[PDF] Morphological Response Of Sand Bed Streams To Unsteady Flow Events eBook

Author : Etta Haley Gunsolus
Publisher :
Page : 316 pages
File Size : 41,12 MB
Release : 2015
Category :
ISBN :

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Changes in riverine discharge, such as those due to reservoir flushing, seasonal variation or extreme precipitation, can alter sediment transport rates and morphology of the stream bed. Experimental laboratory research investigated the effect of unsteady flow event hydrographs on stream bed morphological response. Laboratory experiments were conducted in a 5.0 mlong sediment transport flume with a bed comprised of a medium sand. Experimental hydrographs were composed of antecedent (base-flow), unsteady event (flood) and post-flood (return to base-flow) stages. Three distinct series of experimental laboratory runs were conducted to systematically investigate the effect of three characteristics of unsteady flow event hydrographs. Series A investigated the effect of the magnitude of the unsteady flow event hydrograph; Series B investigated the effect of the duration of the event; and Series C investigated the effect of the hydrograph shape (i.e., time-to-peak flow). Bed morphological adjustments, sediment transport rates and the composition of the sediment in transport were measured throughout all stages of the experimental runs. Measured values were compared to predicted values calculated using traditional sediment transport and bed form geometry equations assuming steady flow conditions. In general, predicted values greatly underestimated both measured values of sediment transport and bed form geometry. Results show that systematic changes in the magnitude, duration and time-to-peak flow of the unsteady hydrograph cause varying types of hysteresis (clockwise or counter-clockwise) of the sediment transport rates which has a considerable effect on the subsequent bed morphological adjustments. Shorter duration and symmetrical hydrographs exhibit counter-clockwise hysteresis while longer duration and asymmetrical hydrographs exhibit clockwise hysteresis. Results from this thesis have made considerable contributions towards evaluating the effects of unsteady flow event hydrograph characteristics to improve numerical modelling capabilities and accuracies, as well as river and dam management, engineering and restoration.

Author : George Constantinescu
Publisher : CRC Press
Page : 2439 pages
File Size : 29,50 MB
Release : 2016-06-22
Category : Technology & Engineering
ISBN : 1317289129

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Understanding and being able to predict fluvial processes is one of the biggest challenges for hydraulics and environmental engineers, hydrologists and other scientists interested in preserving and restoring the diverse functions of rivers. The interactions among flow, turbulence, vegetation, macroinvertebrates and other organisms, as well as the transport and retention of particulate matter, have important consequences on the ecological health of rivers. Managing rivers in an ecologically friendly way is a major component of sustainable engineering design, maintenance and restoration of ecological habitats. To address these challenges, a major focus of River Flow 2016 was to highlight the latest advances in experimental, computational and theoretical approaches that can be used to deepen our understanding and capacity to predict flow and the associated fluid-driven ecological processes, anthropogenic influences, sediment transport and morphodynamic processes. River Flow 2016 was organized under the auspices of the Committee for Fluvial Hydraulics of the International Association for Hydro-Environment Engineering and Research (IAHR). Since its first edition in 2002, the River Flow conference series has become the main international event focusing on river hydrodynamics, sediment transport, river engineering and restoration. Some of the highlights of the 8th International Conference on Fluvial Hydraulics were to focus on inter-disciplinary research involving, among others, ecological and biological aspects relevant to river flows and processes and to emphasize broader themes dealing with river sustainability. River Flow 2016 contains the contributions presented during the regular sessions covering the main conference themes and the special sessions focusing on specific hot topics of river flow research, and will be of interest to academics interested in hydraulics, hydrology and environmental engineering.

Author : Daizo Tsutsumi
Publisher : John Wiley & Sons
Page : 850 pages
File Size : 13,81 MB
Release : 2017-07-05
Category : Science
ISBN : 111897140X

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With contributions from key researchers across the globe, and edited by internationally recognized leading academics, Gravel-bed Rivers: Processes and Disasters presents the definitive review of current knowledge of gravel-bed rivers. Continuing an established and successful series of scholarly reports, this book consists of the papers presented at the 8th International Gravel-bed Rivers Workshop. Focusing on all the recent progress that has been made in the field, subjects covered include flow, physical modeling, sediment transport theory, techniques and instrumentation, morphodynamics and ecological topics, with special attention given to aspects of disasters relevant to sediment supply and integrated river management. This up-to-date compendium is essential reading for geomorphologists, river engineers and ecologists, river managers, fluvial sedimentologists and advanced students in these fields.

