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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....
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Long-term changes in snow depth and snow water equivalent at selected mountain stations in Czechia
Kožíšek, Matěj ; Jeníček, Michal (advisor) ; Nedělčev, Ondřej (referee)
Long-term changes in snow depth and snow water equivalent at selected mountain stations in Czechia This bachelor's thesis deals with the topic of long-term changes of snow cover in the peripheral mountain ranges in the Czech Republic. The first part is a research of foreign and czech literature dealing with changes in the parameters of snow cover depending on climate change and the consequences of these changes on various components of nature. The second part of the work consists of the analysis of climatic data from stations located in the peripheral mountains of the Czech Republic in the period of hydrological years 1980-2014. The mountains included in this research include Šumava (Churáňov, Lenora and Husinec), Jizera Mountains (Bedřichov and Desná), Krkonoše (Harrachov), Orlické Mountains (Deštné and Rokytnice v O. h.) and Moravskoslezské Beskydy (Lysá hora). The statistical Mann-Kendall test is used to evaluate trends. Changes in snow cover have a significant impact on the functioning of many landscape processes and on the life of the population in terms of future water availability and recreation.
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Modelling the impact of seasonal snowpack on summer low flows in mountain catchments
Nedělčev, Ondřej ; Jeníček, Michal (advisor) ; Šípek, Václav (referee)
This thesis analyses the impacts of winter snowpack and subsequent spring and summer liquid precipitation on low flows in the warm season. Meltwater is an important source of groundwater recharge. From groundwater storage streams are donated during summer months. Snow accumulation during cold season is reduced and snowmelt occurs earlier, which is a result of climate change and leads to lower groundwater recharge rates. That is the reason why change in snow cover dynamics affects summer low flows. Main goals of this thesis are to analyse how snow cover affects low flows I warm season and to compare it with impact of spring and summer precipitation. A conceptual runoff model HBV-light has been used to simulate the snow water equivalent (SWE) and streamflow from three mountain catchments. The integrated multi-variable model calibration procedure was used to calibrate the model. The model was used to simulate the snow and streamflow from 1981 to 2014. Besides the mentioned simulation, two hypothetical scenarios have been performed. These two scenarios accounted for reduced spring and summer liquid precipitation. In the first scenario, precipitation after maximum annual SWE was reduced to 75% of the real measured precipitation. In the second scenario, precipitation was reduced to 50% of the real...
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Determination of snow water equivalent from microwave radiometer measurements
Klímová, Tereza ; Kolář, Jan (advisor) ; Potůčková, Markéta (referee)
DETERMINATION OF SNOW WATER EQUIVALENT FROM MICROWAVE RADIOMETER MEASUREMENTS Abstract Snow water equivalent ammount of water in snow and its knowledge helps for example in flood prognostication. This bachelor thesis engages with determination of snow water equivalent from microwave radiometer's data in cooperation with data from ground stations. Norway was choosen because of its good data availability. Microwave radiometer AMSR2 on Japanese satellite GCOM has been used as a basic instrument. For map creation with snow water equivalent method considering differences of two spectral canals and other snow attributes were used. During verification of this method maps from Norwegian Meteorological Institute and EUMETSAT which provils different method in map creation were used. keywords: snow water equivalent, remote sensing, microwave radiometer
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Analysis of snowpack density in mountain catchments in Krušné Mountains and Šumava Mountains
Blšťák, Adam ; Jeníček, Michal (advisor) ; Vlček, Lukáš (referee)
Analysis of snowpack density in mountain catchments in Krušné Mountains and Šumava Mountains Abstract: Mountain catchments are very important sources of fresh water. These areas are characterized with long period of snow cover. The thesis presents analyses of snow density in mountain catchments, focusing mainly on factors and processes influencing its distribution. The data of data recorded in experimental catchments in the Krušné Mountains and the Šumava Mountains through 2010 - 2014 are compared with findings given in different scientific articles and studies. The thesis examines the influence of several factors on snow density. It is first of all the influence of snow depth, as well as the influence of vegetation, the development of density in time, and the development of snowpack density in relation to the snow water equivalent. The results of the research show that snowpack density gradually increases with snow depth. The highest density occurs on open plains and in damaged forests. Density also increases with time. The highest density can be observed towards the end of winter, in March and April. Keywords: snow density, snow depth, snow cover, mountain catchments
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Effect of canopy interception on snow accumulation at selected alpine localities in the Czech Republic
Nedělčev, Ondřej ; Jeníček, Michal (advisor) ; Falátková, Kristýna (referee)
This bachelor thesis analyzes the impact of canopy interception on snow accumulation. In the first part of the thesis, available literature about interception of snowfall on forest canopy is reviewed. In the second part of thesis, the reader is acquainted with the analysis concerning the effects of forest cover on snow accumulation. The thesis compares snow water equivalent under forest stands with different canopy density, under a disturbed forest due to bark beetle forest with snow water equivalent in adjacent open areas. Snow water equivalent in accumulation period in forest is 28% lower than snow water equivalent in open area. Ratio of snow water equivalent in forest to snow water equivalent in open area during accumulation period does not significantly change. Linear regression was used to describe the relationship between snow water equivalent and canopy density. The findings obtained from the regression show that snow water equivalent decreases with increasing canopy density.
