Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 3 - 14, doi:
Scientific Paper, Slovak

Miroslava Jarabicová, Mária Pásztorová, Peter Minarič, Jana Skalová: Impact of the climate change on evapotranspiration in the Poiplie area

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• This paper is aimed to assess the impact of climate change on water regime of wetland in the area of Poiplie Ramsar site. To simulate the climate change CGCM3.1 global model (SRES A2 pessimistic scenario and SRES B1 optimistic scenario) and KNMI and MPI regional models were selected as the most appropriate. For the reference period 20-year period of year 1977-1996 was chosen, which is within the evaluation compared with the 20-year time horizons 2020, 2050 and 2080. Simulation of soil water regime was carried out using a GLOBAL model. Within the soil water regime evaluation actual evapotranspiration was evaluated in this paper. Actual evapotranspiration has in the future in the studied area also increasing course over the reference period, while the SRES A2 pessimistic scenario expected the increase of 24%, KNMI regional model the increase of 21% and SRES B1 optimistic scenario and MPI regional model the increase of 19%. The development of actual evapotranspiration is derived from the predicted increase in air temperature and precipitation. On the base of these results the ongoing climate change do not cause a dramatic changes in Poiplie Ramsar site, thereby this unique wetland ecosystem should be preserved in the future.
  
  KEY WORDS: actual evapotranspiration, climate scenario, wetland, soil water regime, mathematical modeling
  
  Address:
  - Miroslava Jarabicová, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.:+421 02 592 74 626 Fax.: Email: miroslava.jarabicova@stuba.sk)
  - Mária Pásztorová, Výskumný ústav vodného hospodárstva, Nábrežie arm. gen. L. Svobodu 5, 812 49 Bratislava 1, Slovenská republika
  - Peter Minarič, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Jana Skalová, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 15 - 23, doi:
Scientific Paper, Slovak

Július Šútor, Justína Vitková, Štefan Rehák, Peter Stradiot: Impact of evapotranspiration deficit on soil water dynamics under condition of Zahorská Lowland

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• Evapotranspiration deficit (ED) quantifies the relation between demand of water which is necessary for development of vegetation cover from the potential (Eto) and actual (Eta) evapotranspiration i.e. (Eto - Eta). Optimal status of supplementing the vegetation cover occurs when Eto = Eta, i.e. the relative evapotranspiration Eta/Eto = 1. Climatologists quantify the impact of the climate change on vegetation with help of ED. Climate scenarios determined the climate change impact for environment in Slovakia for time horizons 2010, 2030 a 2075 just by ED values. However, there is missing quantification of climate change impact on the water supply in the aeration zone. In order to fill this gap it is necessary to determine the relation between the ED values and the water supply in soil. Such quantification requires in a given locality (resp. area) to process parameters Eto, Eta and Eta/Eto, precipitation totals P, hydrophysical parameters of soil (HFCHP) and data from soil moisture monitoring. The result of quantification is the allotment of values of water supply in soil to values of evapotranspiration deficit. This paper presents the results of graphically processed relation between ED and water supply in soil in the locality Malé Leváre in Záhorská Lowland. The quantification used above mentioned parameters corresponding to this locality.
  
  KEY WORDS: evapotranspiration deficit, water supply in soil, soil moisture monitoring, moisture regime in soil
  
  Address:
  - Július Šútor, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika (Corresponding author. Tel.:+421-2-49268-302 Fax.: Email: sutor@uh.savba.sk)
  - Justína Vitková, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika
  - Štefan Rehák, Výskumný ústav vodného hospodárstva, Nábrežie arm. Gen. L. Svobodu 5, 812 49 Bratislava, Slovenská republika
  - Peter Stradiot, Výskumný ústav vodného hospodárstva, Nábrežie arm. Gen. L. Svobodu 5, 812 49 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 24 - 34, doi:
Scientific Paper, Slovak

Hana Hlaváčiková, Viliam Novák, Tomáš Orfánus, Michal Danko, Jozef Hlavčo: Stony soils hydrophysical characteristics. I. Hydraulic conductivities

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• Hydraulic conductivities and soil water retention curves are important properties of soils. They are needed to determine soil water content course in the soil profile. These characteristics are needed also as input parameters of mathematical soil water transport models. In case of the stony soils, problems arise with measuring and interpretation of measured values affected by presence of the stones mainly, in forested (mountainous), but also in some agricultural soils. This contribution presents measured hydraulic conductivities of stony soils and their interpretation, according to the measurement methods and stony soil structure characteristics. Relationship between hydraulic conductivity measured under field conditions and stoniness was not identified. Results from artificially prepared disturbed samples we used in laboratory, show a distinct relationship: saturated hydraulic conductivity decrease with stoniness increase.
  
