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Measuring of winter precipitation and derivation of precipitation time series using snow water equivalent at selected stations in the Sumava Mts.
Valešová, Petra ; Jeníček, Michal (advisor) ; Míka, Dominik (referee)
The measurement of winter precipitation is an important part of many scientific fields, but the same time there are many uncertainties in the measurement that can arise from inaccuracy or poor calibration of sensors, rain gauges and the influence of environmental factors. Measurement inaccuracies can be caused by the influence of wind, evaporation from heated rain gauges or clogging of the rain gauge. The aim of this work is to process data measured by a heated tipping bucket rain gauge, a classical rain gauge and snow water equivalent sensors from selected stations in the Sumava Mountains. These measured data are subsequently processed and, in case of failures, supplemented with data from other stations according to the given principles. Cumulative precipitation series for the hydrological years 2016 to 2022 are then compiled from the data thus supplemented. Key words: precipitation, snow water equivalent, snow depth, measuring of precipitation
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Influence of spatial snow distribution on flood course
Kučerová, Dana ; Jeníček, Michal (advisor) ; Langhammer, Jakub (referee)
For the purpose of hydrological forecasting on mountains' and sub-mountains' rivers is important knowledge of distribution of snow water equivalent in the watershed. Submitted thesis therefore deals with comparison of 9 interpolation methods in terms of quality of their forecasting when predicting snow depth and snow water equivalent in watershed Bystřice (127,6 km2 ), which is situated in the northwest of Bohemia in the Ore mountains. Point data of snow depth and snow water equivalent used in interpolation were sampled during an off- road measuring in 17. 2. 2010 at the 14 snow sampling locations. The interpolation methods were: (1) Thiessen's polygons, (2) inverse distance weighting, (3) global polynomial (4) local polynomial (5) radial basis functions, (6) ordinary kriging, (7) cokriging, (8) residual kriging and (9) orographic interpolation. Independent variable-altitude used in the calculation of snow depth and snow water equivalent was used only in the last three listed methods. Predictive ability of interpolation methods was evaluated by using cross-validation and visual comparison of predicted maps. The best prediction ability was provided by residual kriging and orographic interpolation. The geostatistical methods were next in the order. The method of Thiessen's polygons and inverse distance...
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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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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 vegetation on snow accumulation and snow melt
Pevná, Hana ; Jeníček, Michal (advisor) ; Kocum, Jan (referee)
Effect of vegetation on snow accumulation and snow melt Abstract: This bachelor thesis analyzes the impact of physical-geographic factors on the physical properties and characteristics of the development of snow cover. Results published in the literature are compared with those obtained from experimental measurements in the upper Byst ice River basin in the Ore Mountains during the winter 2009/2010. The paper compares the evolution of snow cover for the actual land cover, forest and open areas. The research of literature and research conducted in the Ore Mountains proved that vegetation significantly affects accumulation and melting of the snow. The process of accumulation in the forest is influenced by snowfall interception in the treetops. Melting snow in a forest area slowed absorption and reflection of sunlight in the treetops. The bachelor thesis demonstrates that in the open areas the snow melted faster than in the forest growth. Keywords: snow cover, snow water equivalent, vegetation, Ore Mountains
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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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Using SAR data for wet snow monitoring
Matyáš, Jiří ; Kolář, Jan (advisor) ; Součková, Jana (referee)
Using SAR data for wet snow monitoring Abstract This paper focuses on an existing method of snow information retrieval by means of satellite SAR data. The method was first presented by Malnes and Guneriussen (2002), and has been proven to be capable of sub-pixel classification of wet snow. It is also able to classify dry snow pixels. The classification is based on change detection, so a snow-free reference image is required. Some flaws in this algorithm have been discovered during the work on this paper and are discussed, as well as a possible solution is suggested. I have also proposed a modification of the algorithm which could improve the classification results and tested the modified algorithm. Keywords: SAR, snow cover, remote sensing, wet snow
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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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Use of remote sensing data for snow water content determination
Špátová, Zuzana ; Kolář, Jan (advisor) ; Spazierová, Kateřina (referee)
Use of remote sensing for snow water content determination Abstract The aim of this diploma thesis is an integration of remote sensing to snow water equivalent measurement in Czech Republic conditions. The summary of present information of snow parameters retrieval is presented. For snow water equivalent obtaining, radar differential interferometry technique was chosen. The technique was carried out with seven ERS-2 radar images. The result of processing was finished after coherence images creation because of low coherence value at all interferometric pairs. The low coherence values did not enable next processing. Terms of the negative result are discussed. In the second part of the thesis, connection between snow characteristics and radar backscattering is searched. Dependence between snow moisture and backscattering is demonstrated. Factors, which impact values of backscattering and correlation with snow parameters, are discussed. In order to obtain snow water equivalent, the processing of remote sensed data was carried out for the first time in Czech Republic region. Therefore the negative result is still valuable information. Keywords: snow cover, snow water equivalent, remote sensing, radar interferometry
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Snow water content modelling in small catchments
Němečková, Klára ; Daňhelka, Jan (advisor) ; Bercha, Šimon (referee)
Title: Snow water content modelling in small catchments This work deals with modeling of amount of snow cover, snow water equivalent, respectively, on an experimental catchment in the Jizerské hory Mts. Measuring and modelling of the snow cover is an important part of water management practice from the perspective of reservoir operation and flood management. The first part of this thesis describes physical-geographical characteristics of the Jizerské hory Mts.especially from the climatological and hydrological point of view but also other charakteristics and conditions that may affect the dynamic of snow accumulation and melting are described with detailed focus on the experimental catchment of Černá Desná river - Jezdecká. Two modelling approaches were applied to simulate snow water equivalent (SWE) based on observed precipitation and temperature. Beside the well knowen SNOW17 model a simple method based on heat index was developed in this work and its parameters were calibrated based on measured timeseries of daily average air temperature, daily precipitation and observed SWE for winter periods 2001 to 2009. Both methods provided reasonably accurate estimates of SWE over the tested period, however it was found that the results for winters with extreme conditions (very warm or very cold) are less...
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