National Repository of Grey Literature 148 records found  1 - 10nextend  jump to record: Search took 0.02 seconds. 
Hydrological drought in the context of climate change: Case study of the Blšanka and Loděnice basins
Burian, Alois ; Janský, Bohumír (advisor) ; Hanel, Martin (referee)
The final thesis deals with the issue of hydrological drought in the context of climate change. The basins of the Blšanka River and the Loděnice River have been suffering from water shortages in recent years, therefore they have been selected for the purposes of this final thesis. The thesis summarizes the basic principles used to estimate climate change on the water resources with emphasis on the occurrence of hydrological drought. At the same time, individual components and processes of hydrological modelling conditioning the formation of affected time series in the near (2020-2050) and far future (2070-2100) are described. A total of sixteen simulations created from the seven global climate models (GCM) of the CMIP5 project and three climate scenarios (RCP; Representative Concentration Pathways) are used. The time series of precipitation and air temperature, which have been influenced by the climate change, were derived by an advanced delta method that counts also with the change of variability. The conceptual hydrological model BILAN is used to simulate changes, due to its availability from the T. G. M. Research Institute of Water Management and its wide use in Czech conditions. The parameters of the BILAN model are calibrated based on the observed time series of both selected river basins....
Snow drought and its importance for runoff in the context of changes in climatic and snow characteristics
Hlavatý, Vojtěch ; Jeníček, Michal (advisor) ; Nedělčev, Ondřej (referee)
Snow drought, defined as a lack of snow accumulation, is one of the consequences of increasing air temperature, which has a considerable impact on the runoff generation as it provides a substantial part of water supplies in the warm season. However, the attention to snow drought has been paid mainly to North America. Therefore, this work aimed to evaluate the current state of research on this topic and to analyze data from the Churáňov station in the Šumava Mountains. Long-term trends in climatic and snow characteristics in the period 1966-2017 were described using linear regression and Mann-Kendall test and relationships between them were examined by correlation coefficients. Consequently, the occurrences of snow drought were classified using different approaches. According to the results, the main cause of interannual changes in snow storage in the Šumava Mountains was the increasing mean cold season air temperature, causing a decrease in snowfall and thus a reduction in the maximum snow water equivalent, which can be intensified by a decrease in cold season precipitation. This was also indicated by the frequency of different types of snow drought, especially an increase in warm snow-poor seasons, which, considering the predicted climate change, highlighted the importance of this phenomenon....
Long-term precipitation changes in Europe in different data sources
Vít, Václav ; Huth, Radan (advisor) ; Crhová, Lenka (referee)
The subject of this diploma thesis is the analysis of long-term changes in precipitation in Europe over the period 1961 - 2011. Emphasis is placed on determining differences in values of trends in precipitation among selected data sources and on analyzing the spatial distribution of annual and seasonal changes in precipitation in Europe, including a discussion of possible causes of differences in these changes in individual areas. Another aim is to illustrate, describe and account for the differences in trend values among different data sources: the ECA&D station database, the interpolation network data sets E-OBS and CRU TS and two reanalyses JRA-55 and NCEP/NCAR. Depending on the amount and quality of data available for the comparison of data sets, changes in precipitation totals were described over a long-term scale in absolute and also, to a lesser degree, in relative values. The first part summarizes the scientific literature dealing with the changes in precipitation characteristics throughout the world and in Europe. There follows a description of the suitability of individual types of data sources for estimating trends in precipitation totals. Scientific articles usually describe long-term changes based on a single data source rather than using a variety of individual types of data sources....
Evaluation of the efficiency of erosion and runoff conditions of a selected catchment areas
Mokrejš, Filip ; Ing. Kateřina Vašinová, Ph.D (referee) ; Dumbrovský, Miroslav (advisor)
The subject of the bachelor's thesis was to evaluate the erosion and runoff conditions in the area of interest and then to design alternative measures to mitigate the impacts of water erosion. Evaluation of erosion conditions was conducted in ArcGIS using hydrologically correct DMT. The runoff conditions were evaluated using the hydrological model DesQ. A variant of climate change and impacts on soil erosion and agriculture is also presented. In conclusion, the effectiveness of individual soil erosion control measures was evaluated.
Study of the cooling system of a building with regard to climate change in the Czech Republic
Vašulka, Tomáš ; Charvát, Pavel (referee) ; Fišer, Jan (advisor)
The diploma thesis aims to prepare a study of the cooling system of a multifunctional building with regard to climate change predicted until the middle of the 21st century. The work includes determining the heat load of refrigerated rooms and designing measures to reduce heat gains in the summer. Diploma thesis includes design of a cooling system with fan-coil units as end appliances with the necessary hydraulic calculations. A single-stage absorption cooling unit is used as the considered cooling source, to which a free cooling heat exchanger is assigned. The design of the cooling source includes the necessary hydraulic calculations and dimensioning of the system ensuring its functional operation. Part of the diploma thesis is drawing documentation of cooling technology and connection of fan-coil units.