  KEY WORDS: stoniness, hydraulic conductivity, soil characteristics measurement, mountainous soils
  
  Address:
  - Hana Hlaváčiková, Ústav hydrológie SAV Račianska 75 831 02 Bratislava, Slovenská republika (Corresponding author. Tel.:+4212 49268326 Fax.: Email: hlavacikova@uh.savba.sk)
  - Viliam Novák, Ústav hydrológie SAV Račianska 75 831 02 Bratislava, Slovenská republika
  - Tomáš Orfánus, Ústav hydrológie SAV Račianska 75 831 02 Bratislava, Slovenská republika
  - Michal Danko, Ústav hydrológie SAV Experimentálna hydrologická základňa Ondrašovecká 16 031 05 Liptovský Mikuláš, Slovenská republika
  - Jozef Hlavčo, Ústav hydrológie SAV Experimentálna hydrologická základňa Ondrašovecká 16 031 05 Liptovský Mikuláš, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 35 - 42, doi:
Scientific Paper, Slovak

Hana Hlaváčiková, Viliam Novák: Stony soils hydrophysical characteristics. II. Calculation methods of saturated hydraulic conductivity

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• This paper presents a review of saturated stony soil hydraulic conductivity calculation methods from scientific literature and results of measurements by different authors. Field and laboratory measurements point out to seemingly opposite results. Two different aspects of rock fragments influence upon the saturated hydraulic conductivity of stony soils are manifested here. Rock fragments decrease saturated hydraulic conductivity by decreasing the effective cross-section and by higher curvature of the soil water paths. Under natural conditions, additional pores can emerge at rock fragments and fine soil fraction interface. Interconnection of these pores can contribute to porosity increase, and consecutively to the hydraulic conductivity increase. Conditions of calculation methods application and discussion of different results are presented too.
  
  KEY WORDS: stoniness, saturated hydraulic conductivity, lacunar pores, effective cross-section area
  
  Address:
  - Hana Hlaváčiková, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika (Corresponding author. Tel.:+4212 49268326 Fax.: Email: hlavacikova@uh.savba.sk)
  - Viliam Novák, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 43 - 50, doi:
Scientific Paper, Slovak

Hana Hlaváčiková, Viliam Novák: Stony soils hydrophysical characteristics. III. Soil water retention

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• The paper deals with influence of the rock fragments on stony soil water retention. Soil water retention curves were measured on artificially created mixtures of stony soils with zero rock fragments retention (sand and laboratory glass spherules) and on mixtures of stony soils with small rock fragments retention (sand and small rock fragments). Results of measurements were compared with calculated soil water retention curves. Measured soil water retention curves show a distinct decrease of retention capacity with stoniness increase. Measured soil water retention curves on samples with zero retention of rock fragments correspond well with the calculated ones, for stoniness 0.1−0.3. Measured soil water contents for pressure heads from -10 to -2 cm for stoniness 0.3−0.4 are higher in both data sets than calculated. The reason should be in existing voids at fragments−fragments contact, created by process of preparing samples.
  
  KEY WORDS: stoniness, soil water retention curves, rock fragments retention, macropores
  
  Address:
  - Hana Hlaváčiková, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika (Corresponding author. Tel.:+4212 49268326 Fax.: Email: hlavacikova@uh.savba.sk)
  - Viliam Novák, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 51 - 58, doi:
Scientific Paper, Slovak

Viera Kováčová: Adsorption parameters of nitrogen ions in the soil profile

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• The movement of solutes in a natural soil involves many complicated phenomena. Although significant understanding of the movement of chemicals in soils has been achieved, a number of theoretical and practical problems remain. Some experimental procedures were proposed to point out the principal physico-chemical phenomenon which is responsible for the shape of the adsorption isotherm deduced from batch or column experiments. Adsorption reactions may be divided into two general types: nonspecific and specific. Non-specific adsorption is independent of the individual characteristics of the ion except for its ionic charge. In the neighborhood of a charged surface, the counter ions are distributed in a diffuse layer near the surface where they balance the surface charge. Specific adsorption is a general term that includes all adsorption mechanisms other than simple coulombic attraction. In specific adsorption the individual characteristics of the ions and the surface determine the strength and the extent of adsorption. The adsorption experiments were perform to obtain the information about the interaction between the solute and the soil for three types of soils – calcaro-haplic phaeozem, calcaric fluvisol and fluvi-calcaric phaeozem. The transformations of nitrogen in soils and its intake in NH4 + and NO3 - form is markedly affected by physico-chemical properties of soils and these ions. Adsorption parameters kL from adsorption isoterms Si = f(ci) were estimated for these soils.
  
