National Repository of Grey Literature 61 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
The effect of artificial drainage on the flow of water and other ecosystem functions
Kešner, Michal ; Frouz, Jan (advisor) ; Šír, Miloslav (referee)
The aim of this thesis is to summarize the current knowledge about the changes of soil caused by the subsurface tile drainage. It also deals with a uestion of the influence on other parts which are closely connected, as water, atmosphere and organisms. Foreign and domestic literature suggests that tile drainage by accelerates discharge from the watershed decreases groundwater level and drainage water influences the quality of surface water. It also changes the structure of soil, mainly reducting and anaerobic processes are replaced by oxidative and aerobic ones and all these decrease the amount of soil organic matter. Leaching of nutrients is observed from soil to drainage water. Original ecosystem changes and the composition of organisms shifts as well. But the biodiversity of location does not have to be affected. However, a reducing value of betadiversity may appear in broader context, community composition of original wetland is getting closer to surrounding ecosystems eventually. Due to close connections of all parts of the system, an impact on climate can occur. Knowledge achieved during the development of this thesis should be used in the research about the impact of tile drainage near village Senotín.
Saturation overshoot as a basis for emergent flow phenomena in unsaturated homogeneous porous media
Fürst, T. ; Vodák, R. ; Šír, Miloslav ; Tesař, Miroslav
Understanding and description of fluid motion in unsaturated porous media rates among the most challenging and still not fully resolved problems. Traditionally, porous media flows were described by the continuum mechanics apparatus [1]. The continuum mechanics based models lead to partial differential equations which are mathematical formulations of the balance of mass, momentum, and energy. The most celebrated model is the so called Richards’ Equation (RE) [2]. Other continuum models (see [3], [4] and the reference and discussion therein) are various extensions built on similar principles as the RE.
Long-term hydroecological monitoring in the Krkonoše Mts
Tesař, Miroslav ; Šír, Miloslav
The cloud and fog water deposition proved to be important delivery mechanism for both water and pollutants in mountainous headwater regions. A fogwater study has been conducted in the Krkonoše Mts. since 1999 till the present time. The sampling site for the observation and evaluation occult precipitation in the Western region was established in the Modrý potok basin (1010–1554 m a.s.l., 2.62 km2) at the highest point of the watershed (passive cloud and fog water collector) while the bulk precipitation and throughfall samplers were installed near to the closure profile of the basin. Rain gauges are evenly situated at six altitudes of the watershed (from 1020 to 1365 m a. s. l.). In the Eastern region the both passive and active collectors were installed close to the Labská bouda chalet (1325 m a.s.l). The active collector (Eigenbrodt, Germany) is operated automatically by the PWD-11 sensor (Vaisala, Finland). Collected samples were stored in polyethylene bottles and transported as soon as possible to the laboratories of the Czech Geological Survey and Geological Institute of ASCR to the chemical analyses. The results for 1999–2011 will be presented in this article. A wide range of concentrations were encountered, most typically exceeding concentrations occurring in rain (so-called enrichment factors were evaluated) and the estimated wet deposition of the most important chemical compounds were calculated and compared with respect to weighted means of bulk precipitation collected in the open area. Based on the model predictions and on the water balance of the forest canopy the annual occult precipitation total for the Krkonoše Mts. was estimated by 20–25 % of the annual falling precipitation total. The research is supported by the Czech Science Foundation (205/09/1918).
Early warning system for flash floods in the Krkonoše Mts
Tesař, Miroslav ; Šír, Miloslav
The present contribution describes a sophisticated local warning system (LWS) for detection of local flash floods that is built in the Krkonoše Mts. in the upper of the Úpa river with the closing profile at Horní Maršov (573–1602 m a.s.l., 81.70 km2). This system is based on the new knowledge of the discontinuous character of water transport in an unsaturated zone and involves: (i) instrumentation: (1) stream gauge monitoring stations with data transfer to the internet, (2) monitoring stations (equipped by rain gauge, air and soil thermometers, soil water tensiometers and soil moisture meters) with data transfer to the internet, (ii) software: (1) the internal software of the stream gauge and monitoring stations for the measurement, storage and transfer the data to the dispatching centre, (2) software of a central data repository, (3) software for data transmission in the internet browser, (3) software for the forecasting of flood risk and sending flood alert, (iii) dispatching centre: (1) operating of the data repository, (2) forecasting of the water level for the each of connected stream gauge station, (3) sending flood alert, (iv) handbooks and user’s Guides: (1) hydrological and soil surveying, (2) LWS design, (3) operation and maintenance of the LWS, (v) complete projection documentation of the LWS, (vi) installation of the LWS in a catchment, (vii) testing and routine operation of the LWS. The described LWS is supported by the Technology Agency of the Czech Republic (Project TA02021451).