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Energy balance of the snowpack: Case study Bystřice River basin (Krušné Mountains)
Matějka, Ondřej ; Jeníček, Michal (advisor) ; Ducháček, Libor (referee)
Energy budged of the snowpack: Case study of the Bystřice River basin (Krušné Mountains) The aim of this thesis is to describe and calculate the energy budget of snowpack which is one of the approach to snowmelt simulation. The focus is on physical basis of the accumulation and melting of the snowpack. The second aim is to select and apply of such a mathematical expression of the energy budged of snow which provides best fits of the available data set from Hřebečná climatological station in Bystřice River basin in Krušné Mountains. Calculation of point snowmelt and rainfall data measured for the winter season 2011/2012 were used to simulate the snow water equivalent. As the main heat flows that affect the melting of snow in the area have been identified flows caused by shortwave radiation and latent heat. The development of heat flows during the winter period in 2011/2012 was founded. Most obvious development is demonstrated by the proportion of short-wave radiation to the total energy budget. The defects of the measurement of daily precipitation amounts and measurements of snow mass were revealed. Therefore the requirement of identifying the causes of incorrect measurements of snow mass at the climatological station Hřebečná was revealed. Key words: snowpack, snowmelt modelling, energy budget of...
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Effect of key factors on dynamics of a snow cover evolution in Šumava Mts. conditions
Fliegl, Ondřej ; Kocum, Jan (advisor) ; Jelínek, Jan (referee)
Master thesis is concerned with the subject of a snow cover dynamics (focused on snow melting) and of the detailed analysis of each physical-geographic factors effect on its character. Knowledges published in the domestic and foreign scientific literature are confronted with the data acquired within a number of expeditionary snow monitoring campaignes carried out during winter periods 2011/2012 a 2012/2013 in headwaters of rivers of Šumava (Šumava Mts., southwestern Czechia). Mobile field survey was done in a number of time horizons within the broadly conceived research in the upper Otava River basin concentrated on the assessment of the retention potential in headstream areas.
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Influence of snow cover on catchment outflow in wooded and unwooded environment
Hintnaus, Ivo ; Kliment, Zdeněk (advisor) ; Jeníček, Michal (referee)
This work deals with the evaluation of snow cover and snow spatial distribution in experimental Zbytinský and Tetřivči stream basin. Snow mesaurements were focused on snow depth and a snow water equivalent. Interpolation metods and detailed monitoring of rainfall-flow process were applied in the period of the winter half-year 2009 - 2011. The effects of geografic factors on spatial distribution of snow cover in the accumulation period and in the snow melting period were analysed. The analysis of physical geografic factors effect was focused on vegetation, exposure, slope, wind flow and shading. Results confirmed the strong effect of vegetation in the accumulation and snow melting period. Other physical geografic effects on spatial distribution of snow cover were not so significant. The model HEC-HMS was applied to determine the runoff in both stream basins. Simulations result in the winter half-year period reached good agreement between observed and simulated hydrographs. Effects of snow cover contribution to runoff in the snow melting period in wooded Tetřívčí stream basin and also in antropogenic Zbytinský stream basin were proved based on simulations of outflow and snow water equivalent. Key words: snow depth, snow water equivalent, HEC-HMS, Blanice River basin, Zbytinský stream, Tetřívčí stream
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Effect of selected physical-geographical factors on the snow accumulation and snow melt
Pevná, Hana ; Jeníček, Michal (advisor) ; Langhammer, Jakub (referee)
Effect of selected physical-geographical factors on the snow accumulation and snow melt Abstract: This master thesis analyzes the influence of physical-geographical factors on spatial distribution of snow water equivalent, and its evolution. In this work, emphasis is placed on describing the influence of vegetation, aspect and altitude. Measurement was carried out in experimental catchments Zlatý Brook and Bystřice River in western part of the Ore Mountains in winters 2008/2009, 2009/2010, 2010/2011 and 2011/2012. To evaluate the influence of these factors on value of snow water equivalent there was used one of the methods of multivariate statistical analysis - cluster analysis. The research shows that the greatest influence on the distribution and evolution of snow water equivalent in the experimental basins has vegetation and some dependency was proved also between the points of southern exposure. The measurement results demonstrate the suitability of cluster analysis for analyzing the data of point values of snow water equivalent. On the other hand the results showed the main limits of this method, especially the need for a large number of points with different characteristics. The results of measurements and statistical analysis are compared with results published in technical literature. Keywords: snow...
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