Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 9 - 18, doi: 10.31577/ahs-2020-0021.01.0002
Scientific Paper, English

Dana Halmová, Pavla Pekárová: Runoff regime changes in the Slovak Danube River tributaries

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  • This paper deals with a statistical analysis of changes in the hydrological regime of Slovak tributaries of the Danube River at 11 stations over two 30-year periods: 1931–1960 and 1986–2015. We analyzed changes in monthly discharges using the Pardé coefficient method, as well as changes in average daily discharges. The monthly Pardé coefficients may be used to plot so-called regime curves. Their course is essentially determined by the monthly water balances in the catchments, as well as by intra-annual storage effects like snow accumulation and snowmelt. Changes in the course of Pardé coefficients for water stations of Slovak tributaries of the Danube River do not show any major changes, except for the Ipeľ-Holiša and Topľa-Hanušovce stations. From the results of the daily flow rate analysis it is clear that the course of daily flow rates in the monitored stations remains unchanged during the year and in the most of the monitored Slovak stations the daily flow rates decrease, except for the water stations Belá-Podbanské and Váh-Liptovský Mikuláš.

    KEY WORDS: intra-annual flow regime, PARDÉ coefficient, daily and monthly discharge, Slovak Danube tributaries

    Address:
    - Dana Halmová, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: halmova@uh.savba.sk))
    - Pavla Pekárová, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 19 - 28, doi: 10.31577/ahs-2020-0021.01.0003
Scientific Paper, English

Jakub Mészáros, Pavla Pekárová, Ján Pekár: Estimation of discharge with long return period using historical flood records

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  • Records of historical catastrophic floods provide extremely valuable knowledge about the frequency of occurrence of such events on the rivers that do not have a series of discharge observations long enough, or observations are completely absent. In this paper we present knowledge about historical floods on the Teplica River in Sobotište and its catchment. Based on statistical processing of the series of maximum annual discharge from the water gauge Sobotište-Teplica, we present the impact of the inclusion of historical floods on the estimation of the T-year design discharge values.

    KEY WORDS: historical floods, T-year values, LP3 distribution, Teplica River

    Address:
    - Jakub Mészáros, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: hydrjaku@uh.savba.sk)
    - Pavla Pekárová, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic
    - Ján Pekár, Comenius University in Bratislava, Faculty of Mathematics, Physics, and Informatics, Department of Applied Mathematics and Statistics, Mlynská dolina, 842 48 Bratislava Slovak Republic

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 29 - 38, doi: 10.31577/ahs-2020-0021.01.0004
Scientific Paper, English

Veronika Bačová Mitková: Bivariate joint probability analysis of flood hazard at river confluence

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  • Assessing the statistical significance of floods in the complex hydrological conditions that exist at the confluence of the main river and its tributaries, as well as the choice of hydrological design parameters for flood protection in these areas is one of the main tasks in the current hydrology. The main aim of this paper is a joint bivariate frequency analysis of annual peak discharges and synchronously occurred maximum discharges at the main river and its tributary. The annual maximum and daily maximum discharges of the Morava River, as main river, and its tributary Myjava River were analysed. We selected the most appropriate copula function for our bivariate analysis. Selected copulas were used to illustrate the joint occurrence probabilities and joint return periods of the discharge pairs and consequently to determine the joint probabilities of measured discharges. Results of such analyses provide comprehensive information about flood situations where a devastating effect may be increased in the case were floods occur at the same time on the main river and its tributary. And at the same time, the results obtained by the bivariate analysis of the variables which characterize the hydrological regime can contribute to a more reliable assessment of the flood risks.

    KEY WORDS: maximal mean daily discharge, annual peak discharges, corresponding discharge, joint probability distribution, copula function.

    Address:
    - Veronika Bačová Mitková, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: mitkova@uh.savba.sk)

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 48 - 55, doi: 10.31577/ahs-2020-0021.01.0006
Scientific Paper, English

Pavla Pekárová, Pavol Miklánek, Ján Pekár, Zuzana Danáčová: Long-term development of discharge and nitrate concentrations in the Little Carpathians headwaters

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  • One of the requirements imposed by the Water Framework Directive 2000/60/EC (WFD, 2000) is to analyze and predict long-term evolution of surface water quality parameters. During 28-years period (1991–2018), the concentrations of selected pollutants were monitored in the Little Carpathians headwater basins by the Institute of Hydrology, SAS. In this study we analyse the long-term development of runoff and nitrates nitrogen concentrations in the Parná River at Horné Orešany water gauge station during the period 1991–2018. Discharges in the Parná River decreased slightly, but the trend is not statistically significant. In the case of nitrate nitrogen concentrations the marked decrease occurred in this river basin from the value of 5.11 mg l-1 during the years 1991–1995 to the value of 2.49 mg l-1 in the years 2015–2018. The relation between discharge and nitrate concentration was used to derive exponential empirical relations for estimation of the nitrate nitrogen concentrations in the stream based on mean daily discharge during the sampling day. These equations can be used for indirect estimation of nitrate nitrogen concentrations when they were not measured directly

