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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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Modelling runoff processes in experimental Bystřice River catchmet in the Krušné Mountains
Hasa, Martin ; Jeníček, Michal (advisor) ; Šípek, Václav (referee)
This work deals with the modelling of runoff processes in the experimental Bystřice river catchment in the Krušné Mountains. Rainfall-runoff model WaSiM (Topmodel version) was used for this purpose.Objective of this study was modelling snow accumulation and snowmelt in winter periods 2009/2010 and 2010/2011. Sensitivity analysis of TOPMODEL parameters was performed using Monte Carlo and GLUE methodology. Wasim was calibrated manually for 25 and 250 m grid scales and daily timestep. Results of simulations in both spatial scales different spatial scales differed significantly. Better performance of modelling in finer scale wasn't proved in validation of the model. Results of the simulations pointed out uncertainty in model calibration. Rasters of modeled snow water equivalent were also analyzed in selected days representing periods of snow accumulation and snowmelt. The goal was to examine the functioning of used snow model (combination of temperature index method and energy balance method) within the WaSiM frame. Finer scale raster proved to be practical for this purpose It was found that the spatial heterogeneity in the distribution of snow is determined by evapotranspiration and also by effect of radiation correction (in the case of rainfall).Influence of interception and vegetation effects on...
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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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Variability in snow cover conditions at the Čertova louka and the Modré sedlo sites (Krkonoše Mts) during the period 2003-2013
Tryzna, Vojtěch ; Engel, Zbyněk (advisor) ; Jeníček, Michal (referee)
This work summarizes one decade of spatial snow cover distribution research on the highest plateau of Eastern Krkonoše. This research was done in respect to periglacial landforms, which develop on these localities. The research was carried out during winter seasons 2003/2004 until 2012/2013 on Čertova louka meadow and Modré sedlo saddle. The main goal of the study was to analyze spatial snow depth variability during the season. Next goal was to analyze of possible interaction of snow distribution between both localities.The measurement was carried out manually by snow probe within regular net of 141 points. Our data were further compared with snow depth on professional meteorological station near Luční bouda chalet and with regular measurements of mountain rescue guards. As the main indicator of spatial snow distribution during the season was calculated general variability index. The highest values of snow depth were regularly reached at central terrain depression at Čertova louka meadow (max. 570 cm). On the other hand the lowest values were reached on the edge of Modré sedlo saddle (min. 35 cm). The difference between those two localities is also documented by values of general variability index for Čertova louka meadow (97) and for Modré sedlo saddle (33). The greatest values were usually...
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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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Influence of catchment spatial subdivision on the accuracy of the snow accumulation and snowmelt model
Hájková, Barbora ; Jeníček, Michal (advisor) ; Šípek, Václav (referee)
Influence of catchment spatial subdivision on the accuracy of the snow accumulation and snowmelt model Abstract This thesis is focused on influence of catchment spatial subdivision on the accuracy of rainfall-runoff model simulations. A hydrological model HEC-HMS developed by U.S. Army Corps of Engineers was applied in the thesis. Study area includes two experimental catchments; Bystřice River basin and Zlatý Brook basin. Both catchments are located in the Krušné Mountains. The research in catchments has been carried out by the Department of Physical Geography and Geoecology since 2008. The influence of four different horizontal and vertical catchments delineation on runoff simulations was analyzed. The simulations were performed in two two-year periods 11/2008-10/2010 and 11/2010-10/2012. The attention was mainly aimed to snowmelt component of the model, for which temperature index method was chosen. The results of simulations were compared with water stages data measured in catchments outlets and with data from winter field measurements (snow depth and snow water equivalent). The results from both catchments showed that higher accuracy of simulation of the snow water equivalent was reached by dividing the catchments into more elevation zones. However, each of the catchments behaved in different way. The...
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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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Rainfall-runoff regime in the headwater part of the Bystřice River basin
Šedivá, Kateřina ; Jeníček, Michal (advisor) ; Hladíková, Alice (referee)
Rainfall-runoff regime in the headwater part of the Bystřice River Abstract This bachelor thesis deals with the rainfall-runoff regime and analysis of extreme situations in the headwater part of the Bystřice River basin. At first, the area of interest is described in physical and geographical terms and the influences of individual factors on the runoff are mentioned. The text content is documented by maps. The characteristic of rainfall-runoff regime is evaluated by means of runoff variability parameters. The variability is assessed by means of collected data using charts illustrating exceedance probability of average daily discharges in years 2009 and 2010. The flow variations are evaluated on the basis of decile deviations. The distribution of monthly discharges in the Bystřice River is displayed and the monthly flow variability is described in pie graphs separately for hydrological years 2009 and 2010. The monthly balance of the runoff is also evaluated by means of statistical measures of Kr and Cv coefficients. Finally, the runoff regime evaluation is completed with exceedance probability calculation of the mean annual discharge. The assessment of selected extreme events forms an important part of the thesis. Extreme situations are compared with synoptic situations; it contributes to explain causal...
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Temporal and spatial variability of selected runoff episodes in the headstream area of the Blanice River
Kodádková, Iveta ; Kliment, Zdeněk (advisor) ; Jeníček, Michal (referee)
This study is focused on the evaluation of selected rainfall-runoff episodes in terms of temporal and spatial distribution of rainfall and runoff in the upper basin of the Blanice River. HEC - HMS model with two variants of spatial discretization was used to achieve the results of the holistic approach. The main input data was quantitative precipitation estimation, which better assessed the spatial variability of rainfall fields than interpolated ground measurements. The model simulated five episodes. Contrary to expectations, southern headstream area of the basin showed lower coefficient of runoff in comparison with its northern part. Precipitation cores of epizods occurred over the northern part of the basin at the outlet. Outputs from the model were evaluated in relation to measurements carried out in the experimental basin Zbytiny. Key words: Blanice River, HEC-HMS, hydrologic modeling, quantitative precipitation estimation
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Impact of small water reservoirs on the occurrence of extreme runoff episodes in the upper Otava River basin
Šmrhová, Zuzana ; Kocum, Jan (advisor) ; Jeníček, Michal (referee)
The main objective of this thesis is to prove the influence of small water reservoirs on the extreme runoff situations in a watershed of upper Otava River. The system of small water reservoirs represents an effective part of flood protection, which can be realized without greater changes of landscape. The research part of this thesis includes a summary of knowledge about rainfall-runoff process, small water reservoirs and hydrological modeling. The work is applied to model watershed of Roklanský creek, which is situated in a central part of Šumava Mountains. There are a few rain gauges and laser sensors situated in this watershed, whose are needed for the modeling process. The thesis contains a selection of appropriate data and methods for a creation of digital model of terrain. This digital model of terrain is used for creation of most of the parameters, whose are used for modeling of rainfall- runoff process. This modeling is done in hydrological modeling program HEC - HMS (Hydrologic Engineering Center - Hydrologic Modeling System). HEC - HMS is one of the most used simulation programs. The main part of the thesis is a simulation of rainfall-runoff process, applied to two real rainfall-runoff episodes. Next important part of the thesis is a comparison of this simulation with and without...
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