  KEY WORDS: adsorption parameters, soil, nitrogen ions, nitrogen pollution
  
  Address:
  - Viera Kováčová, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: kovacova@uh.savba.sk)

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 59 - 67, doi:
Scientific Paper, Slovak

Jana Urminská: Temporal changes the arsenic concentration in sediments and waters of selected water reservoirs of Piargs group

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• Water-courses and reservoirs are important as environment and water-economy too. The regions affected by mining activity are considered as risky regions, where an increased content of toxic substances-elements could be found. The aim of this paper was to analyse and evaluate the sediment and water of selected water reservoirs the Piargs group - the Počúvadlo, the Little Richňava, the Great Richňava, the Windšachta, to determine the concentrations of arsenic in monitored water reservoirs in the Banská Štiavnica region. In the study area samples were collected from year 2001 to 2010. Furthermore, our target is to determine the correlation relationships and the statistical significance of dependencies of analysed environmental parameters. For statistical processing the „Correlation coefficient by Spearman method“ and „analysis of the Index method“ was used. The analyses of the sediment samples were performed with the methods of flow electrochemistry and the atomic absorption spectrometry.
  
  KEY WORDS: arsenic, sediment, water, the correlation, water reservoirs
  
  Address:
  - Jana Urminská, Katedra environmentalistiky a zoológie, Fakulta agrobiológie a potravinových zdrojov, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, Slovenská republika (Corresponding author. Tel.:+421 037 641 4423 Fax.: Email: Jana.Urminska@uniag.sk)

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 68 - 77, doi:
Scientific Paper, Slovak

Danka Grambličková, Peter Turček, Monika Súľovská, Roman Ravinger: Verification of stability of left-side dike of dam Veľké Kozmálovce

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• The aim of the paper is verification of filtration stability of the body and subsoil of left-site dike of the hydraulic structures Veľké Kozmálovce at rapid drawdown of water in reservoir. At rapid decreasing of water level are flushing sediments and in this way it is possible to prevent they sedimentation. Actual allowable velocity of water level decreasing per day is not enough for effective flushing of sediments. Increasing the velocity of water level decreasing per day may improving effectiveness of reservoir cleaning and optimised the water management. Verification of the influence of water velocity of discharging water from reservoir on filtration stability of dike´s body is necessary for adaptation of manipulation regulations. The objective was solved using finite elements method as transient flow in vertical plane by program GeoStudio 2007.
  
  KEY WORDS: dike safety, subsoil, rapid drawdown of water, transient flow, filtration velocity, filtration stability, finite element method
  
  Address:
  - Danka Grambličková, Katedra geotechniky, SvF STU, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.:00421 2 592 74 670 Fax.: Email: danka.gramblickova@stuba.sk)
  - Peter Turček, Katedra geotechniky, SvF STU, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Monika Súľovská, Katedra geotechniky, SvF STU, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Roman Ravinger, Katedra geotechniky, SvF STU, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 78 - 86, doi:
Scientific Paper, Slovak

Renáta Dulovičová, Yvetta Velísková, Darina Takáčová: Assessment of silting up and trend of water quality in Chotárny channel

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• The article presents the current situation of silting up in one of the three main channels of the Žitný ostrov channel network – in the Chotárny channel. The rate of cross-section profiles aggradation along this channel was evaluated from the field measurements in 2012 which were extended for monitoring of water temperature and conductivity along the channel during measured period. Simultaneously the course of quality in this channel was statistically evaluated from accessible data of Slovak Hydrometeorological Institute database (SHI). There were evaluated the indicators of water quality which were monitored in single monitored profile at Chotárny channel in rkm 10,0 - Jánošíkovo na Ostrove during period 1991 – 2006 ( with focus to the same season as the field measurements in 2012 were performed). Unfortunately, longer range of data was not available. There was evaluated the trend of water temperature, pH values, conductivity and concentration of suspended solids and total dissolved solids( TDS).
  
