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Design of early warning system against lightning floods in mountain conditions
Tesař, Miroslav ; Šír, Miloslav ; Polívka, Jiří
The sophisticated local warning system against flash floods in mountain conditions is described. It is designed using the latest knowledge on the hydrodynamic mechanisms of storm runoff. It was found that extreme discharges are caused by these factors and their combinations: (1) saturation of soil cover with water, (2) soil surface hydrophobia, (3) gravity destabilized flow of water in the soil, (4) extreme rainfall, usually after prolonged dry period. Typical combinations causing extreme runoff, are (1) and (3) - the water saturation of soil cover can cause gravity destabilized flow induced by a small rain, (2) and (4) - long-term drought may cause the hydrophobic surface of the soil and simultaneously trigger extreme rain.
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Use of stable hydrogen and oxygen isotopes in hydrology of small catchments in the Czech and Slovak Republic
Šanda, M. ; Vitvar, T. ; Holko, L. ; Blažková, Š. ; Bůzek, F. ; Císlerová, M. ; Fottová, D. ; Kostka, Z. ; Kulasová, A. ; Kvítek, T. ; Šnytr, O. ; Tachecí, P. ; Tesař, Miroslav ; Vícha, Z. ; Žlábek, P.
The contribution summarizes the development of isotope hydrology and hydrogeology in the Czech and Slovak Republic over the past 40 years. Records of 18O and 2H in nine experimental catchments and their interpretation provide a description of runoff component mixing from various soil and rock environments, as well as a calculation of mean water residence time of 7 to 25 months. The 18O and 2H content in two profiles of the Jizera River and two boreholes in the lower reaches shows little communication of river water with the groundwater supply resources in the Lower Jizera area; the communicaton increases with pumping intensity. The 18O and 2H content in wetlands and groundwater in two catchments of the Jizera Mts. shows the differences in recharge to the wetlands via groundwater or precipitation. The isotope hydrology and hydrogeology perspectives in the ČR and SR include capacity building, cooperation of laboratories and conjunctive use of izotopic and hydrogeochemical approaches.
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Influence of the development of vegetation cover in the basin on the regime of surface water and groundwater resources
Buchtele, Josef ; Tesař, Miroslav
Variability of water regime is influenced usually not only by the changes of vegetation cover in the annual cycle, but also by the vegetation development in the span even of several decades. The resulting evapotranspiration requirement depends on actual climatic conditions; moreover the needs of soil moisture and the oscillation of solar radiation are also significant. The simulations of rainfall–runoff process have been used with the intention to follow the role of the developing vegetation cover and long-term climatic fluctuations. The differences between monitored and simulated runoff in the relatively long periods are the possible tool for the appraisal of changes in the water regime, which are influenced also by the changes of evapotranspiration need.
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Hydrology of a small basin 2011
Šír, Miloslav ; Tesař, Miroslav
The book includes the full text of 73 scientific articles. These articles were prepared as the contributions for the Conference with international participation “Hydrology of a small basin 2011” that was held from March 8th to March 10th 2011 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 and Czech Committee for Hydrology. The book was published by the Institute of Hydrodynamics ASCR in Prague in 2011.
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Hydrology of small basin 2008
Šír, Miloslav ; Tesař, Miroslav ; Lichner, Ľ.
The book includes the full text of 48 scientific articles. These articles were prepared as the contributions for the Conference with international participation “Hydrology of a small basin 2011” that was held from April 23th to April 24th 2008 in Prague. The Conference was organized by the Institute of Hydrodynamics ASCR, v.v.i. in Prague; Institute of Hydrology SAS in Bratislava; the Czech Water Management Society in Prague and Czech Committee for Hydrology. The book was published by the Institute of Hydrodynamics ASCR, v.v.i. in Prague in 2008.
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Hydrograph separation using ionic concentration measurement
Vondrka, A. ; Šír, Miloslav ; Tesař, Miroslav
In this article a method of hydrograph separation based on ionic concentration measurement is discussed. The goal of the method described is to distinguish the “old” and “new” water flowing in a stream in the closing profile of a small mountainous catchment. The “new water” is the rain water or the soil water which contact with the soil has a very short duration, a few minutes or hours. The term “old water” denotes water which was stored in the soil cover for many days or weeks. The Na+ and K+ ions will be used as the tracers distinguishing the “old” and “new” water. Namely, it is known that the concentration of the K+ ion in the soil water is decreasing according the growing duration of the contact of water with soil and plants roots. Ionic concentration will be measured with the help of ion selective electrodes. Two and three component separation algorithm will be used for the hydrograph separation.
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Formation of extreme rains in the Krkonoše Mts. in summer 2002 and 2006
Tesař, Miroslav ; Šír, Miloslav ; Fišák, Jaroslav
In the article, hydrological and meteorological conditions preceding two extreme rains in the Krkonoše Mts. in summer 2002 and 2006 are discussed. Both were caused by cyclones, which moved from Hungary to Poland. Meteorological conditions preceding the rains were very similar in both cases – long-lasting lack of precipitation and extraordinary high air temperatures. We analyze the role of insufficient plant transpiration in the rise of both extreme rains.
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Hydrologic extremes and gross primary productivity in the Liz catchment
Šír, Miloslav ; Tesař, Miroslav ; Lichner, Ľ. ; Váchala, J. ; Krejča, M.
The synergy between hydrologic extremes, plant transpiration, gross primary productivity, and soil water retention was studied in the experimental area Zábrod – meadow in the Bohemian Forest. Heat balance, potential and actual transpiration, entropy production and gross primary productivity were evaluated. It was found that the soil water retention is the crucial factor determining hydrologic pattern and gross primary productivity. Insufficient soil water retention leads to small entropy production by evaporation and small gross primary productivity, which results in the extremalization of the hydrologic cycle. On the other hand, in the case of sufficient soil water retention, high entropy production by transpiration and high gross primary productivity leads to the stability of the hydrologic cycle.
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Dynamika půdní vody na Šumavě a v Krkonoších v srpnu 2002
Tesař, Miroslav ; Krejča, M. ; Polívka, Jiří ; Šír, Miloslav
The soil water movement during extreme rain is analysed in the Doupě and Kout catchment (Šumava Mts, Southern Bohemia) and in the Modrý Důl catchment (Krkonoše Mts., Northern Bohemia). Two cyclones, which moved from Hungary to Poland, caused extreme rainfall and subsequent extreme runoff in August, 2002. Precipitation, air and soil temperature, and tensiometric pressure were recorded in catchments. The analysis showed that the huge rain amount in August 2002 exceeded the retention capacity of the catchment covered by mature spruce forest and dwarf pine forest (Modrý Důl), dead forest and herb undergrowth (Kout), clearing covered by herbs (Doupě). It means that the plant cover played a negligible role in the runoff generation. The soil cover was not able to prevent the country from catastrophic runoff because its retention capacity is rather low (60 – 90 mm).
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