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Time variabilty of soil hydraulic properties and their impact on soil moisture estimation
Šípek, Václav ; Vlček, Lukáš ; Tesař, Miroslav ; Zelíková, Nikol ; Hnilica, Jan
The study was focused on the temporal variability of saturated hydraulic conductivity in an experimental plot covered by spruce forest and investigated benefits of its incorporation into soil water balance model. The results showed that the higher saturated hydraulic conductivity (33.6-44.8 cm hr-1) was observed in summer period compared to lower values (13.2-22.3 cm hr-1) in the winter period. The use of seasonally variabile saturated hydraulic conductivity improved the efficiency of soil water balance model in terms of lower root mean square error between observed and simulated volumetric soil water content by 33.2 %. The Nash-Sutcliffe coefficient rose from 0.34 to 0.68.
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Hydrology of small basins 2023
Hnilicová, Soňa ; Tesař, Miroslav
The book is a collection of scientific contributions to the Conference "Hydrology of small basins". The conference topics were: 1. Changes in the regime of water resources in small basins; 2. Complex monitoring a and water storage balance in small basins; 3. Hydrological extremes (flash floods, drought); 4. Effect of land use and land cover on water balance; 5. Hydrophobicity and transportation processes in soil; 6. Hydrological modelling und uncertainties; 7. Biogeochemical fluxes in a small watershed and eutrophication of surface waters; 8. Mountainous experimental small basins (deposited precipitation, snow regime, …); 9. New methods, techniques and instrumentation in hydrology and hydroecology.\n
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Character of groundwater flow in highly permeable sediments of Bohemian Cretaceous Basin
Kůrková, Iva ; Bruthans, Jiří (advisor) ; Datel, Josef (referee) ; Tesař, Miroslav (referee)
The study focuses on water flow in sandstones and sandy limestones of the so-called facies transition in the western part of the Bohemian Cretaceous Basin. The area between Turnov, Milovice, Úštěk and Doksy is a part of most important aquifer in the Czech Republic, in terms of water supply. However, there are considerable discrepancies in hydrogeological concepts regarding groundwater flow in this area. The prevailing opinion is that quartz sandstones form the main aquifer, although largest springs are partly located outside the area of their occurrence. The aim of the work is therefore to determine which rocks are the source of the large springs and where diffused seepage predominate. Furthermore, to characterize the possibility of rock karstification, to describe the character of the channels and the flow in them, and at the same time to compare it with the flow in the adjacent porous environment in selected areas. Thermometry (winter profiling of temperature and conductivity along watercourses) was carried out in order to distinguish areas with large springs, diffused seepage and stream segments without any drainage. The karst potential of rocks was determined using calcimetry and adopted leaching tests. To determine flow velocity in karst channels and to characterize the channels, a series of...
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Amount and differences in snow accumulation in the Šumava region
Procházka, J. ; Šustková, V. ; Tesař, Miroslav
The Šumava Mts. (Bohemian Forest) represents the most extensive mountainous range of the Czech Republic and due to its area and altitude it catches the substantial portion of the winter precipitation in the snow form. Unfortunately, the more continuous information on snow characteristics from the highest and remote regions of the Šumava Mts. has been in effect missing till recently. From this reason the activities focused on the more detailed expeditionary field measurements of the snow depths and snow water equivalent. The space analysis of point snow cover measurements the appropriate tools were used: ArcGIS (ESRI), orographical interpolation, LLR methods and the methods of ClidatDEM used in the Czech Hydrometeolological Institute.
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Changes in the ratio between a new snow depth and seasonal precipitation in mountainous and submontane regions of the Czech Republic
Procházka, J. ; Lipina, P. ; Šustková, V. ; Tesař, Miroslav
Snowfall and snow cover formation is an important aspect of the colder part of the year in the Czech Republic and Central Europe. Snow cover is important from the point of view of climatology, hydrology, ecology and recreation, and therefore economic. In addition to precipitation, the amount of new snow depends mainly on the air temperature. With gradual warming, it can be assumed that with a similar total precipitation, the proportion of precipitation in the form of snow and the ability to form snow cover will decrease. In order to evaluate the mentioned changes, the ratio of the seasonal amount of new snow in cm and total precipitation in mm, Sn/P (cm/mm) was used in this paper. For the analysis, data from the CHMI database for two normal periods 1961–1990 and 1991–2020 were processed for selected mountain and foothill meteorological stations in the Czech Republic. The period from November to April was assessed as a cold part of the year for this purpose, when a new snow cover is more likely to form. The results of the study showed that the Sn/P ratio decreased in the period 1991–2020 compared to the period 1961–1990.