  KEY WORDS: silting up, channel network, cross-section profile, longitudinal profile, pH, water temperature and conductivity, concentration of suspended and total dissolved solids
  
  Address:
  - Renáta Dulovičová, Ústav hydrológie SAV, Račianska 75, 838 11 Bratislava, Slovenská republika (Corresponding author. Tel.:+42102 49268280 Fax.: Email: dulovicova@uh.savba.sk)
  - Yvetta Velísková, Ústav hydrológie SAV, Račianska 75, 838 11 Bratislava, Slovenská republika
  - Darina Takáčová, Slovenský hydrometeorologický ústav, Jeséniova 17, 833 15 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 87 - 93, doi:
Scientific Paper, Slovak

Marek Sokáč, Danka Barloková, Ján Ilavský: Utilisation of green roofs technology as regulation and reduction runoff at urban catchment

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• Paper deals with urban catchment hydrology, as well as with changes in the urban catchment runoff in comparison with natural catchment. The aim of measures and constructions work of urban catchments is to come close to the hydrological characteristics of natural urban catchments. To achieve this, various methods of regulation and runoff reduction are used in urbanized catchments. Paper describes in more detail the utilisation of green roofs technology, which can be used for decentralized control and reduction of stormwater runoff in urban catchments. Further the possibilities of green roofs use, their advantages and disadvantages are described, in particular, their hydrological function, which significantly affects the hydrological characteristics of urban catchments, as well as the urban environment. At the end of the paper preliminary results of the project, focused on runoff reduction and regulation using green roofs are briefly described. Project is particularly focused also on green roofs effluent quality and the possibilities of use the runoff from green roofs as a source of service water as well.
  
  KEY WORDS: urban hydrology, runoff regulation, runoff reduction, green roofs
  
  Address:
  - Marek Sokáč, Katedra zdravotného a environmentálneho inžinierstva Stavebná fakulta Slovenská Technická Univerzita v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: marek.sokac@stuba.sk)
  - Danka Barloková, Katedra zdravotného a environmentálneho inžinierstva Stavebná fakulta Slovenská Technická Univerzita v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Ján Ilavský, Katedra zdravotného a environmentálneho inžinierstva Stavebná fakulta Slovenská Technická Univerzita v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 94 - 101, doi:
Scientific Paper, Slovak

Marek Sokáč, Yvetta Velísková: Determination of longitudinal and transverse dispersion coefficient in river: case study

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• Content of this paper is a presentation of measurements, carried out on the modified reach of the Hron River within the boundaries of the Brezno town. Field measurements were carried out at 1109 m long reach of the Hron River. This reach can be defined as a adjusted channel. Discharge during measurements ranges from 4,2 up to 5,3 m3s-1, with an average width in water level of 18,3 m, average depth of 0,41 m. The aim of the measurements was to determine the longitudinal and transverse dispersion coefficient, using continuous tracer injection. This paper describes the methodology of measurements and their evaluations. Longitudinal dispersion coefficient values ranged from 1,05 – 1,44 m2.s-1, transverse dispersion coefficients were in the range of 0,007 to 0,017 m2.s-1.
  
  KEY WORDS: pollution spreading, longitudinal dispersion coefficient, transverse dispersion coefficient, tracer experiments in real conditions, dimensionless dispersion coefficient
  
  Address:
  - Marek Sokáč, Katedra zdravotného a environmentálneho inžinierstva Stavebná fakulta Slovenská Technická Univerzita v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: marek.sokac@stuba.sk)
  - Yvetta Velísková, Ústav hydrológie SAV, Račianska 75, 831 02 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 102 - 109, doi:
Scientific Paper, Slovak

Ladislav Holko, Jozef Hlavčo, Zdeno Kostka: Spatial distribution of precipitation in a mountain catchment

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• The article evaluates spatial distribution of precipitation measured in mountain catchment of the Jalovecký creek (area 22.2 km2, mean altitude 1500 m a.s.l.) in the warm period of the year 2013. 13 recording rain gauges installed in the catchment at altitudes 820-1900 m a.s.l. measured from 16th May until 2nd October. The data showed that when it was raining, the rainfall occurred in all parts of the catchment. Study period, especially July and August was drier than the long-term average. Yet, maximum daily precipitation exceeded 60 mm and maximum 10-minute and hourly rainfalls in the mountain and foothill parts of the catchment were not very different. Monthly altitude gradient of rainfall was more pronounced only in the drier months. The location of a gauge (e.g. wind- or leeward position) was superior to the influence of altitude in the wetter month. About one quarter of daily precipitation exhibited good relationship with the altitude, i.e. correlation coefficient between altitude and rainfall amount was at least 0,6. In such cases the altitude gradient generally increased with increasing rainfall amount. Runoff response to similar rainfall events was different.
  
