I ; II, Beletrie pro dospělé čtenáře a mládež v češtině., and Obsahuje přívazbu: Obzor Matice slovanské, 188 s. - zde chybí strany s inzercí 31, 32, 63, 64, 79, 80, 95, 96
The recently published new British Flood Estimation Handbook (FEH) is a unique hydrological publication, giving guidance on rainfall and river flood frequency estimation in the United Kingdom. The FEH is an outcome of a five-year research programme at the Centre of Ecology and Hydrology in Wallingford. The FEH provides novel statistical and geostatistical methods and new hydrological approaches used for assessing the rarity of extreme rainfall and flood events. The publication is accompanied by software (WINFAP-FEH) and digital data (FLOOD DATA CD-ROM). The procedures are clearly explained, and supporting theory and examples are included. The FEH clearly deserves the attention of hydrologists around the world. The main objective of this review is to provide our hydrological community with a brief description of the major methodological approaches used in FEH for rainfall and flood frequency analysis. and Nedávno publikovaný nový britský Flood Estimation Handbook predstavuje vo svete jedinečnú hydrologicků príručku podávajúcu ucelený návod - smernicu pre odhad návrhových zrážok a prietokov vo Veľkej Briránii. Toto dielo je výsledkom päťročnej intenzívnej práce tímu odborníkov z Institute of Hydrology vo Wallingforde. Do príručky sú implementované najnovšie metódy matematickej štatistiky a geoštatistiky. Autori v nej tvorivo inovujú a dopĺňajú hlavné metodické postupy používané momentálně vo svete pri odhade N-ročných srážok a prietokov. Celý projekt má aj softverovú podobu. Príručka si zasluhuje oprávnenú pozornosť hydrológov a klimatológov, a preto hlavným cieľom tohto článku je aspoň veľmi stručne oboznámiť našu odbornú verejnosť s týmto významným dielom a priblížiť jej najvýznamnejšie metodické postupy analýzy extrémnych zrážok a prietokov.
This paper presents the results of an experimental and numerical study of a vertical slot fishway (VSF). A 2-D depth-averaged shallow water numerical model PCFLOW2D coupled with three different turbulent models (constant eddy viscosity, Smagorinsky and k - ε) was used. A detailed analysis of numerical parameters needed for a correct simulation of the phenomenon was carried out. Besides the velocity field, attention was paid to important hydraulic parameters such as maximum velocity in the slot region and energy dissipation rate ε in order to evaluate the performance of VSF. A scaled physical hydraulic model was built to ensure reliable experimental data for the validation of the numerical model. Simulations of variant configurations of VSF showed that even small changes in geometry can produce more fishfriendly flow characteristics in pools. The present study indicates that the PCFLOW2D program is an appropriate tool to meet the main demands of the VSF design.
In this paper, two- and three-dimensional numerical modeling is applied in order to simulate water flow behavior over the new Niedów barrage in South Poland. The draining capacity of one of the flood alleviation structures (ogee weir) for exploitation and catastrophic conditions was estimated. In addition, the output of the numerical models is compared with experimental data. The experiments demonstrated that the draining capacity of the barrage alleviation scheme is sufficiently designed for catastrophic scenarios if water is flowing under steady flow conditions. Nevertheless, the new cofferdam, which is part of the temporal reconstruction works, is affecting the draining capacity of the whole low-head barrage project.
The flow of a solid-water mixture through an upward-facing step in a channel is numerically investigated. The effect of expansion ratio, mean solids volume fraction and particle diameter on the velocity field, pressure distribution and solid volume fraction field is studied. Expansion ratios of 0.50 and 0.67, particle diameter of 125 µm and 440 µm and mean solid volume fraction between 0.05 and 0.20 are considered. Particle density is 2465 kg m-3 . An Eulerian twofluid model is used to simulate the flow. Due to the lack of experimental data, the model was validated by comparison to other numerical investigations and to experimental data about the horizontal pipe case. Afterwards, it is studied the effect of the above mentioned parameters upon the degree of coupling between the phases and the extension of the disturbance region in the pressure and solid volume fraction fields downstream the step. Parameters of engineering interest, such as the reattachment length and the pressure recovery downstream the enlargement, are investigated.