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1

Przepływ w kanałach otwartych z pokrywą lodową

Majewski Wojciech

Gospodarka Wodna

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2022

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Nr 12

5--12

PL

W artykule przedstawiono podstawowe charakterystyki hydrauliczne dla przepływu ustalonego z pokrywą lodową, wpływ pokrywy lodowej na rozkład prędkości w przekroju przepływu oraz charakter rozkładu prędkości w pionie pod pokrywą lodową. Przedstawiono sposób określenia współczynnika szorstkości dolnej powierzchni pokrywy lodowej na podstawie pomierzonego rozkładu prędkości w przepływie pod lodem. Podano sposoby obliczania natężenia przepływu przy danym stanie wody i znanej charakterystyce pokrywy lodowej. Rozważania te poparte są konkretnymi przykładami obliczeniowymi.

EN

The article presents the basic hydraulic characteristics of a steady flow with ice cover, the impact of ice cover on the velocity distribution in the flow cross-section and the character of vertical velocity distribution under the ice cover. It presents the method of determining the ice cover bottom surface roughness coefficient, based on the measured velocity distribution in the flow under the ice. It lists the methods of the flow intensity calculation at a given river stage and known ice cover characteristic. These considerations are illustrated with calculation examples.

2

The Lower Vistula and Its Ice Problems

Majewski Wojciech

Archives of Hydro-Engineering and Environmental Mechanics

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2021

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Vol. 68, nr 1

41--83

EN

In many countries of the northern hemisphere during winter period ice forms appear on various water bodies, which results in significant changes of physical, chemical and ecological conditions. These changes are different in rivers, channels, lakes or once-through reservoirs. On the terrain of Poland ice always caused considerable problems affecting intensive inland navigation and other river use. These problems appeared especially on the Vistula River, which in 17th and 18th century was one of the most navigable rivers in Europe. The Vistula is the largest Polish river, which flows from the south in the Carpathian Mountains to the Baltic Sea in the north. It is the second largest river, after Neva, of the Baltic Sea catchment. The length of the Vistula is 1047 km and its catchment amounts to 194 thousand km2. The predominant part of the Vistula river basin (87%) is now on Polish territory and the remaining (13%) catchment is in Belarus, Ukraine and Slovakia. The course of the Vistula can be divided into three distinctly different sections: upper, middle and lower. These river sections have appropriate catchments with their tributaries. There are hydraulic structures on the main river course and on its tributaries which serve navigation, hydroenergy, flood protection, water supply and recreation. All over the Vistula catchment there are frequent floods during spring and summer time resulting from excessive precipitation but in winter caused by ice phenomena. Numerous flow problems appear especially along the lower Vistula course because of ice phenomena and they result very often in severe flood problems. The Vistula has a very variable time and spatial discharge, because of existing climate conditions over its catchment. The aim of the paper is to present hydraulic and hydrologic characteristics of the Lower Vistula river with special emphasis on the management of this river section for navigation, hydroenergy, flood protection and water supply in view of ice phenomena appearing there. Information concerning changes of water characteristics due to various water temperatures are presented as well as on the formation of various forms of ice in flowing water. Numerous ice studies were carried out in Poland and especially on the Lower Vistula section as it was very ice prone and where many ice jams and ice-jam floods occurred. A special hydraulic situation existed at the mouth of the Vistula, which caused important floods in the 18th century and resulted in the construction of a special direct channel to the sea (Przekop Wisły) solving flood problems in this area. Information is presented on changes in open channel flow due to the appearance of ice cover and other ice forms. The paper includes ample information on the run, consequences and studies connected with a very important ice-jam-flood on the upper part of Włocławek reservoir in 1982.

3

Flow in open channels under the influence of ice cover

Majewski W.

Acta Geophysica

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2007

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Vol. 55, no. 1

11-22

EN

During winters in Poland, lakes, ponds, rivers, channels, run-of-reservoirs, ditches and streams are covered with ice, which changes significantly the flow and thermal conditions in water bodies. The paper presents a very complicated process of ice formation on stagnant and flowing waters. Various kinds of ice are described together with their consequences for flow and thermal conditions. The possibility to define flow conditions in open channels with ice cover is described. In 1982, a significant flood on Włocławek Reservoir (Lower Vistula River) appeared, which was caused by the coincidence of unfavourable, extreme hydrological and meteorological conditions. These conditions, as well as the run and consequences of the flood, are described. Detailed field measurements of ice cover and flow were carried out. One-dimensional model for steady nonuniform flow was developed and applied to the conditions existing in 1982 on the Włocławek Reservoir.