Extreme runoffs from the Modrý důl basin in the vegetation season
Šír, Miloslav ; Tesař, Miroslav ; Dvořák, Igor
The main objective of the present article is to advance understanding of the complex role of various vegetation cover in extreme runoff formation in the Modrý potok basin. This watershed (1010–1554 m a.s.l., 2.62 km2) is situated in the northern part of the Czech Republic in the eastern part of the Krkonoše Mts. The soil types are the mountainous Podzole and Lithosol with a thin humic layer on crystalline bedrock. Monitoring stations with data transfer to the internet are installed on several localities differing in the type of vegetation cover (in the grassland and dwarf pine above the forest margin, in the growth of mature spruce forest, and in the grassland below the spruce forest). The discharge at the closing profile is continuously recorded. Meteorological data are collected at a station close to the Výrovka chalet (1360 m a.s.l.): year-round precipitation, solar radiation, wind speed and direction, air and soil temperatures and soil moisture. The long-term monitoring of the water balance of the headwater catchment Modrý potok and its soil water regime was evaluated taking into account the discontinuous character of water transport in an unsaturated zone. Extreme runoffs in a vegetation season are caused by these factors: (1) oversaturation of the soil profile, (2) water repellency of the soil surface, (3) gravitationally destabilized flow of water in the soil profile, (4) extreme rainfall. The typical combinations are (1) and (3) – gravitationally destabilized flow of water can be caused even by a small rainfall under the oversaturation, (2) and (4) – long-term drought can cause the water repellency of the soil surface and the extreme rainfall. The research is supported by the Czech Science Foundation (205/09/1918) and by the Technology Agency of CR (TA02021451).
Effect of the soil water on the formation of floods in August 2002
Tesař, Miroslav ; Šír, Miloslav
This work addresses the evaluation of the long-term measuring of the soil water dynamics in mountain basin in Šumava Mts. And Krkonoše Mts.
Hodnocení vlivu klimatických změn na hydrologickou bilanci a návrh praktických opatření ke zmírnění jejich dopadů: Vliv klimatických změn na vodní režim povodí a půd, jeho modelování a návrh adaptačních opatření - systém včasného varování před náhlými povodněmi
Ústav pro hydrodynamiku AV ČR, Praha ; Česká geologická služba, Praha ; Šípek, Václav ; Němečková, Soňa ; Buchtele, Josef ; Šír, Miloslav ; Tesař, Miroslav
Předkládaná studie přináší popis sofistikovaného lokálního varovného systému (LVS) vybudovaného za použití nejnovějších poznatků o hydrodynamických mechanismech tvorby přívalových odtoků. Metody včasné výstrahy vycházejí z nových poznatků o hydromechanických mechanismech tvorby odtoku z malých povodí. Jsou podrobně popsány jednotlivé rizikové faktory a metody jejich detekce.
Biogeochemické cykly ekologicky významných prvků v měnících se přírodních podmínkách lesních ekosystémů NP Šumava
Správa národního parku Bayerische Wald ; Česká zemědělská univerzita, Fakulta lesnická a environmentální ; Ústav pro hydrodynamiku AV ČR, Praha ; Hydrobiologický ústav AV ČR, České Budějovice ; Česká geologická služba, Praha ; Beudert, Burkhart ; Máca, Petr ; Šír, Miloslav ; Tesař, Miroslav ; Metelka, Václav ; Vrba, Jaroslav ; Kopáček, Jiří ; Oulehle, Filip ; Hofmeister, Jeňýk ; Hruška, Jakub
Zpráva shrnuje poznatky získané v období listopad 2004 - prosinec 2005, které jsou doplněny o předchozí pozorování členů autorského kolektivu. Zaměření je na biogeochemické a hydrologické charakteristiky území na obou stranách Šumavy. Zpráva je rozdělena do částí: Zhodnocení látkových toků v NP Šumava na třech povodích s různým typem managementu; Chemismus půd a jehličí ve studovaných povodích; Modelování dlouhodobého vývoje chemismu vod a půd; Změny chemismu a oživení Rachelsee na Šumavě v důsledku kůrovcové kalamity a zotavování ekosystému z acidifikace; Vyhodnocení vodního režimu půd na lokalitách lišících se vegetačním krytem v Národním parku Šumava; Vliv usazených srážek na vodní a látkovou bilanci malého horského povodí.
Evaluation of hydrological and climatic features of fast growing trees for energy use
Weger, J. ; Šír, Miloslav
Microclimatic changes in plantations of fast growing trees (FGT) against grassland consist in reducing the max. daily air temperatures of ground in sunny and warm days to 4 to 5º C, when is available soil water for transpiration. Minimum temperatures of ground air are significantly less affected; they are generally higher under canopy of FGT. Daily air humidity on hot days is usually greater in plantations of FGT than in grassland. In the growing season, soil temperatures are lower in plantations of FGT than in the stands under grass cover. Reduction of daily air temperatures and soil temperatures under canopy of FGT is mainly due to the cooling effect of transpiration. Shielding effect of high vegetation is not the dominant cause of temperature reduction. Large-scale plantations of FGT will have no observable effect on the temperature of the countryside or on the hydrological cycle. They will not cause land draying and reduction of runoff from the landscape.
Runoff from a small mountain basin due to soil water oversaturation
Vondrka, A. ; Šír, Miloslav ; Tesař, Miroslav
Analysis of runoff in a small mountain basin enables better understanding of the mechanisms of extreme runoff formation in small watersheds. Especially the proportion of old (soil) and new (rain) water in various stages of runoff is evaluated. The paper describes a method to determine when the new rainwater flows in a stream. The method is based on measurements of water conductivity and the concentration of K+ ions in the flowing water. The aim is to distinguish between old and new water flow in the closing profile of a small mountain basin. As new water is called water, which was in contact with the soil only a short time - several minutes or hours. The term old water refers to water that was retained in the soil for many days or weeks. In the growing season, the K+ concentration in soil water decreases with the duration of contact of water with soil and plant roots, thus the K+ concentration in the water is an indicator of its age,ie. of the length of the delay of water in the soil.

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2 Šír, M.
3 Šír, Michal
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