National Repository of Grey Literature 108 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
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.
Influence of land cover and altitude on soilmoisturespatio-temporal variability
Šípek, Václav ; Hnilica, Jan ; Tesař, Miroslav
An understanding of spatial and temporal variation of soil moisture is essential for studying other hydrological, biological or chemical soil processes, such as water movement, microbial activity and biogeochemical cycling (Bruckner et al., 1999, Ridolfi et al., 2003). Although the world-wide total amount of water stored in the soil profile is negligible compared to ocean and glacier storages, it represents a crucial variable concerning the water resources and agricultural management. This is valid especially in the context of ongoing shift in climate. Soil water exhibits a tremendous heterogeneity in space and time (Gomez-Plaza et al., 2000). Therefore, spatial and temporal variations of soil moisture have always been the critical issue. The spatial variability is influenced by variety of factors encompassing the topographical effect on lateral water redistribution (Williams et al., 2003), radiation (Grayson et al., 1997, Geroy et al., 2011), soil texture and structure (Famiglietti et al., 1998, Pan and Peters-Lidard, 2008), vegetation (Teuling and Troch, 2005), climate (Lawrence and Hornberger, 2007), precipitation pattern (Keim et al., 2005) and antecedent soil moisture (Rosenbaum et al., 2012). The land use influence on the soil moisture content variation is of complex a character covering several above mentioned factors. However, it is determined namely by the different vegetation cover, which results in different rates of interception and transpiration. It also strongly influences the soil hydraulic properties, i.e. hydraulic conductivity and water retention characteristics (Zhou et al, 2008). Hence, the reaction of an area to a rainfall and also the temporal variability of the soil moisture content might be influenced by the present land cover. Nevertheless, the studies comparing the influence of several land covers in the longer periods are missing. This knowledge would be valuable especially in the context of extreme climatic events that are present nowadays. In central Europe, the period of major floods (1997, 2002, 2013) was followed by serious dry spells (2003, 2011–2012, 2015) (Trnka et al., 2015). This observed hydrological extremity raised the questions of sustainable water management. One of the possible management practices in consideration is represented by the land cover changes intended to hold more water in the landscape and simultaneously to attenuate the rainfall-runoff response. Moreover, previous studies have investigated that spatial and temporal variation of soil water under a certain land use type, and drawing significant research attention is lacking on the differences of dynamics of soil water conditions under different land use types. Thus, it is necessary to understand the comparisons of the dynamics of soil water conditions under different land use types (Niu et al., 2015) The main aim of the presented study is therefore to understand the soil moisture variability in the vegetation season under four different land covers (coniferous/deciduous forest, meadow, grassland). This analysis is conducted in five consecutive years, encompassing both dry and wet periods. The influence of altitude is also studied in the coniferous forest.
Hydrology of a small basin 2017
Brych, Karel ; Tesař, Miroslav
The CD includes the full text of scientific articles. These articles were prepared as the contributions for the Conference with international participation “Hydrology of a small basin 2017” that was held from April 18th to April 20th 2017 in Prague. The Conference was organized by the Institute of Hydrodynamics ASCR in Prague, Institute of Hydrology SAS in Bratislava, the Czech Water Management Society in Prague, Czech Hydrometeorological institute in Prague and Czech Committee for Hydrology. The book was published by the Institute of Hydrodynamics ASCR in Prague in 2017
Extruze a její využití v cereální technologii
Tesař, Miroslav
The aim of study was describe the extrusion and its application in cereal technology. The study contains an overview of the normally used grains and other raw materials. There is also described the principle of extrusion technology applied to specific production conditions. With that is associated manufacturing equipment, extruders, whose parameters are also included in this work. The important part is the changes of raw materials during the extrusion process. The second part about cereal extruded products. The food market offers a wide range of extruded products. Individual products require specific manufacturing processes. This work includes a qualitative assessment of extruded products expanded of my practical own sensory evaluation extruded snacks.
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...
Effect of global climate change on hydrological patterns in headwater catchments
Lamačová, Anna ; Hruška, Jakub (advisor) ; Tesař, Miroslav (referee) ; Kalvová, Jaroslava (referee)
The aims of this theses were (i) to evaluate trends in spring yields in the Czech Republic (period 1971-2007) and trends in runoff from small forested catchments of the GEOMON network during the period 1994-2011, (ii) evaluate the impact of climate change on streamwater chemistry in acid-sensitive catchment (Lysina), and (iii) estimate the impact of anticipated climate change projected according to different CO2 emission scenarios on flow patterns forested (GEOMON) and alpine headwater (Skalnaté Lake) catchments in the periods 2021-2050 and 2071-2100. Significant negative trends on the annual level were observed at 18% of springs while positive trends at only less than 0.5% of 157 tested objects and 4 of 18 regions revealed significant decreasing trend. To these regions belonged the zones of Carpathian Cretaceous and Paleogene sediments in the southeast and northeast of the Czech Republic, the zones of tertiary and Cretaceous basins in the southeast and Proterozoic and Paleozoic crystalline rocks in the central part of the Czech Republic. Most spring yields were decreasing within the summer months June- August (on average 24%) and least between February and April (on average 15%) (Paper I). There were no general patterns found indicating either significant increases or decreases in runoff on either...
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...
Characterization of karst conduits and flow: Use of tracer tests, recession curves and autocorrelation
Vojtěchová, Anna ; Bruthans, Jiří (advisor) ; Buzek, František (referee) ; Tesař, Miroslav (referee)
5. CONCLUSION In frame of present PhD Theses I performed 8 new quantitative tracer tests and processed 26 of quantitative tracer tests realized in different karst areas of the Czech Republic. Calculations of conduit volume based on tracer breakthrough curve was compared with the real volume of the phreatic loop. The best results were obtained for mean transit time, where tracer-test calculations yielded volumes very similar to the volume obtained by direct filling of the loop. It demonstrates that volume estimation by tracer tests may be quite precise for common natural conduits, but results are strongly affected by the breakthrough-curve parameter chosen by the experimenter. .Spring and river flow hydrographs were studied by tools of statistical mathematics such analyses of recession curves, curves of exceeding and autocorrelation function applied on 77 objects (karst and non-karst springs, resurgences and streams). Ratio of maximum to average discharge is between 1.6 and 65. In general lower values belong to spring hydrographs and higher to superficial streams. There is no possibility to determine origin of the spring (karst spring, non-karst spring, karst spring fed by with sinking streams, karst spring fed by autochthonous recharge only. Coefficients of recession curves were calculated. For every...

National Repository of Grey Literature : 108 records found   1 - 10nextend  jump to record:
See also: similar author names
8 TESAŘ, Martin
1 TESAŘ, Michael
4 Tesař, Marek
8 Tesař, Martin
4 Tesař, Michal
1 Tesař, Milan
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