Author : Bruce L. Rhoads
Publisher : Cambridge University Press
Page : 544 pages
File Size : 45,96 MB
Release : 2020-04-29
Category : Science
ISBN : 1108173780

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Rivers are important agents of change that shape the Earth's surface and evolve through time in response to fluctuations in climate and other environmental conditions. They are fundamental in landscape development, and essential for water supply, irrigation, and transportation. This book provides a comprehensive overview of the geomorphological processes that shape rivers and that produce change in the form of rivers. It explores how the dynamics of rivers are being affected by anthropogenic change, including climate change, dam construction, and modification of rivers for flood control and land drainage. It discusses how concern about environmental degradation of rivers has led to the emergence of management strategies to restore and naturalize these systems, and how river management techniques work best when coordinated with the natural dynamics of rivers. This textbook provides an excellent resource for students, researchers, and professionals in fluvial geomorphology, hydrology, river science, and environmental policy.

Author : Pierre Y. Julien
Publisher : Cambridge University Press
Page : 527 pages
File Size : 48,72 MB
Release : 2018-04-12
Category : Science
ISBN : 1107462770

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Completely updated and with three new chapters, this analysis of river dynamics is invaluable for advanced students, researchers and practitioners.

Author : Wim S. J. Uijttewaal
Publisher : CRC Press
Page : 2422 pages
File Size : 41,10 MB
Release : 2020-08-26
Category :
ISBN : 9780367627737

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Rivers form one of the lifelines in our society by providing essential services such as availability of fresh water, navigation, energy, ecosystem services, and flood conveyance. Because of this essential role, mankind has interfered continuously in order to benefit most and at the same time avoid adverse consequences such as flood risk and droughts. This has resulted in often highly engineered rivers with a narrow set of functions. In the last decades rivers are increasingly considered in a more holistic manner as a system with a multitude of interdependent processes. River research and engineering has therefore added to the river fundamentals also themes like ecohydraulics, consequences of climate change, and urbanisation. River Flow 2020 contains the contributions presented at the 10th conference on Fluvial Hydraulics, River Flow 2020, organised under the auspices of the Committee on Fluvial Hydraulics of the International Association for Hydro-Environment Engineering and Research (IAHR). What should have been a lively physical gathering of researchers, students and practitioners, was converted into an online event as the COVID-19 pandemic hindered international travelling and large gatherings of people. Nevertheless, the fluvial hydraulics community showed their interest and to be very much alive with a high number of participations for such event. Since its first edition in 2002, in Louvain-la-Neuve, this series of conferences has found a large and loyal audience in the river research and engineering community while being also attractive to the new researchers and young professionals. This is highlighted by the large number of contributions applying for the Coleman award for young researchers, and also by the number of applications and attendants to the Master Classes which are aimed at young researchers and students. River Flow 2020 aims to provide an updated overview of the ongoing research in this wide range of topics, and contains five major themes which are focus of research in the fluvial environment: river fundamentals, the digital river, the healthy river, extreme events and rivers under pressure. Other highlights of River Flow 2020 include the substantial number of interdisciplinary subthemes and sessions of special interest. The contributions will therefore be of interest to academics in hydraulics, hydrology and environmental engineering as well as practitioners that would like to be updated about the newest findings and hot themes in river research and engineering.

Author : Jiaxing Zhang
Publisher : CRC Press
Page : 2590 pages
File Size : 48,97 MB
Release : 2015-05-06
Category : Computers
ISBN : 1138026743

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This proceedings volume contains selected papers presented at the 2014 International Conference on Informatics, Networking and Intelligent Computing, held in Shenzhen, China. Contributions cover the latest developments and advances in the field of Informatics, Networking and Intelligent Computing.