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The insoluble particles in water deposited from fog at Milešovka Observatory (Czech Republic)
Bartůňková, Kristýna ; Fišák, Jaroslav ; Stoyanova, V. ; Schoumkova, A.
This study concerns insoluble chemical pollution of fog at Milešovka Observatory in the Czech Republic. In period from August 2006 till July 2007, 25 fog samples at the top of Milešovka Mountain in České Středohoří Mountains were collected by active fog water collector. Water samples were filtered. From 53 to 116 particles from every sample were chosen according to the quantity of particles found in dried filters. Altogether it was more than 2000 particles. Particles were examined with the help of Scanning Electron Microscope and Energy Dispersive X-Ray Spectrometer to distinguish sizes, shapes and composition. After analyzing the data, statistical evaluation was made. Particles were put into categories according to their shapes on spherical and not spherical. Typical particles like Al, Si, K, Fe or Ca-rich particles were determined. Focus was also to particles with rarely represented elements like Ni, Au, Pb, Cu, Zr and Ba. Groups of typical insoluble particles were collated according to meteorological conditions - synoptic situations and wind directions which prevailed in the days of fog events in order to try to find out possible sources of this fog pollution.
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Using the dye tracer for visualization of preferential flow in macro- and micro-scale
Kodešová, R. ; Němeček, K. ; Kodeš, V. ; Žigová, Anna
Study is focused on the visualization of the preferential flow in different soil types and their horizons using the dye tracer experiment. The field ponding dye infiltration experiments were performed in two soil types: Haplic Luvisol and Haplic Cambisol. In addition, the thin soil section were made and micromoprphological images were used to study soil aggregate structure and dye distribution in microscale. Images of the dye patterns (taken in macro- and micro-scales) documented very different nature of the preferential flow in different soil types and also within the soil profiles.
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Evapotranspiration of selected agricultural and forest species
Kučera, J. ; Urban, J. ; Trnka, Miroslav ; Fischer, Milan ; Krofta, K. ; Duffková, R.
The aim of this article is a comparison of evapotranspiration (ET) of different covers (turf grass, clover (Trifolium pratense), winter wheat (Triticum aestivum), hops (Humulus lupulus) and the high density poplar stand (J-105, Populus nigra x Populus Maximowiczii)) with the potential evapotranspiration (PET) and the general description the ET rates dynamic during the season. The second goal is to quantify the ratio of the transpiration and the whole evapotranspiration for the two contrasting cultures – the hops and poplars stand. The daily maximal sum of the grass ET reached, similarly like for the other species, up to 5–6 mm per day, which comprises 85–93 % of PET. Significantly higher ET was showed by the culture of clover. On the other hand, the lowest values were performed by the poplar stand in the first year after coppicing. The transpiration to evapotranspiration ratio resulted in 40–70 % by the hops and 80–90 % in case of the poplars.
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Water balance in short rotation poplar coppice and reference grass-plot in conditions of Czech-Moravian Highlands
Orság, Matěj ; Fischer, Milan ; Trnka, Miroslav ; Hlavinka, Petr ; Kučera, J. ; Balek, J. ; Žalud, Zdeněk
This text presents results of a study focusing on differences of water balance between two contrasting cultures - short rotation poplar coppice and grass plot in conditions of Czech-Moravian Highlands. Actual evapotranspiration (by Bowen ratio energy balance method), precipitation and soil moisture in two layers (0 – 0.45 m and 0.45 – 0.90 m) were measured on both plots during seasons 2008 – 2010. The seasonal water lost through evapotranspiration was higher for the grass (560.4 and 508 mm for grass and 523.8 and 351.8 mm for poplar during growing season 2009 and 2010 respectively), but generally the observed amounts of ETa are comparable for both cultures and within the range of values described in literature. Results of soil moisture measurements expressed as soil water availability [mm] were compared with simulations obtained from water balance model SoilClim. The model a little bit underestimated the amount of available water in the system, since based on water balance closure we suggest that there is a higher water income than was recorded from precipitation. This extra water found in observed systems may be supplied probably by lateral underground water inflow from the upper fields.
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The impact of rain precipitation on dust concentration in the atmosphere
Fišák, Jaroslav ; Bartůňková, Kristýna
In this contribution the impact of precipitation on the amount of dust in the air is studied. Two precipitation characteristics are used: precipitation amount and time of precipitation duration. For the determination of dust concentrations dry filtering method was used. By this method the air is being sucked in by the suction pump over the head with filter. The exposition of the filter lasted approximately one weak. The time of samples collecting was not absolutely constant. Therefore it was necessary to choose relative characteristics. Precipitation amount for daily exposition of the filter was used. Even more difficult was to characterize the time of precipitation duration. In this case percent expression of precipitation duration to the time of filter exposition was used.
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Relationship between chemistry of surface water and geological environment in the forest catchment LIZ in the Šumava Mts
Škoda, S. ; Váchal, J. ; Dumbrovský, M. ; Tesař, Miroslav ; Váchalová, R.
More then 20 years the chemistry of surface water has been observed within GEOMON project in the Zdíkov region in the Šumava Mts. The knowledge of composition and chemistry of geological environment is very important for assessment of input and output of matter to/from this catchment. The geological underground has been make up of migmatitize biotitic and sillimanit-biotitic paragneises of Šumava Moldanubicum. Soils, represented by oligotrophic and oligomezotrophic cambisoils, are very acid, sorption unsaturated. Their silicate buffering system significantly contributes to decrease leaching of calcium, manganese, chlorine and total aluminum, and so to reduction of intensity weathering of rocks.
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Simulation of water and heat transport considering preferential flow. Experimental site Na Lizu
Votrubová, J. ; Dohnal, M. ; Vogel, T. ; Tesař, Miroslav
Coupled water and heat transport in soil profile at the experimental site Na Lizu (Volynka headwater catchment, Sumava Mountains, southern Bohemia) is studied. The site is located on a mild slope cov-ered with grass. The soil is Cambisol developed upon biotite paragneiss bedrock. One-dimensional dual-continuum model with semi-separate flow domains representing the soil matrix and the network of preferential pathways (S1D) is employed. Hydraulic parameters of the model are set based on labo-ratory retention curve measurements and in-situ measurements of hydraulic conductivity. Thermal pa-rameters are estimated using methodology of Cote and Konrad (2005). Simulation is conducted for the summer season of 2009. The in-situ monitored precipitation and soil surface temperatures are used as the model upper boundary condition. Model performance was evaluated through comparison with soil water pressure and soil temperatures monitored in situ.
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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.
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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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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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