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Klimatická změna a transpirace rostlin
Šír, Miloslav ; Tesař, Miroslav ; Lichner, Ľ. ; Syrovátka, O.
The article shows how the plant transpiration cools the boundary level of the atmosphere. In a summer day, when the heat input is 5 to 6 kWh/m2 per day, in the mountainous and submontane areas of the Czech Republic (600 to 1400 m a.s.l.) the plant transpiration decreases: (1) maximum temperature of plant cover from 47 to 25 degrees C, (2) maximum temperature of boundary level of the atmos-phere from 29 to 21 degrees C, (3) maximum temperature of the soil in the depth of 15 cm from 15 to 8 degrees C. The cooling caused by plant transpiration substantially af-fects the energy balance of the land surface. Insufficient transpiration caused an increment of thermal energy of about 23
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Modeling water regime in a small watershed
Vogel, T. ; Tesař, Miroslav ; Císlerová, M.
The paper is focused on the role of the soil water regime in formation of subsurface runoff. One-dimensional dual-permeability model is used to simulate variably saturated movement of water in the soil, in which preferential flow effects were reported. Simulated pressure head variations are compared with the available tensiometric observations. A possible conceptual model of prevailing water transfer mechanism in a hillslope segment is presented. The shallow subsurface flow is approximated by one-dimensional saturated flow along the inclined soil-bedrock interface. For a selected growing season, the model generated hillslope hydrograph is compared with the observed stream hydrograph. The simulated subsurface runoff peaks compare well with the measured stream discharge peaks.
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Rainfall - runoff relationship in small mountainous catchments
Tesař, Miroslav ; Šír, Miloslav ; Pražák, J.
The singular phenomenon of flow instabilities was observed in a small catchment: in some situations, the water supplied by rain caused a pronounced decrease in the soil water content. This soil water movement can be explained by assuming an irregularly oscillating outflow of soil water into lower horizons. In these situations a large volume of water flows through the soil; on the hydrological scale, this phenomenon forms a great part of the outflow from a watershed. The phenomenon can be described in the frame of the instability driven flow theory and explained as consequence of the porous soil bodyŽs capacity to become conductive in results of a very little change of its moisture. In this way, the soil profile can attenuate or amplify the rainfall pulses during their transformation to the outflow.
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Hydrologie půdy v malém povodí
Šír, Miloslav ; Lichner, Ľ. ; Tesař, Miroslav
Kniha obsahuje 35 článků, které byly připraveny jako příspěvky pro konferenci s mezinárodní účastí Hydrologie půdy v malém povodí, která se konala dne 15.10. 2003 v Praze. Práce, obsažené v tomto sborníku, se věnují hydrologii půdy v malém povodí v mnoha souvislostech s návaznými vědeckými a inženýrskými disciplínami. Příspěvky jsou rozděleny do osmi oddílů.
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