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Hydrodynamics and Water Quality
The primary reference for the modeling of hydrodynamics and water quality in rivers, lake, estuaries, coastal waters, and wetlands This comprehensive text perfectly illustrates the principles, basic processes, mathematical descriptions, case studies, and practical applications associated with surface waters. It focuses on solving practical problems in rivers, lakes, estuaries, coastal waters, and wetlands. Most of the theories and technical approaches presented within have been implemented in mathematical models and applied to solve practical problems. Throughout the book, case studies are presented to demonstrate how the basic theories and technical approaches are implemented into models, and how these models are applied to solve practical environmental/water resources problems. This new edition of Hydrodynamics and Water Quality: Modeling Rivers, Lakes, and Estuaries has been updated with more than 40% new information. It features several new chapters, including one devoted to shallow water processes in wetlands as well as another focused on extreme value theory and environmental risk analysis. It is also supplemented with a new website that provides files needed for sample applications, such as source codes, executable codes, input files, output files, model manuals, reports, technical notes, and utility programs. This new edition of the book: * Includes more than 120 new/updated figures and 450 references * Covers state-of-the-art hydrodynamics, sediment transport, toxics fate and transport, and water quality in surface waters * Provides essential and updated information on mathematical models * Focuses on how to solve practical problems in surface waters—presenting basic theories and technical approaches so that mathematical models can be understood and applied to simulate processes in surface waters Hailed as \"a great addition to any university library\" by the Journal of the American Water Resources Association (July 2009), Hydrodynamics and Water Quality, Second Edition is an essential reference for practicing engineers, scientists, and water resource managers worldwide.
eBook
A general two-phase debris flow model
This paper presents a new, generalized two‐phase debris flow model that includes many essential physical phenomena. The model employs the Mohr‐Coulomb plasticity for the solid stress, and the fluid stress is modeled as a solid‐volume‐fraction‐gradient‐enhanced non‐Newtonian viscous stress. The generalized interfacial momentum transfer includes viscous drag, buoyancy, and virtual mass. A new, generalized drag force is proposed that covers both solid‐like and fluid‐like contributions, and can be applied to drag ranging from linear to quadratic. Strong coupling between the solid‐ and the fluid‐momentum transfer leads to simultaneous deformation, mixing, and separation of the phases. Inclusion of the non‐Newtonian viscous stresses is important in several aspects. The evolution, advection, and diffusion of the solid‐volume fraction plays an important role. The model, which includes three innovative, fundamentally new, and dominant physical aspects (enhanced viscous stress, virtual mass, generalized drag) constitutes the most generalized two‐phase flow model to date, and can reproduce results from most previous simple models that consider single‐ and two‐phase avalanches and debris flows as special cases. Numerical results indicate that the model can adequately describe the complex dynamics of subaerial two‐phase debris flows, particle‐laden and dispersive flows, sediment transport, and submarine debris flows and associated phenomena.
Key Points
This paper presents a new, generalized and unified two‐phase debris flow model
Includes non‐Newtonian viscous stress, virtual mass, generalized drag, buoyancy
New model adequately describes complex two‐phase debris flow, sediment transport
Journal Article
Estuarine and coastal hydrography and sediment transport
\"A practical guide to the latest remote and in situ techniques used to measure sediments, quantify seabed characteristics, and understand physical properties of water and sediments and transport mechanisms in estuaries and coastal waters. Covering a broad range of topics from global reference frames and bathymetric surveying methods to the use of remote sensing for determining surface-water variables, enough background is included to explain how each technology functions. The advantages and disadvantages of each technology are explained, and a review of recent fieldwork experiments demonstrates how modern methods apply in real-life estuarine and coastal campaigns. Clear explanations of physical processes show links between different disciplines, making the book ideal for students and researchers in the environmental sciences, marine biology, chemistry and geology, whose work relies on an understanding of the physical environment and the way it is changing as a result of climate change, engineering and other influences\"-- Provided by publisher.
Book
Assessment of Annual Sedimentation into Failaka Marina (Kuwait) and Possible Solutions for Reduction of Siltation
AlMashan, N.; Al-Attar, I., and Neelamani, S., 2024. Assessment of annual sedimentation into Failaka Marina (Kuwait) and possible solutions for reduction of siltation.Sedimentation is critical for ports, harbors, and marinas, requiring accurate assessment. Failaka Marina in Kuwait is experiencing a severe noncohesive sedimentation problem. The samples collected at the seven locations along the beach showed that the beach has a uniform grain-size diameter, meaning it is poorly graded sand. The sampling at the tip of the southern breakwater showed that the shoaling is mainly sand. The suspended-sediment concentration varies from 0.025 kg m−3 to 1.2 kg m−3, whereas the mean concentration at the marina entrance is 0.85 kg m−3. The time series of the suspended solids over a year in the seawater surrounding Failaka Island shows a range of 8 to 48,069 ppm. Such a considerable variation in suspended load is due to the massive amounts of dredging and spoil disposal at Boubyan Island and Basra Port (Iraq) when a high sediment load moves around Failaka Island with a concentration of more than 40,000 mg L−1. Annual sedimentation is about 2.35 m y−1, which is responsible for blocking the main entrance for navigation. Kuwait’s Ministry of Communication allocates $4 to $6 million annually for dredging and disposal activities. This study evaluates the six marina entrance modification scenarios to determine the best scenario that achieves a measurable reduction in sedimentation rate in the Marina. Six marina breakwater modifications were studied, and annual sedimentation rates were numerically computed. The study use Coupled MIKE 21/3 to simulate hydrodynamic conditions for cohesive sediment transport in a problem area. Field data from 2015 calibrated and validated the model. The primary sediment-moving force is SE wind and sea-swell waves. Littoral drift along Failaka Island’s southern coastline and high suspended-sediment concentration result in littoral drift and settling. The best scenario showed a 28% sedimentation reduction and a 26% reduction in maintenance dredging costs from the six studied scenarios.