  KEY WORDS: spatial distribution of precipitation, mountain catchment, altitude gradient of precipitation
  
  Address:
  - Ladislav Holko, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovská 16, 03105 Liptovský Mikuláš, Slovenská republika (Corresponding author. Tel.:+421445522522 Fax.: Email: holko@uh.savba.sk)
  - Jozef Hlavčo, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovská 16, 03105 Liptovský Mikuláš, Slovenská republika
  - Zdeno Kostka, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovská 16, 03105 Liptovský Mikuláš, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 110 - 115, doi:
Scientific Paper, Slovak

Pavel Krajčí, Ladislav Holko, Juraj Parajka: Snow line in the upper Váh river basin in winters 2001-2013

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• Satellite images MODIS were used to determine the elevation of the snow line in the upper Váh river basin. Snow line reaches the lowest altitudes in January and February. The difference between snow line altitude among the snow rich and poor winters may achieve even 1000. In the period of rapid increase of discharges in the river network during the snowmelt season is the snow line steadily at an altitude of almost 1500 m. a.s.l.. It means that snow covers only about 14% of the area.
  
  KEY WORDS: snow line, MODIS, mountain catchment
  
  Address:
  - Pavel Krajčí, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovská 16, 03105 Liptovský Mikuláš, Slovenská republika (Corresponding author. Tel.:+421445522522 Fax.: Email: krajci@uh.savba.sk)
  - Ladislav Holko, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovská 16, 03105 Liptovský Mikuláš, Slovenská republika
  - Juraj Parajka, Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Karlsplatz 13/222, A-1040 Vienna, Austria

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 116 - 129, doi:
Scientific Paper, Slovak

Michal Danko, Pavel Krajčí, Jozef Hlavčo: The relationship between snow depth and snow water equivalent in the forest and in the open area in the Jalovecký creek catchment

 Full Text in PDF     61 DOWNLOADS

• In this paper, snow depth and snow water equivalent data from measurements in Jalovecky creek catchment in West Tatras were analyzed. The routine measurements of snow water equivalent run in the open areas and in the forested areas since 1987 down to the present. The main point of this work was to evaluate data over 26 years and to create maps of spatial distribution of snow cover (snow water equivalent, snow depth and snow density) dependent on altitude for 3 different parts of catchment. Maps of spatial distribution of snow cover were created by linear regression with altitude separately for open areas under 1700 m a.s.l., and for forested area. During the evaluation, we figured out, that there is another specific area located above 1700 m a.s.l. (crests and peaks of the mountains). In this area values of parameters of snow cover decline exponentially with rising altitude. The result is comparison and determination of actual parameters of snow cover for whole catchment from measurements in situ in profile Červenec (C1500) according to the maps of spatial distribution. In forested part of catchment canopy capture 32,81 % of snow precipitation. The average density of snow throughout the catchment is 332 kg m-3.
  
  KEY WORDS: Snow water equivalent, spatial distribution maps, correlation, influence of vegetation
  
  Address:
  - Michal Danko, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovecká 16, 031 05 Liptovský Mikuláš, Slovenská republika (Corresponding author. Tel.:+42144 5522522 Fax.: +42144 5522522 Email: danko@uh.savba.sk)
  - Pavel Krajčí, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovecká 16, 031 05 Liptovský Mikuláš, Slovenská republika
  - Jozef Hlavčo, Ústav hydrológie SAV, Experimentálna hydrologická základňa, Ondrašovecká 16, 031 05 Liptovský Mikuláš, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 130 - 142, doi:
Scientific Paper, Czech

Jana Pařílková, Michael Novák: Monitoring of snow cover using EIS method for determining the possibility of snow water equivalent

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• To identify the layers of snow, their's characteristics associated with a variable load of temperature, humidity, and own weight, has been elected indirect electrical method of measuring electrical impedance spectroscopy. Non-traditional measuring method was used in the locality “Orlické hory”, Czech Republic. The first obtained results are given in the paper.
  
  KEY WORDS: electrical impedance spectrometry, snow water equivalent, snow cover
  
  Address:
  - Jana Pařílková, Vysoké učení technické v Brně, Fakulta stavební, Ústav vodních staveb, Laboratoř vodohospodářského výzkumu, Veveří 95, 602 00 Brno, Česká republika (Corresponding author. Tel.:+420 54114 7284 Fax.: +420 54114 7288 Email: parilkova.j@fce.vutbr.cz)
  - Michael Novák, Vysoké učení technické v Brně, Fakulta stavební, Ústav vodních staveb, Laboratoř vodohospodářského výzkumu, Veveří 95, 602 00 Brno, Česká republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 143 - 150, doi:
Scientific Paper, Slovak

Katarína Kotríková, Kamila Hlavčová: Evaluation of the accuracy of MODIS satellite images on the upper Hron river basin

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• Monitoring and modelling snow accumulation and snow melting in mountainous catchments is rather complicated, especially for a high spatial variability of snow characteristics and limited availability of terrestrial hydrological data. Nowadays satellite data which are not dependent on spatial variability of terrain characteristics, represent an alternative to the terrestrial data. Spatial information on snow cover is available from the MODIS satellites in a daily time step and a spatial resolution of 500 m. This paper focuses on validation of snow cover images from MODIS on measured data in 5 climatic stations in the upper Hron river basin in the period 2000-2010. Limitation of accuracy caused by the presence of clouds was first reduced by combining Terra and Aqua sensors, then by spatial and temporal data filters. Effect of both filters on increasing accuracy of the satellite snow data were compared and discussed.
  
