Institute of Mathematical Machines and Systems Problems NAS of Ukraine

Kiev, Ukraine

Institute of Mathematical Machines and Systems Problems NAS of Ukraine

Kiev, Ukraine
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Kovalets I.V.,Institute of Mathematical Machines and Systems Problems NAS of Ukraine | Kovalets I.V.,Ukrainian Center of Environmental and Water Projects | Korolevych V.Y.,Chalk River Laboratories | Khalchenkov A.V.,Institute of Mathematical Machines and Systems Problems NAS of Ukraine | And 5 more authors.
Atmospheric Environment | Year: 2013

The impact of diagnostic wind field model on the results of calculation of microscale atmospheric dispersion in moderately complex terrain conditions was investigated. The extensive radiological and meteorological data set collected at the site of the research reactor of the Chalk River Laboratories (CRL) in Canada had been compared with the results of calculations of the Local Scale Model Chain of the EU nuclear emergency response system JRODOS. The diagnostic wind field model based on divergence minimizing procedure and the atmospheric dispersion model RIMPUFF were used in calculations. Taking into account complex topography features with the use of diagnostic wind field model improved the results of calculations. For certain months, the level of improvement of the normalized mean squared error reached the factor of 2. For the whole simulation period (January-July, 2007) the level of improvement by taking into account terrain features with the diagnostic wind field model was about 9%. The use of diagnostic wind field model also significantly improved the fractional bias of the calculated results. Physical analysis of the selected cases of atmospheric dispersion at the CRL site had been performed. © 2013 Elsevier Ltd.


Kantardgi I.G.,Moscow State University of Civil Engineering | Kivva S.L.,Institute of Mathematical Machines and Systems Problems NAS of Ukraine | Shunko N.V.,Moscow State University of Civil Engineering
Magazine of Civil Engineering | Year: 2014

A numerical model of surface wave movement and water filtration in saturated-unsaturated porous medium has been developed. The model can be used to define the parameters of the wave run-up on the slope protected with a permeable fixed layer. The model is applied to determine positions of the free wave surface at the different times, including such parameters as the height of wave run-up and wave run-down on the slope. In addition, both flow velocity field in the upper protected layer and moisture distribution in the soil body of the slope were defined. The model is verified with the results of the published large-scale tests that have been conducted at Technical University Braunschweig in the wave flume with the slopes protected according to Elastocoast technology. The numerical model can be applied to calculate the run-up of extreme waves on protected engineering and beach slopes in natural conditions.


Kovalets I.V.,Institute of Mathematical Machines and Systems Problems NAS of Ukraine | Kovalets I.V.,Ukrainian Center of Environmental and Water Projects | Kivva S.L.,Institute of Mathematical Machines and Systems Problems NAS of Ukraine | Udovenko O.I.,Institute of Mathematical Machines and Systems Problems NAS of Ukraine
Natural Hazards | Year: 2015

The mesoscale meteorological/distributed hydrological model chain WRF/DHSVM was calibrated for simulation of extreme flood events in Uzh River basin in Ukrainian Carpathians. The flood event which happened in July 2008 was successfully reproduced by using final analysis meteorological input data of the US National Centers for Environmental Prediction (NCEP). For climate run for the period of 1960–1990, the NCEP Reanalysis-1 meteorological data were used. Frequencies of extreme precipitation events obtained by fitting of the measured and simulated precipitation time series with the generalized extreme value distribution were very close. Simulated water discharges for the very extreme floods happening from once per 50 to once per 100 years were in good agreement with the water discharges of the same frequencies obtained by statistical processing of measurements. © 2014, Springer Science+Business Media Dordrecht.

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