Journal Article
A lower-than-expected saltation threshold at Martian pressure and below
Aeolian sediment transport is observed to occur on Mars as well as other extraterrestrial environments, generating ripples and dunes as on Earth. The search for terrestrial analogs of planetary bedforms, as well as environmental simulation experiments able to reproduce their formation in planetary conditions, are powerful ways to question our understanding of geomorphological processes toward unusual environmental conditions. Here, we perform sediment transport laboratory experiments in a closed-circuit wind tunnel placed in a vacuum chamber and operated at extremely low pressures to show that Martian conditions belong to a previously unexplored saltation regime. The threshold wind speed required to initiate saltation is only quantitatively predicted by state-of-the art models up to a density ratio between grain and air of [Formula: see text] but unexpectedly falls to much lower values for higher density ratios. In contrast, impact ripples, whose emergence is continuously observed on the granular bed over the whole pressure range investigated, display a characteristic wavelength and propagation velocity essentially independent of pressure. A comparison of these findings with existing models suggests that sediment transport at low Reynolds number but high grain-to-fluid density ratio may be dominated by collective effects associated with grain inertia in the granular collisional layer.
Journal Article
Sedimentary crisis at the global scale
Volume 1: \"The Earth's oceans are currently undergoing unprecedented changes: rivers have suffered a severe reduction in their sediment transport, and as a result, sediment input to the oceans has dropped lower than ever before. These inputs have varied over millennia as a result of both natural occurrences and human actions, such as the building of dams and the extraction of materials from riverbeds. Sedimentary Crisis at the Global Scale 1 examines how river basins have been affected by the sedimentary crises of various historical epochs. By studying global balances, it provides insights into the profound disruption of the solid transport of fluvial bodies. The book also explores studies of various rivers, from the Amazon, which remains relatively unaffected, to dying rivers such as the Colorado and the Nile.\" -- Back cover.
Book
Re-evaluating black carbon in the Himalayas and the Tibetan Plateau: concentrations and deposition
Black carbon (BC) is the second most important warming component in the atmosphere after CO2. The BC in the Himalayas and the Tibetan Plateau (HTP) has influenced the Indian monsoon and accelerated the retreat of glaciers, resulting in serious consequences for billions of Asian residents. Although a number of related studies have been conducted in this region, the BC concentrations and deposition rates remain poorly constrained. Because of the presence of arid environments and the potential influence of carbonates in mineral dust (MD), the reported BC concentrations in the HTP are overestimated. In addition, large discrepancies have been reported among the BC deposition derived from lake cores, ice cores, snow pits and models. Therefore, the actual BC concentration and deposition values in this sensitive region must be determined. A comparison between the BC concentrations in acid (HCl)-treated and untreated total suspected particle samples from the HTP showed that the BC concentrations previously reported for the Nam Co station (central part of the HTP) and the Everest station (northern slope of the central Himalayas) were overestimated by approximately 52 ± 35 and 39 ± 24 %, respectively, because of the influence of carbonates in MD. Additionally, the organic carbon (OC) levels were overestimated by approximately 22 ± 10 and 22 ± 12 % for the same reason. Based on previously reported values from the study region, we propose that the actual BC concentrations at the Nam Co and Everest stations are 61 and 154 ng m−3, respectively. Furthermore, a comprehensive comparison of the BC deposition rates obtained via different methods indicated that the deposition of BC in HTP lake cores was mainly related to river sediment transport from the lake basin as a result of climate change (e.g., increases in temperature and precipitation) and that relatively little BC deposition occurred via atmospheric deposition. Therefore, previously reported BC deposition rates from lake cores overestimated the atmospheric deposition of BC in the HTP. Correspondingly, BC deposition derived from snow pits and ice cores agreed well with that derived from models, implying that the BC depositions of these two methods reflect the actual values in the HTP. Therefore, based on reported values from snow pits and ice cores, we propose that the BC deposition in the HTP is 17. 9 ± 5. 3 mg m−2 a−1, with higher and lower values appearing along the fringes and central areas of the HTP, respectively. These adjusted BC concentrations and deposition values in the HTP are critical for performing accurate evaluations of other BC factors, such as atmospheric distribution, radiative forcing and chemical transport in the HTP.
Journal Article