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Study of water flow and geochemical processes in the unsaturated zone of carbonate and salt karst
Kamas, Jiří ; Bruthans, Jiří (advisor) ; Tesař, Miroslav (referee) ; Buzek, František (referee)
Water flow and geochemical processes within the unsaturated zone (UZ) in two distinct types of karst environment were investigated using natural tracers (chemistry, stable isotopes 13 C, 18 O, 2 H, and 3 H, 14 C, 87 Sr/86 Sr). The extent of horizontal flow component and the response of drip water chemistry to recharge events were examined in the Moravian Karst (Czech Republic), while the character of water flow and its chemistry were studied in salt diapirs in southeastern part of the Zagros mountains (Iran). Under the conditions of well-developed epikarst, the horizontal flow component, defined as Hmax/T (Hmax = horizontal migration component, T - thickness of VZ) typically reaches values of 0.1 - 0.6 (Moravian and Slovenian Karst). However, in areas where epikarst was stripped off by glacial or human activity, the proportion of horizontal flow component is far greater (Hmax/T 1.6 - 24). This parameter is vital for the design of water source protection zones above caves. Nitrate mean residence time in 120 m thick VZ of the Moravian karst exceeded 16 years. The VZ above the Ochoz Cave (Moravian Karst) represents a semi-open to open system with respect to soil CO2. Under a high drip rate (high flow), the event water only made 5% of the total. During the year, water degassing and so called prior...
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Flow and mean residence time in karst unsaturated zone (Ochoz Cave, Moravian Karst)
Vysoká, Helena ; Bruthans, Jiří (advisor) ; Buzek, František (referee) ; Tesař, Miroslav (referee)
Flow and mean residence time in epikarst and unsaturated zone was studied above the Ochoz cave in the Moravian Karst. I studied various flow components with different residence time in unsaturated zone and the influence of soil and epikarst on seepage composition and residence time by means of several methods (longterm monitoring of conductivity, flowrate of seepage and soil water, use of environmental tracers - 18 O, 3 H, CFC and SF6, flow into the soil and detailed sampling during intesive rain events). Seepage sites Kašna in the Rudické propadání cave system and Mapa Republiky in Býčí skála were reference localities in unsaturated zone. For comparison I modeled residence time in saturated zone: at Kaprálka outlet close to the Ochoz cave, at Stará řeka (Rudické propadání) and Konstantní přítok (Amatérská cave). Mean residence time in unsaturated zone above the Ochoz cave reaches 7 - 20 years, while it is only few months in the soil (1 - 8 months, depending on the depth). At Kašna seepage site, the reasidence time is similar to the Ochoz cave - about 18 - 20 years, at Mapa republiky seepage site, it reaches 150s year due to unusual geological settings. Mean residence time in order of 10 - 20 years corresponds to storativity values (0.6 % in average) calculated from parallel water level recession...
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Soil water regime of reclaimed and unreclaimed post mining heaps
Cejpek, Jiří ; Frouz, Jan (advisor) ; Moldan, Bedřich (referee) ; Tesař, Miroslav (referee)
This PhD thesis compares the water regime of reclaimed and unreclaimed spoil heaps after brown coal mining, with special regard to the development of hydrological properties of soils, which are determinant for the movement and retention of water in the soil. The basic influence on the supply of soil water has the technology of pouring the spoil heaps and aging, which co-regulates the development of vegetation. During the development of soil's spoil heaps increases field water capacity and water retention, but also increases the wilting point. These changes are related to the accumulation of organic matter in the soil and the degradation of claystones to particle size of physical clay. The development of the ability of the spoil heaps soils to bind water is greater in reclaimed areas, where the upper organomineral horizon develops more rapidly, but there is also a wilting point and water consumption. On unreclaimed area, the soil substrate develops more slowly. Overall, the differences in water regime between reclaimed and unreclaimed areas are small.
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