  KEY WORDS: MODIS, snow cover, spatial fitlering, temporal filtering
  
  Address:
  - Katarína Kotríková, Katedra vodného hospodárstva krajiny, Stavebná fakulta Slovenskej technickej univerzity v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: katarina.kotrikova@stuba.sk)
  - Kamila Hlavčová, Katedra vodného hospodárstva krajiny, Stavebná fakulta Slovenskej technickej univerzity v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 151 - 160, doi:
Scientific Paper, Slovak

, Ján Pekár: Identification of long-term periods of the discharge time series variability by the CEEMDAN method

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• The aim of the paper is the identification long-term periods volatility flow time series of the Danube, Vah and Hron rivers. A better understanding of the flow fluctuations is important for flood control planning, river transport and others. We have worked with monthly flows for 133 years (1596 measurements) for the Danube River, 78 years (936 measurements) for the river Hron and for the Vah 88 years (1056 measurements) period. In the paper time series of flows of Danube, Vah and Hron rivers were decomposed to IMF components by the modified EMD (Empirical Mode Decomposition, Huang (1998)) method CEEMDAN (Complete and Ensemble Empirical Mode Decomposition with Adaptive Noise, (Torres, 2011)). It was shown that correlations between the IMF components of these series indicate that part of the variance can probably be explained by the same climatic events.
  
  KEY WORDS: hydrological variability, Ensemble Empirical Mode Decomposition, adaptive noise, residuals, time series of flows
  
  Address:
  - Ondrej Marušiak, - Ján Pekár, Katedra aplikovanej matematiky a štatistiky, Fakulta matematiky, fyziky a informatiky UK, Mlynská dolina, 842 48 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 161 - 170, doi:
Scientific Paper, Slovak

Katarína Jeneiová, Miroslav Sabo, Silvia Kohnová: Trend detection in long term maximum annual discharge series in catchments of Slovakia

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• The main objective of the study was to find the trend in the annual maximum discharge series in the area of Slovak Republic. Calculations were performed on data obtained from 53 gauging stations with minimum lengths of the observations of 60 years. Homogeneity of the time series was tested by a non-parametric Alexandersson test (1986) for single shift at 5% level of significance. The Mann-Kendall trend test correction for autocorrelated data was used to test the significance of detected trend. The time series were analysed at different lengths of 60 years and whole observed time period at levels of significance of 5, 10 and 20%. Results were displayed spatially on the map of Slovakia. Statistically significant decreasing trend in the annual maximum discharge series was found in the catchments of East and Middle Slovakia.
  
  KEY WORDS: homogeneity, trend tests, maximum annual discharge series
  
  Address:
  - Katarína Jeneiová, Katedra vodného hospodárstva krajiny, Stavebná fakulta Slovenskej technickej univerzity v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: katarina.jeneiova@stuba.sk)
  - Miroslav Sabo, Katedra matematiky a deskriptívnej geometrie, Stavebná fakulta Slovenskej technickej univerzity v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Silvia Kohnová, Katedra vodného hospodárstva krajiny, Stavebná fakulta Slovenskej technickej univerzity v Bratislave, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 171 - 177, doi:
Scientific Paper, Slovak

Patrik Sleziak: Discharge time series analysis of selected Slovak rivers by wavelet transform

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• Nowadays, in water management is coming to the fore the issue of changes in trends of hydrological and climatological time series. The study of these changes must be based on a statistical analysis of time series recorded in history. The processing of such data is based on new methods of statistics and mathematical analysis. This paper deals with the analysis of time series of average annual flows using wavelet transform. In the first part we made introduction to spectral analysis of time series and information about WT. In the practical part we used the WT for the analysis of time series of flows. The aim of the paper was to show cyclical component and multi – annual variability of the time series. The results were processed in a software environment R.
  
