Download or read book Modelling Gravel Transport Extraction and Bed Level Change in the Waimakariri River written by Richard Measures and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling Gravel Transport Extraction and Bed Level Change in the Waimakariri River written by Richard Measures and published by . This book was released on 2012 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Resolution Survey and Modelling Techniques to Assess the Sustainability of Gravel Extraction on the Wild Waiapu River East Cape New Zealand written by Danny Baucke and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Waiapu River, located on New Zealand's East Cape, is situated within a highly dynamic landscape with a combination of weak geological substrate, active tectonics and high rates of rainfall. This active setting has been primed for geomorphic change following early 20th century deforestation. Gullying and other mass wasting processes have led to the Waiapu having the highest suspended sediment yields among New Zealand rivers. The river is perceived as aggrading and unstable, but closer examination shows different parts of the river in different states of surplus, stability or deficit. With newly accelerating growth in gravel extraction activity, there is strong interest in establishing background rates of bedlaod transfer in the upper reaches of the Waiapu River. In a survey period from 15th February 2019 to 13th February 2020, four reaches within the upper Waiapu River were examined, with the uppermost and lowermost reaches under gravel extraction operations that are consented to remove a total of 110,000 mÂ3 of gravel annually. Digital Elevation Models (DEM) derived from aerial LiDAR and UAV surveys were used to construct DEMs of Difference (DoD) in order to evaluate changes in morphology induced both by floods and by gravel extraction. While the suspended sediment load for the Waiapu River is well documented, this study looks to assess rates of bedload transfer. For this, the morphological method was used to determine bedload transport rates using the DoDs. To supplement this methodology a 1D, cross-section based model (BedloadWeb) and a 2D morphodynamic model (Delft3D) were used to estimate bedload transport potential for the inter-survey period. Short term morphological changes are found to be directly influenced from extraction pits on the active plain of the river following flood events capable of geomorphic work. These long extraction pits features redirect ow and may induce further lateral erosion. The change model suggests that an average of 34,000 m3 (1700) of material was eroded/deposited from any of the 250-m long discretised cells along the river. By routing the net change within each cell downstream to the next cell, it was found that a strong deficit in the longitudinal gradient emerges at the downstream-most extraction site, suggesting that gravel extraction is in excess of recharge. Modelled bedload transport rates suggest yields of 15,150 m3 (750) and are a reasonable minimum in equilibrium, non-aggrading conditions. Maximum estimates are notably higher (78,000 m3 3900), but such concentrations are not the norm, and represent non-equilibrium hysteresis conditions that might apply at the onset of flooding. The bedload transport rates assessed here via the morphological method are likely to be anomalously low, given that it was an especially dry year for the Waiapu. This helps to emphasise that fluctuations in yield are probably high (+/- 150%, by the modelled estimates) and thus the gravel extraction consenting process should take this into account, perhaps offering a fixed base removal rate, with adjustment to the following year in the event of high flows in the previous year.
Download or read book Gravel bed Rivers V written by M. Paul Mosley and published by . This book was released on 2001 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Resources Management VIII written by C.A. Brebbia and published by WIT Press. This book was released on 2015-06-15 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water Resources Management VIII contains papers presented at the eighth conference in a biennial series organised by the Wessex Institute. First held in 2001, the Conference includes the work of scientists, practitioners and other experts regarding the sustainable management of water resources. It is predicted that population growth and irregular precipitation due to climate change may lead to more restrict ed access to water in certain regions of the world. The problem will be aggravated by human activities that affect the quality of available water. In order to improve strategies for dealing with a scarcity of potable water, it is important to review and compare the performance of current technologies and practices in order to select those that will provide the most effective approaches. It is also important that technologies and practices be able to respond with agility to changing conditions. New ways of thinking are required in order to successfully predict future trends and prepare adequate sustainable solutions. The papers included in this book cover such topics as: Water Management and Planning; Water Rights and Accessibility; Water Markets and Policies; Climate Change; Irrigation; Urban Water Management; Hydraulic Engineering; Water Quality; Pollution Contaminants and Control; River Basin Management; Flood Risk Management; Geo-politics of Water; Water Resources and Economics; Governance and Regulations; Desalination; Water Services.
Download or read book Waimakariri River Bed Level Investigation written by Tony Boyle and published by . This book was released on 2008 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gravel Bed Rivers written by Richard D. Hey and published by . This book was released on 1982 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of papers by an international group of experts that clarifies the physical processes operating in gravel-bed rivers. Identifies engineering and management techniques based on natural flow processes to minimize the effect of river engineering and water resource development on river systems. Promotes improved design and modelling methods. Discusses future research requirements.
Download or read book Gravel Bed Rivers written by Michael Church and published by John Wiley & Sons. This book was released on 2012-02-10 with total page 605 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gravel-Bed Rivers: Processes, Tools, Environments presents a definitive review of current knowledge of gravel-bed rivers, derived from the 7th International Gravel-bed Rivers Workshop, the 5-yearly meeting of the world’s leading authorities in the field. Each chapter in the book has been specifically commissioned to represent areas in which recent progress has been made in the field. The topics covered also represent a coherent progression through the principal areas of the subject (hydraulics; sediment transport; river morphology; tools and methods; applications of science). Definitive review of the current knowledge of gravel-bed rivers Coverage of both fundamental and applied topics Edited by leading academics with contributions from key researchers Thoroughly edited for quality and consistency to provide coherent and logical progression through the principal areas of the subject.