    KEY WORDS: runoff, discharge variability, nitrate, long term trends

    Address:
    - Pavla Pekárová, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: pekarova@uh.savba.sk))
    - Pavol Miklánek, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic
    - Ján Pekár, Comenius University in Bratislava, Faculty of Mathematics, Physics, and Informatics, Department of Applied Mathematics and Statistics, Mlynská dolina, 842 48 Bratislava
    - Zuzana Danáčová, Slovak Hydrometeorological Institute, Jeséniova 17, 833 15 Bratislava Slovak Republic

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 56 - 64, doi: 10.31577/ahs-2020-0021.01.0007
Scientific Paper, English

Cyril Siman, Yvetta Velísková: Impact of different proportion of agricultural land in river catchments on nitrogen surface streams pollution

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  • Water quality is threatened particularly in regions where the agricultural landscape is prevailing. This study presents results of the comparison of yearly total nitrogen emissions and contribution of different emission pathways on this emissions into surface streams for three river catchments in Slovakia territory with the contrasting proportion of agricultural land to the total area of the river catchment. For nitrogen yearly emissions and pathways detection, the numerical model MONERIS has been used. Results indicate that in river catchments with a higher proportion of agricultural land higher contribution of nitrogen emission carried out mainly via groundwater (especially in lowland), but also via agricultural erosion and drainage system.

    KEY WORDS: water quality, surface stream, nitrogen emission, MONERIS, river catchment

    Address:
    - Cyril Siman, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: siman@uh.savba.sk)
    - Yvetta Velísková, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 74 - 81, doi: 10.31577/ahs-2020-0021.01.0009
Scientific Paper, English

Lucia Balejčíková, Andrej Tall, Branislav Kandra, Dana Pavelková: Relationship of nitrates and nitrites in the water environment with humans and their activity

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  • Nitrates and nitrites in water pose a health and environmental hazards, in particular when exceeding limits defined in the European Union, i.e. max. 50 mg l-1 of nitrates. It is not recommended to exceed the limit of 10 mg l-1 of nitrates for infants and children. The maximum concentration of nitrites is 0.5 mg l-1 for adults and infants less than 0.1 mg l-1. Our work offers a review of the water quality concerning the relationship between nitrates/nitrites and humans. Basic properties and forms of nitrates, their use for human activities, importance and risks to human health and possibilities of their physicochemical determination are summarized. Our study demonstrates also the novel approaches to the nitrates decontamination in a water environment using various nanomaterials. We aimed at a collection of records from the monitoring of nitrates in selected areas in Slovakia to show good quality of water in various water sources, which over time improves due to the increasingly low fertilization intensity and thus of agriculture production, which is gradually being replaced by imports.

    KEY WORDS: nitrates/nitrites, importance/risk, determination, decontamination, monitoring

    Address:
    - Lucia Balejčíková, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: balejcikova@uh.savba.sk)
    - Andrej Tall, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic
    - Branislav Kandra, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic
    - Dana Pavelková, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 82 - 88, doi: 10.31577/ahs-2020-0021.01.0010
Scientific Paper, English

Štefan Rehák, Peter Stradiot, Karol Kňava, Ľubica Kopčová, Viliam Novák: Method of wetlands water regimen diagnosis

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  • Wetlands are territories, permanently or temporary waterlogged; temporary waterlogging must cover majority of the season. Wetlands are ecosystems typical by maximum (potential) evapotranspiration with high solar energy consump-tion; therefore, they are important as local climate stabilizers. In this paper, method of wetland water regimen diagnosis is described, applicable to wetlands with so called autonomous water regimen. It means, that wetland water regimen is formed mostly by precipitation and (potential) evapotranspiration; such wetlands are hydrodynamically isolated from its neighbourhood. This is typical for majority of wetlands in Slovakia. Method of diagnosis is based on evaluation of water fluxes to and out of the wetland and is illustrated on three typical wetlands.

    KEY WORDS: waterlogging, precipitation, potential evapotranspiration, wetland management

    Address:
    - Štefan Rehák, Institute of Water Resources Research, Nábrežie arm. gen. L. Svobodu 5, 812 49 Bratislava 1 (Corresponding author. Tel.: Fax.: Email: rehak@vuvh.sk)
    - Peter Stradiot, Institute of Water Resources Research, Nábrežie arm. gen. L. Svobodu 5, 812 49 Bratislava 1
    - Karol Kňava, Institute of Water Resources Research, Nábrežie arm. gen. L. Svobodu 5, 812 49 Bratislava 1
    - Ľubica Kopčová, Institute of Water Resources Research, Nábrežie arm. gen. L. Svobodu 5, 812 49 Bratislava 1
    - Viliam Novák, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 89 - 97, doi: 10.31577/ahs-2020-0021.01.0011
Scientific Paper, English