  KEY WORDS: time series, wavelet transform, spectral analysis
  
  Address:
  - Patrik Sleziak, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.:+421908 965 784 Fax.: Email: patrik.sleziak@stuba.sk)

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 178 - 185, doi:
Scientific Paper, Slovak

Roman Výleta, Ján Szolgay: Stochastic simulation of average daily air temperatures in the river Hron catchment for the needs of flood frequency analysis

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• There are a lot of statistical methods dealing with the modelling of average daily air temperatures. However, most of them simulate the air temperature independently from other meteorological variables. Average daily air temperatures play an important role in the rainfallrunoff modelling process, which can also be used to generate long synthetic time series of flows within the deterministic-stochastic modelling approach. It is necessary to model this variable as a function of precipitation occurrence. This paper presents a method which enables to simulate average daily air temperatures as a function of precipitation occurrence. The temperature model is based on Markov processes, which are used for stochastic simulation of synthetic series of average daily air temperature residuals of arbitrary length. The model also utilizes Fourier series of the 2nd harmonic to simulate average daily air temperatures. The methodology was tested in the conditions of mountainous catchment of the Hron River with the outlet at Banská Bystrica.
  
  KEY WORDS: stochastic modeling of average daily air temperatures, Markovian generating processes, Fourier series of the j-th harmonic
  
  Address:
  - Roman Výleta, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.:+4212 59274 498 Fax.: +4212 52923 575 Email: roman.vyleta@stuba.sk)
  - Ján Szolgay, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 186 - 193, doi:
Scientific Paper, Slovak

Peter Rončák, Kamila Hlavčová, Zuzana Štefunková: Transfer of parameters in a distributed rainfall-runoff model

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• Rainfall-runoff models with spatially distributed parameters are now a widely used tool to estimate the impact of runoff changed conditions, such as changes of land use and climate. While the modeling of climate change are often based on conceptual models, for modeling land use changes, it is necessary to use rainfall-runoff models with physical based spatially distributed parameters. The properties of vegetation or surface cover are characterized by parameters of vegetation and model reliability also depends on accuracy these parameters can be estimated, in the rainfall-runoff models with spatially distributed parameters. The aim of paper was comparison between simulated runoff and water balance components in three different types of land use in 1990, 2000, 2012 in the Upper Hron River basin. Simulation period was from 1981 to 2010, in which global model parameters for different land use patterns were calibrated and validated. The work has been tested transfer WetSpa model global parameters for different land use, as well as changes in runoff in the final profile and alteration the soil moisture simulated in three different sorts of land use.
  
  KEY WORDS: transfer of model parameters, distributed rainfall-runoff WetSpa model
  
  Address:
  - Peter Rončák, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: peter.roncak@stuba.sk)
  - Kamila Hlavčová, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Zuzana Štefunková, Katedra hydrotechniky, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 194 - 203, doi:
Scientific Paper, Slovak

Beata Karabová: Testing the possibility of parameters regionalization of SCS-CN method – for lowland areas of Slovakia

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• This paper is devoted to analysis of the Curve Number method (also known as Soil Conservation Service – Curve Number method (SCS - CN - method). The aim of this study was to test our new concept of the original SCS -CN method. The new concept uses three classes, the class K1, K2, K3, and K4, according to statistical characteristics of measured data. In the study, we used four new classifications based on different sorting parameters. This paper compares the parameters obtained by the SCS – CN method according to the original methodology with its modified version. We determined CN numbers and initial abstraction coefficient λ empirically for each rainfall- runoff event. The presented modified SCS -CN method was tested on five lowland catchments of Slovakia. The result of the study is an empirical regional runoff curve for direct runoff depth determination, suitable for this area. Our analyses show that the original methodology significantly overestimates the simulated direct runoff depths. Single rainfall- runoff events of measured data are found to be in relatively large range between antecedent moisture conditions curves AMC I and III, However, using the original methodology more than 85 % of all rainfallrunoff events falls PVP in category I.
  
  KEY WORDS: Curve Number method (SCS-CN method), initial abstraction coefficient, parameter’s regionalization, antecedent moisture conditions (AMC), rainfall – runoff event (R-R)
  
  Address:
  - Beata Karabová, Katedra vodného hospodárstva krajiny, SvF, STU, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: beata.karabova@stuba.sk)

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 204 - 212, doi:
Scientific Paper, Slovak

Beáta Hamar Zsideková, Silvia Kohnová, Kamila Hlavčová: Analysis of time changes in the characteristics of the hydrological balance on the Laborec basin

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• Using a rainfall - runoff models and climate scenarios we can better assess possible changes occurring in the hydrological process. Data on hydrological variables such as runoff, precipitation and air temperature are important in predicting hydrological phenomena. In this work were used time series of the hydrological balance components created using mathematical modeling the outcomes of regional climate models Remo 5.7 and Aladin - Climate in the timeframe 2021-2050 and 2071-2100. For the mathematical modeling the elements of the hydrological balance was used conceptual rainfall - runoff model Hron in daily time step, developed by the Department of Land and Water Resources Management in Bratislava. To assess changes in the components of the hydrological balance (runoff, snow water equivalent and soil moisture) in the next decade was used trend analysis. For the testing the statistical significances of the trends Mann - Kendall nonparametric test was used.
  
