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Start Over Language Slovak Rights http://creativecommons.org/licenses/by-nc-sa/4.0/ Rights policy:public Harvested from CDK Harvested from CDK Date Unknown

1112. Vztahy mezi vodní hodnotou sněhu v zalesněném terénu a na otevřeném prostranství v experimentálních povodích Jizerských hor

Creator:
Stehlík, Jiří and Bubeníčková, Libuše
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
snow water equivalent, snow water storage, forest and open area, the Jizera Mts, vodní hodnota sněhu, sněhové zásoby, les a otevřené prostranství, and Jizerské hory
Language:
Slovak
Description:
The study deals with the analyses of long-term snow measurements performed in the top-parts of the Jizera Mts. The homogenity of the measured data and the relationship between the snow cover parameters and elevation are tested. The main task is to determine the amount of snow sotrage in forest based on the measurements in open areas. It was proved that: i) the relationships can be defined by means of simple linear regression, ii) the resulting equations differ during the winter season depending on snow accumulation and snow melting periods respectively. The results re the first step in the research which will continue with analyses from other sites in Jizera mountains and new established measurements in the selected climatological stations. and Článek se zabývá analýzou sněhoměrných měření prováděných dlouhodobě ve vrcholových partiích Jizerských hor. Testována je homogenita naměřených dat a závislost parametrů sněhové pokrývky na nadmořské výšce. Jádrem práce je však zjišťování vztahů pro výpočet sněhových zásob v lesním prostředí na základě měření z volných prostranství. Bylo prokázáno, že i)tyto převodní vztahy lze odvodit pomocí jednoduché lineární regrese, ii)výsledné rovnice se liší během zimního období - pro období akumulace sněhové pokrývky jsou jiné než pro období tání. Výsledky jsou prvním krokem výzkumu, který bude pokračovat analýzami dalších profilů v Jizerských horách a nově zaváděných měření na souboru vybraných klimatických stanic.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1113. Warming Vistula River - the effects of climate and local conditions on water temperature in one of the largest rivers in Europe

Creator:
Ptak, Mariusz, Sojka, Mariusz, Graf, Renata, Choiński, Adam, Zhu, Senlin, and Nowak, Bogumił
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
water temperature, transit rivers, trends, transformation factors, and Central Europe
Language:
Slovak
Description:
The paper evaluates changes in the water temperature of the Vistula River – one of the longest rivers in Europe. Mean monthly and annual water temperatures from the period 1971–2017 for 11 stations along the entire length of the river revealed the increasing trends. The mean increase in water temperature in the analysed multi-annual period was 0.31 °C dec–1. In the majority of analysed stations, the key factor determining changes in the water temperature of the river was air temperature. The observed water warming in the Vistula River should be considered an exceptionally unfavourable situation in the context of importance of water temperature for a number of processes and phenomena occurring in river ecosystems. Given the scale of changes, fast measures should be undertaken to slow down the warming.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1115. Water flow in a single fracture with variable aperture

Creator:
Veselý, Marek and Mls, Jiří
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
fracture flow, variable aperture, percolation probability, contact area, puklinové proudění, proměnlivé rozevření, perkolační pravděpodobnost, and kontaktní plocha
Language:
Slovak
Description:
Water flow in a single fracture with variable aperture was studied by means of numerical modeling. For this purpose, two numerical models were developed. Computer simulations of water flow rates, fracture contact areas and transmissivities for fractal and nonfractal fractures were performed. Water flow rates were approximated by a trend function. The effect of the grid size upon the stability of results as well as the dependence of the fracture transmissivity on rate of contact area were studied. The achieved results were compared with measured data. and Studie se věnuje proudění podzemní vody v samostatné puklině metodou numerického modelování. K tomu účelu jsme vyvinuli dva numerické modely. Byly provedeny série numerických simulací proudění vody a výpočtu kontaktní plochy a transmisivity pukliny pro obecný typ pukliny. Byly studovány vliv velikosti sítě generované pukliny na stabilitu perkolačních charakteristik a závislost propustnosti pukliny na poměrné velikosti kontaktní plochy. Získané výsledky byly vyhodnocovány ve vztahu ke známým experimentálním datům.
Rights:
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1116. Water repellency decreases with increasing carbonate content and pH for different biocrust types on sand dunes