Energy and Environment in the View of Law
Pokorný, Jiří
Mankind has come to the point where it is fully dependent on energy. Primarily, this means the universally convertable electricity and also the thermal energy. The most widespread technologies for production of the above energies are unfortunately based on fossil fuels which, when combusted, produce greenhouse gases. Even though this is not the sole source of these substances, it belongs among the largest ones. The heightened concentration of greenhouse gases in Earth's atmosphere causes climate change which endangers the environment of the whole planet. To make this process stop or at least slow down, it is imperative to implement a wide range of measures to limit the greenhous gases production. Even though such measures will need to be carried out technically, their basis lies in law. The dissertation thesis "Energy and Environment from the Viewpoint of Law" deals with relationships between energy and environment (mostly energetics) and tools of law which can be releavant in this field. They can be found across different levels from international through European to national - Czech - level. From the perspective of applied tools, they incorporate conceptual, administrative and economical approaches. The roles of the respective means is such that the conceptual determine future progress,...
Changes of geochemistry of surface water in selected catchments of the Ore Mountains
Navrátilová, Denisa ; Matoušková, Milada (advisor) ; Benešová, Libuše (referee)
This master thesis focuses on an analysis of surface water chemistry, long-term trends and the impact of drought on changes in concentrations of selected parameters in the upper Svatava, Rolava and Načetínský potok basins located in the Ore Mountains. Research on water quality in mountain spring areas is important, the consequences of various changes can be easily observed there. This work analyses the changes in surface water chemistry and discusses their possible causes, especially the impact of peat bogs and dry episodes. The parameters of water temperature, conductivity, pH, BOD5, COD, TOC, concentration of nitrate nitrogen, total phosphorus, phosphates, sodium, potassium, calcium and iron were investigated for the period 1993-2018. The available data are analysed using evaluation methods according to ČSN 75 7221 as well as box plots, Pearson correlation coefficient, PCA analysis and Mann-Kendall test. The greatest anthropogenic influence exhibited in Svatava, almost all concentrations reached their highest values there. In the Rolava and Načetínský potok basins, the influence of peatlands manifested itself by increasing the concentrations of iron, TOC and COD. The results of trends showed an increase both in pH and in surface water temperature related to an increase in air temperature, on the...
Changes in epiphytic lichen biota in the Czech Republic with emphasis on current situation
Hronová, Nikola ; Malíček, Jiří (advisor) ; Palice, Zdeněk (referee)
During the last two centuries a significant change of lichen communities has happened in the Czech Republic. Important factors which had influencing the lichen biota in the past and recently are summarized in this bachelor thesis. Acid rain caused by high imissions of SO2 a NOx was the most important factors of change of species and remaining acidification of substrates is still influencing lichen communities. Until the end of 80's of 20th century acid rain was a dominant factor influencing lichens. Afterwards, thanks to drop of its intensity in 90's of 20th eutrophication and availability of nitrogen in landscape became dominant influencing factors. All these factors mainly affected the communities of macrolichens, and especially cyanolichens to such an extent that some species in the Czech Republic became extinct. Recently the increasing availability of nutrients has been supporting the spread of nitrophilous species. Due to decrease of SO2 emissions to values from the end of 19th century some areas have been recolonized and some endangered species have returned. The transformation of lichen communities has also been significantly affected by forest management and land use. Based on changing climate and change of natural habitats a further decline mainly of suboceanic species is expected. A more...
Systém sledování a hodnocení zranitelnosti vůči dopadům změny klimatu v podmínkách ČR
Kochová, Tereza ; Havránek, Miroslav
Česká republika se podobně jako ostatní země světa potýká s jednotlivými projevy změny klimatu. Změna klimatu je komplexní fenomén, jehož projevy ovlivňují téměř všechny hospodářské oblasti, lidskou společnost i ekosystémy. Reálný efekt daného projevu změny klimatu přitom záleží nejen na místně specifické intenzitě samotného projevu, ale také na tom, zda jsou v zasaženém systému přítomny prvky, které jsou tímto projevem negativně ovlivněny. Reálné efekty daného projevu a jejich závažnost jsou určeny také schopností dotčeného systému dopad projevu předvídat (být na něj připraven), reagovat na něj a přizpůsobit se nastalé změně, případně schopností tlumit negativní dopady a způsobené škody nahradit.
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