  KEY WORDS: rainfall - runoff model Hron, trend analysis, Mann – Kendall test
  
  Address:
  - Beáta Hamar Zsideková, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: beata.zsidekova@stuba.sk)
  - Silvia Kohnová, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Kamila Hlavčová, Katedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 213 - 222, doi:
Scientific Paper, Slovak

Zuzana Štefunková, Kamila Hlavčová, Peter Valent: An assessment of the impact of climate change on the upper Hron river basin based on the results of the simulation of three hydrological models

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• This article deals with the issue of the potential impact of climate change on the changes in runoff for the next decades on the Hron River basin with an outlet in Banská Bystrica. For modeling mean monthly discharges three rainfall-runoff models were applied: the KVHK model in a monthly time-step, the Hron model and a new version of the Hron model, Hron 1.3, in a daily time step. Changes in climatic characteristics were expressed according to the outputs of the Dutch regional climate model KNMI and the emission scenario A1B. The quality of the calibration of different hydrological models was evaluated by comparing the simulated and measured mean daily discharges for the reference period 1961-1990 the basin’s outlet. Calibrated parameters of different hydrological rainfall-runoff models were used to simulate mean daily discharges for changed climate outputs according to the KNMI regional climate model for the period 1961-2100. Based on the results a reliability of the prediction of the climate change conditions according to the chosen scenario has been discussed and the changes in mean monthly discharges in the future time periods comparing to the reference period 1961-1990 have been evaluated.
  
  KEY WORDS: model KVHK, model Hron, model KNMI, climate change, charges in runoff
  
  Address:
  - Zuzana Štefunková, Katedra hydrotechniky, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika (Corresponding author. Tel.: Fax.: Email: zuzana_stefunkova@stuba.sk;zuzana_stefunkova@yahoo.com)
  - Kamila Hlavčová, Ktedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika
  - Peter Valent, Ktedra vodného hospodárstva krajiny, Stavebná fakulta STU, Radlinského 11, 813 68 Bratislava, Slovenská republika

Acta Hydrologica Slovaca, Vol. 15, No. 1, 2014, p. 223 - 226, doi:
Scientific Paper, Slovak

Dana Pavelková, Ladislav Holko: Completion of infrastructure of hydrological research stations

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• Institute of Hydrology, Slovak Academy of Sciences Bratislava, gained as a principal investigator through its field offices in Michalovce and Liptovský Mikuláš a project entitled "Completion of infrastructure of hydrological research stations" ( DIHYS ). The project is financed by the EU Structural Funds. A strategic objective of the project is to improve a technical infrastructure of hydrological research stations and the reinforcement of excellent hydrological research capacity. The project has two specific objectives while each of them is aimed at one activity. The first specific objective is to modernize and improve the technical infrastructure of lowland hydrology research station. The activity within this specific objective is the enhancement of lowland hydrology research station. The aim of this activity is to complete the infrastructure of technical equipment in Michalovce research station in order to perform a complex monitoring of hydrological processes in lowland areas. The most important outcome will be the construction of lysimeter station which enables a detailed research of the movement of water and substances in porous media and its interactions with the environment. The second specific objective is to modernize and improve the technical infrastructure of mountain hydrology research station. The activity within this specific objective is the enhancement of mountain hydrology research station. The aim of this activity is to complete the infrastructure of technical equipment in Liptovský Mikuláš research station in order to perform a complex monitoring of hydrological processes in mountain areas, focusing on the outflow formation. The most important outcome will be the construction of isotope laboratory which enables the measurement of stable isotopes of oxygen and hydrogen, as well as the year-round monitoring of atmospheric precipitation in mountain river basin and the possibility of a geophysical and photogrammetric exploration of the river basin characteristics
  
  KEY WORDS: hydrological research
  
  Address:
  - Dana Pavelková, Výskumná hydrologická základňa ÚH SAV, Hollého 42, 071 01 Michalovce, Slovenská republika (Corresponding author. Tel.:00421 56 6425 147 Fax.: Email: pavelkova@uh.savba.sk)
  - Ladislav Holko, Experimentálna hydrologická základňa ÚH SAV, Ondrašovská 16, 031 05 Liptovský Mikuláš, Slovenská republika