Creator:
Drahorad, Sylvie Laureen, Felde, Vincent J. M. N. L., Ellerbrock, Ruth H., and Henss, Anja
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
organic matter composition, surface characteristics, TOF-SIMS, biocrust, carbonate content, and water repellency
Language:
Slovak
Description:
Biocrusts are biological communities that occupy the soil surface, accumulate organic matter and mineral particles and hence strongly affect the properties of the soils they cover. Moreover, by affecting water repellency, biocrusts may cause a preferential infiltration of rainwater, with a high impact on the formation of local water pathways, especially for sand dunes. The aim of this study is to shed light on the connections between water repellency and pH, carbonate and organic matter content in two dune ecosystems with different biocrust types. For this, we used contact angle measurements, gas volumetric carbonate determination and organic matter characterization via FT-IR and TOFSIMS. In both ecosystems, moss-dominated biocrusts showed higher water repellency and higher amounts of organic matter compared to algal or cyanobacterial biocrusts. Surprisingly, the biocrusts of the two dune systems did not show differences in organic matter composition or organic coatings of the mineral grains. Biocrusts on the more acidic dunes showed a significantly higher level of water repellency as compared to higher carbonate containing dunes. We conclude that the driving factor for the increase in water repellency between cyanobacterial and moss-dominated biocrusts within one study site is the content of organic matter. However, when comparing the different study sites, we found that higher amounts of carbonate reduced biocrust water repellency.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1117. Water stable aggregates of Japanese Andisol as affected by hydrophobicity and drying temperature

Creator:
Leelamanie, D.A.L. and Karube, Jutaro
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
aggregate stability, contact angle, floating time, Japanese Andisol, hydrophobicity, and wetting rate
Language:
Slovak
Description:
Hydrophobicity is a property of soils that reduces their affinity for water, which may help impeding the pressure build-up within aggregates, and reducing aggregate disruption. The purpose of this study was to examine the relation of soil hydrophobicity and drying temperature to water stability of aggregates while preventing the floating of dry aggregates using unhydrophobized and hydrophobized surface Andisol. Soil was hydrophobized using stearic acid into different hydrophobicities. Hydrophobicity was determined using sessile drop contact angle and water drop penetration time (WDPT). Water stability of aggregates (%WSA) was determined using artificially prepared model aggregates. The %WSA increased as the contact angle and WDPT increased. Contact angle and WDPT, which provided maximum %WSA showing less than 1 s of floating, was around 100° and 5 s, respectively. Although the %WSA gradually increased with increasing contact angle and WDPT above this level, high levels of hydrophobicity initiated aggregate floating, which would cause undesirable effects of water repellency. Heating at 50°C for 5 h d-1 significantly affected %WSA and hydrophobicity in hydrophobized samples, but did not in unhydrophobized samples. The results indicate that the contact angle and wetting rate (WDPT) are closely related with the water stability of aggregates. The results further confirm that high levels of hydrophobicities induce aggregate floating, and the drying temperature has differential effects on hydrophobicity and aggregate stability depending on the hydrophobic materials present in the soil.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1118. Water table effects on measured and simulated fluxes in weighing lysimeters for differently-textured soils

Creator:
Wegehenkel, Martin and Gerke, Horst H.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
weighable lysimeters, modelling, Hydrus-1D, drainage, and boundary condition
Language:
Slovak
Description:
Weighing lysimeters can be used for studying the soil water balance and to analyse evapotranspiration (ET). However, not clear was the impact of the bottom boundary condition on lysimeter results and soil water movement. The objective was to analyse bottom boundary effects on the soil water balance. This analysis was carried out for lysimeters filled with fine- and coarse-textured soil monoliths by comparing simulated and measured data for lysimeters with a higher and a lower water table. The eight weighable lysimeters had a 1 m2 grass-covered surface and a depth of 1.5 m. The lysimeters contained four intact monoliths extracted from a sandy soil and four from a soil with a silty-clay texture. For two lysimeters of each soil, constant water tables were imposed at 135 cm and 210 cm depths. Evapotranspiration, change in soil water storage, and groundwater recharge were simulated for a 3-year period (1996 to 1998) using the Hydrus-1D software. Input data consisted of measured weather data and crop model-based simulated evaporation and transpiration. Snow cover and heat transport were simulated based on measured soil temperatures. Soil hydraulic parameter sets were estimated (i) from soil core data and (ii) based on texture data using ROSETTA pedotransfer approach. Simulated and measured outflow rates from the sandy soil matched for both parameter sets. For the sand lysimeters with the higher water table, only fast peak flow events observed on May 4, 1996 were not simulated adequately mainly because of differences between simulated and measured soil water storage caused by ET-induced soil water storage depletion. For the silty-clay soil, the simulations using the soil hydraulic parameters from retention data (i) were matching the lysimeter data except for the observed peak flows on May, 4, 1996, which here probably resulted from preferential flow. The higher water table at the lysimeter bottom resulted in higher drainage in comparison with the lysimeters with the lower water table. This increase was smaller for the finer-textured soil as compared to the coarser soil.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1119. Water vapour adsorption on water repellent sandy soils