Zuzana Műnsterová, Jana Pařílková, Jan Mikulka, Jan Dušek: Reconstruction of electric impedance field of soil with clay anomaly

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  • Electrical impedance characterizes the properties of the examined environment when passing through an alternating electric current. The paper is based on the dependence of the course of real and imaginary components of electrical impedance on the humidity of the porous environment. Different soil environments have various water retention capacities under the same hydrometeorological conditions. This hydrophysical characteristic is used in the presented paper to study the inhomogeneity of the porous environment. The contribution is beneficial in that it proposes a method which, based on simple measurements, allows to evaluate the homogeneity of the porous environment. The method is widely used in water management (e.g. determination of failures of sealing cores in earth dams and dams) but also in hydrological survey and monitoring (e.g. determination of volume humidity).

    KEY WORDS: clay, soil, probe, electrical impedance, Z-meter device

    Address:
    - Zuzana Műnsterová, Brno University of Technology, Faculty of Civil Engineering, Institute of Water Structures, Veveří 95, 602 00 Brno, Czech Republic (Corresponding author. Tel.: Fax.: Email: munsterova.z@fce.vutbr.cz)
    - Jana Pařílková, Brno University of Technology, Faculty of Civil Engineering, Institute of Water Structures, Veveří 95, 602 00 Brno, Czech Republic
    - Jan Mikulka, Brno University of Technology, Faculty of Electrical Engineering and Communication, Department of Theoretical and Experimental Electrical Engineering, Technická 3082/12 616 00 Brno, Czech Republic
    - Jan Dušek, Brno University of Technology, Faculty of Electrical Engineering and Communication, Department of Theoretical and Experimental Electrical Engineering, Technická 3082/12 616 00 Brno, Czech Republic

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 113 - 122, doi: 10.31577/ahs-2020-0021.01.0014
Scientific Paper, English

, Michaela Červeňanská, Andrej Šoltész: Assessment of the impact of proposed cut-off walls on ground-water level regime during extreme hydrological conditions

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  • The capacity of rivers Váh, Small Danube and the deviation of river Nitra, located in Slovakia, is sufficient in terms of transferring flood flow rates, however defects occur during long-lasting flood situations. If the problem is ignored, different processes may eventually endanger the adjacent territory or may lead to contamination of water and soil as a result of flooding a nearby sewage treatment plant. For these reasons an additional sealing of dykes was proposed. The article deals with the impacts of suspended cut-off walls on groundwater flow and level regime in a wider area for both steady and unsteady scenarios.

    KEY WORDS: cut-off wall, numerical simulation, groundwater, flood, TRIWACO

    Address:
    - Dana Baroková, - Michaela Červeňanská, - Andrej Šoltész

     




Acta Hydrologica Slovaca, Vol. 21, No. 1, 2020, p. 123 - 129, doi: 10.31577/ahs-2020-0021.01.0015
Scientific Paper, English

Radoslav Schügerl, Yvetta Velísková, Valentín Sočuvka, Renáta Dulovičová: Effect of aquatic vegetation on Manning´s roughness coefficient value – Case study at the Šúrsky channel

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  • Vegetation growing in the water along watercourses has been the subject of several studies since it was recognized that it could have a significant impact on the water flowIncreased bed roughness caused by aquatic vegetation is a very often phenomenon in case of flow in natural open channel during the growing season. Vegetation impedes the water flow and may increase flood risks. Thus, determining the effect of aquatic vegetation on flow conditions in streams is very important for estimation of hydrodynamics in natural streams. Occurance of aquatic vegetation is more often in case of lowland streams. The purpose of this paper is to investigate and determine how aquatic vegetation influences flow resistance, water depth and discharge in the Šúrsky channel at the Podunajská lowland area. Measurements performed during three various times of year 2019 at this stream were used for an evaluation of vegetation impact on flow conditions in this stream. The Manning´s coefficient was used as one way of quantifying this impact. The results show variation of this parameter during the winter and summer season.

    KEY WORDS: aquatic vegetation, water-level, discharge, Manning´s roughness coefficient

    Address:
    - Radoslav Schügerl, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: schugerl@uh.savba.sk)
    - Yvetta Velísková, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic
    - Valentín Sočuvka, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic
    - Renáta Dulovičová, Institute of Hydrology SAS, Dúbravská cesta č. 9, 841 04 Bratislava, Slovak Republic

     




AHS Editorial Office
Institute of Hydrology SAS
Dúbravská cesta 9
841 04 Bratislava
Slovak Republic
web: www.ih.sav.sk/ah
email: Yvetta.Veliskova@savba.sk

Journal of Hydrology and Hydromechanics
Institute of Hydrology SAS
Dúbravská cesta 9
841 04 Bratislava
Slovak Republic
web: www.ih.sav.sk/jhh

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