Unified structural approach to linear flood routing     

Zbigniew W. Kundzewicz  James C.I. Dooge 《Advances in water resources》1985,8(1):37-43

The structural theory of linear systems, which allows the non-homogeneous initial and boundary conditions to be expressed as part of a generalised system input, is applied to the problem of linear flood routing. The standardising functions needed to accomplish this are derived for three methods of lumped hydrologic flood routing (lag and route, Muskingum and Kalinin-Milyukov) and to three methods of distributed hydraulic flood routing (kinematic wave and two simplified forms of the linear St. Venant model). The appropriate Green's functions needed to complete the solution for these six cases are also presented.  相似文献   

Summer Floods in Central Europe – Climate Change Track?     

Zbigniew W. Kundzewicz  Uwe Ulbrich  Tim brücher  Dariusz Graczyk  Andreas Krüger  Gregor C. Leckebusch  Lucas Menzel  Iwona Pińskwar  Maciej Radziejewski  Małgorzata Szwed 《Natural Hazards》2005,36(1-2):165-189

In Central Europe, river flooding has been recently recognized as a major hazard, in particular after the 1997 Odra /Oder flood, the 2001 Vistula flood, and the most destructive 2002 deluge on the Labe/Elbe. Major recent floods in central Europe are put in perspective and their common elements are identified. Having observed that flood risk and vulnerability are likely to have grown in many areas, one is curious to understand the reasons for growth. These can be sought in socio-economic domain (humans encroaching into floodplain areas), terrestrial systems (land-cover changes – urbanization, deforestation, reduction of wetlands, river regulation), and climate system. The atmospheric capacity to absorb moisture, its potential water content, and thus potential for intense precipitation, are likely to increase in a warmer climate. The changes in intense precipitation and high flows are examined, based on observations and projections. Study of projected changes in intense precipitation, using climate models, for several areas of central Europe, and in particular, for drainage basins of the upper Labe/Elbe, Odra/Oder, and Vistula is reported. Significant changes have been identified between future projections and the reference period, of relevance to flood hazard in areas, which have experienced severe recent floodings.  相似文献   

Fractal analysis of flow of the river Warta     

Maciej Radziejewski  Zbigniew W. Kundzewicz   《Journal of Hydrology》1997,200(1-4):280-294

A long time series (170 years) of daily flows of the river Warta (Poland) are subject to fractal analysis. A binary variable (renewal stream) illustrating excursions of the process of flow is examined. The raw series is subject to de-seasonalization and normalization. Fractal dimensions of crossings of Warta flows are determined using a novel variant of the box-counting method. Temporal variability of the flow process is studied by determination of fractal dimensions for shifted horizons of 10 or 30 years length. Spectral properties are compared between the time series of flows, and the fractional Brownian motion which describes both the fractal structure of the process and the Hurst phenomenon. The approach may be useful in further studies of non-stationary of the process of flow, analysis of extreme hydrological events and synthetic flow generation.  相似文献   

Local similarity in the convective boundary layer (CBL)   总被引：1，自引：0，他引：1  

Zbigniew Sorbjan 《Boundary-Layer Meteorology》1988,45(3):237-250

The paper presents similarity hypotheses that in the CBL the structure of turbulence is described by two different sets of local scales, defined by local (z-dependent) values of governing parameters. Arguments for local scaling are presented and the form of the similarity functions is derived.  相似文献   

On the reliability of tower-shaped structures under seismic excitations     

Zbigniew Zembaty 《地震工程与结构动力学》1987,15(6):761-775

This paper considers the problem of random vibrations and the reliability of slender tower-shaped structures subjected to seismic excitations. Applying the concept of evolutionary spectra and the uniformly modulated random process as a model of strong ground motion, the response statistics are derived. Peak response values and reliability are then estimated. Results are related to Modified Mercalli and Arias intensities. With the aid of the Fast Fourier Transform technique a numerical analysis of peak response and reliability of a high-rise reinforced concrete chimney has been carried out. Results indicate the location of seismic failures in the upper half of the shaft of the chimney. Finally, the paper briefly examines the influence of strong motion duration on the peak response and reliability.  相似文献   

An examination of local similarity theory in the stably stratified boundary layer     

Zbigniew Sorbjan 《Boundary-Layer Meteorology》1987,38(1-2):63-71

A stable boundary layer is investigated in terms of local similarity theory. A study is based on a set of seven runs from the BAO tower (Colorado, U.S.A.). It is shown that a theoretical prediction of constant-with-height similarity functions applies only to ensemble-averaged quantities. Scatter of observational data is analysed.On leave from: Institute of Environmental Engineering, Warsaw Technical University, 00653, Warsaw, Poland.  相似文献   

On the temperature spectrum in the convective boundary layer     

Zbigniew Sorbjan 《Boundary-Layer Meteorology》1989,47(1-4):195-203

A model for the temperature spectrum in the convective boundary layer is presented. The model is developed by using local similarity parameterization of the mixed layer. The model is compared with an idealized temperature spectrum obtained during the Minnesota experiment and exhibits behavior very similar to that observed in the atmosphere.  相似文献   

Local similarity functions derived from second-moment budgets in the convective boundary layer     

Zbigniew Sorbjan 《Boundary-Layer Meteorology》1989,46(1-2):1-11

A further discussion of local similarity in the convective boundary layer is presented. The similarity functions are derived from budget equations for the turbulent heat flux and temperature variance. The obtained similarity curves are compared with atmospheric measurements and with large-eddy simulation results.  相似文献   

Comments on “the velocity spectra in the stable atmospheric boundary layer”     

Zbigniew Sorbjan 《Boundary-Layer Meteorology》1989,48(1-2):203-204

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Wavelet-based multiscale resolution analysis of real and simulated time-series of earthquakes   总被引：1，自引：0，他引：1  

Bogdan Enescu  Kiyoshi Ito  Zbigniew R. Struzik 《Geophysical Journal International》2006,164(1):63-74

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