Creator:
Orfanus, Tomas, Amer, Abdel-Monem Mohamed, Jozefaciuk, Grzegorz, Fulajtar, Emil, and Čelková, Anežka
Type:
article, model:article, and TEXT
Subject:
soil sorptivity, hydrophobization, adsorption isotherm, fractal dimension, and specific surface area
Language:
Slovak
Description:
Soil sorptivity is considered a key parameter describing early stages of water (rain) infiltration into a relatively dry soil and it is related to build-up complexity of the capillary system and soil wettability (contact angles of soil pore walls). During the last decade an increasing water repellency of sandy soils under pine forest and grassland vegetation has been frequently observed at Mlaky II location in SW Slovakia. The dry seasons result in uneven wetting of soil and up to hundredfold decrease in soil sorptivity in these vegetated soil as compared to reference sandy material, which was out of the reach of ambient vegetation and therefore readily wettable. As far as water binding to low moisture soils is governed by adsorption processes, we hypothesized that soil water repellency detected by water drop penetration test and by index of water repellency should also influence the water vapour adsorption parameters (monolayer water content, Wm, specific surface area, A, maximum adsorption water, Wa, maximum hygroscopic water MH, fractal dimension, DS and adsorption energies, Ea) derived from BET model of adsorption isotherms. We found however, that the connection of these parameters to water repellency level is difficult to interpret; nevertheless the centres with higher adsorption energy prevailed evidently in wettable materials. The water repellent forest and grassland soils reached less than 80% of the adsorption energy measured on wettable reference material. To get more conclusive results, which would not be influenced by small but still present variability of field materials, commercially available homogeneous siliceous sand was artificially hydrophobized and studied in the same way, as were the field materials. This extremely water repellent material had two-times lower surface area, very low fractal dimension (close to 2) and substantially lower adsorption energy as compared to the same siliceous sand when not hydrophobized.
Rights:
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1120. Water’s path from moss to soil: a multi-methodological study on water absorption and evaporation of soil-moss combinations

Creator:
Thielen, Sonja M., Gall, Corinna, Ebner, Martin, Nebel, Martin, Scholten, Thomas, and Seitz, Steffen
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
biological soil crusts, bryophytes, ecohydrology, moss structure, moss hydrology, and rainfall interception
Language:
Slovak
Description:
Mosses are often overlooked; however, they are important for soil-atmosphere interfaces with regard to water exchange. This study investigated the influence of moss structural traits on maximum water storage capacities (WSCmax) and evaporation rates, and species-specific effects on water absorption and evaporation patterns in moss layers, mosssoil- interfaces and soil substrates using biocrust wetness probes. Five moss species typical for Central European temperate forests were selected: field-collected Brachythecium rutabulum, Eurhynchium striatum, Oxyrrhynchium hians and Plagiomnium undulatum; and laboratory-cultivated Amblystegium serpens and Oxyrrhynchium hians. WSCmax ranged from 14.10 g g–1 for Amblystegium serpens (Lab) to 7.31 g g–1 for Plagiomnium undulatum when immersed in water, and 11.04 g g–1 for Oxyrrhynchium hians (Lab) to 7.90 g g–1 for Oxyrrhynchium hians when sprayed, due to different morphologies depending on the growing location. Structural traits such as high leaf frequencies and small leaf areas increased WSCmax. In terms of evaporation, leaf frequency displayed a positive correlation with evaporation, while leaf area index showed a negative correlation. Moisture alterations during watering and desiccation were largely controlled by species/substrate-specific patterns. Generally, moss cover prevented desiccation of soil surfaces and was not a barrier to infiltration. To understand water’s path from moss to soil, this study made a first contribution.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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