Download or read book Braided Rivers written by Gregory H. Sambrook Smith and published by John Wiley & Sons. This book was released on 2009-03-05 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This important book brings together eighteen cutting-edge researchpapers first presented at the Second International Conference onBraided Rivers. It includes the latest research on the dynamics,deposits and ecology of these rivers. Essential reading for geomorphologists, earth scientists,engineers and ecologists with a pure and applied interest in thestudy, modelling and management of braided rivers.
Download or read book Modeling Sediment Transport Channel Morphology and Gravel Mining in River Bends written by Ilgi Nam and published by . This book was released on 1995 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: A technique is developed and tested to analyze the interaction of flowing water, bed topography, and bedload sediment transport in meandering channels where gravel bars are removed. The method relates the local velocity distribution, bed shear stress and sediment transport conditions to the local bed configuration in river bends before and after gravel bar removal. Specific attention is given to pool-depth changes as an immediate result of gravel removal, the residual effects of boundary shear stress changes, and the potential long-term consequences from subsequent runoff events with brief periods of increased streamflow and sediment transport. The most significant new aspect of this work is the ability to predict whether or not periodic gravel "mining" by means of bar scalping has a residual or cumulative effect on channel morphology and pool depth, particularly in bends. This application is tested against field data collected for the Chetco River and South Santiam River in Oregon, the East Fork River in Wyoming, and the upper Rhone River in France. Some of these sites have been partially subjected to gravel mining; others offer contrasting circumstances to allow comparisons of effects. The study suggests that the maximum velocity distribution shifts inward toward the convex bank of a channel bend at high water levels after gravel removal from a point bar, assuming that sediment transport rates and resupply from upstream are the same as before bar scalping. The inward shift of the maximum velocity distribution causes changes of boundary shear stress distribution in pool zones. Weaker boundary shear stresses are expected in pool zones after bar scalping. This will result in fewer incipient motion events in pool zones over each runoff season. As a result, the pool will experience net sediment deposition as a long-term effect of sediment transport events separated by periods of bed stability.
Download or read book Numerical Simulation of Phenomena Related to Gravel bed Rivers written by Yantao Cui and published by . This book was released on 1996 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Waimakariri River written by Henry Roland Hudson and published by . This book was released on 2005-01-01 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Waimakariri River Bed Sediment Movement for Ecological Resetting written by Maurice John Duncan and published by . This book was released on 2008 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canterbury Regional River Gravel Management Strategy written by Canterbury (N.Z.). Environment Canterbury and published by . This book was released on 2012 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gravel Bed Rivers written by Daizo Tsutsumi and published by John Wiley & Sons. This book was released on 2017-07-05 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Geomorphic Analysis of River Systems written by Kirstie A. Fryirs and published by John Wiley & Sons. This book was released on 2012-09-26 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling a niche in the geomorphology teaching market, this introductory book is built around a 12 week course in fluvial geomorphology. ‘Reading the landscape’ entails making sense of what a riverscape looks like, how it works, how it has evolved over time, and how alterations to one part of a catchment may have secondary consequences elsewhere, over different timeframes. These place-based field analyses are framed within their topographic, climatic and environmental context. Issues and principles presented in the first part of this book provide foundational understandings that underpin the approach to reading the landscape that is presented in the second half of the book. In reading the landscape, detective-style investigations and interpretations are tied to theoretical and conceptual principles to generate catchment-specific analyses of river character, behaviour and evolution, including responses to human disturbance. This book has been constructed as an introductory text on river landscapes, providing a bridge and/or companion to quantitatively-framed or modelled approaches to landscape analysis that are addressed elsewhere. Key principles outlined in the book emphasise the importance of complexity, contingency and emergence in interpreting the character, behaviour and evolution of any given system. The target audience is second and third year undergraduate students in geomorphology, hydrology, earth science and environmental science, as well as river practitioners who use geomorphic understandings to guide scientific and/or management applications. The primary focus of Kirstie and Gary’s research and teaching entails the use of geomorphic principles as a tool with which to develop coherent scientific understandings of river systems, and the application of these understandings in management practice. Kirstie and Gary are co-developers of the River Styles® Framework and Short Course that is widely used in river management, decision-making and training. Additional resources for this book can be found at: www.wiley.com/go/fryirs/riversystems.
Download or read book Landscape and Quaternary Environmental Change in New Zealand written by James Shulmeister and published by Springer. This book was released on 2016-12-16 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together an overview of the recent geological history, active earth and biological processes and human settlement of New Zealand. Topics covered include the very active neotectonic and volcanic setting. Mountain geomorphic processes are examined and new ideas about landsliding are highlighted. The exceptional sedimentary archives of the Whanganui Basin are also presented. As one of two land masses that extend into the southern mid-latitudes, New Zealand is ideally located to investigate changes in Southern Ocean climate. Related to this, mountain glaciation in New Zealand is a focus in global climate change debates. New Zealand also has a unique biota due to its long isolation and is the last major land mass to be settled by people. Advances in DNA technologies have revolutionised our understanding of the histories and processes involved. The book provides a comprehensive review of existing work and highlights new ideas and major debates across all these fields.
