapotranspiration from the floodplain forest during the growing season. However, longer time series of conductivity or hydrochemical...
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Evapotranspiration of peat soils
Urbánková, Karolína ; Weiss, Tomáš (advisor) ; Šípek, Václav (referee)
The correct determination of evapotranspiration is critical for the calculation of the water balance. Although research on evapotranspiration in general is already quite advanced, peat soils are so specific that they may require their own unique approach. Hydrologists have a series of calculations and models to determine evapotranspiration, but these are not always sufficiently accurate, especially at higher temperatures. The aim of this thesis was to summarise the existing knowledge of evapotranspiration in peat soils and to determine whether the peat layer thickness has an effect on peat evaporation. The thesis presents a survey of methods for determining evapotranspiration that can be applied to peat soils. The laboratory experiment used a split container, one part of which contained peat and the other part had peat only in the top 7 cm, with quartz sand underneath. The two parts were joined at the bottom with gravel and thus permeable to water. The trend of water loss, soil water potential and soil moisture was monitored. Preliminary results show that peat strength has a clear effect on evaporation. Further research would, among other things, look for a specific height of the peat layer for which the underlying material would no longer have an effect. Key words: evapotranspiration, peat,...
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