Salinity And Tides In Alluvial Estuaries

The book describes an integrated theory that links estuary shape to tidal hydraulics, tidal mixing and salt intrusion. The shape of an alluvial estuary is characterised by exponentially varying width and the absence of bottom slope. This topography is closely related to tidal parameters, hydraulic parameters and parameters that describe 1-dimensional mixing and salt intrusion. Starting from the fundamental equations for conservation of mass and momentum, analytical equations are derived that relate the topography to tidal parameters (tidal excursion, phase lag, tidal damping, tidal amplification), wave celerity, lateral and vertical mixing and salt intrusion. The book presents a review of the state of the art, a comprehensive theoretical background and ample case illustrations from all over the world. It provides tools with which human interference in estuary dynamics can be described and predicted, resulting from, for instance: upstream fresh water abstraction, dredging, climate change or sea-level rise. In describing the interactions between tide, topography, water quality and river discharge, it provides useful information for hydraulic engineers, morphologists, ecologists and people concerned with water quality in alluvial estuaries. Although the book can be used as a text book, it is mainly a monograph aimed at graduate students and researchers. * Provides new integrated theory for tidal hydraulics, tidal mixing and salt intrusion in alluvial estuaries * Presents a consistent set of analytical equations to compute tidal movement, tidal mixing and salt intrusion, derived from the fundamental laws of conservation of mass and momentum * Serves as a practical guide with many illustrations of applications in real estuaries

Multi-channel estuaries, such as the Mekong Delta in Vietnam and the Scheldt in the Netherlands, have characteristics of both the river and the sea, forming a unique environment influenced by tidal movements of the sea and freshwater flow of the river. This study addresses a number of knowledge gaps in multi-channel estuaries by developing a predictive analytical approach for salinity intrusion and discharge estimate in multi-channel estuaries. The new approach agrees well with 1-D hydrodynamic models and observations, indicating its applicability in practice. Most importantly, the study has successfully developed a new theory and a new equation to quantify tidal pumping due to ebb-flood channel residual circulation and the related salt dispersion.

The main objective of this research is to investigate the governing processes and characteristics that drive morphodynamic evolution in alluvial estuaries by application of a process-based numerical model (Delft3D). It is of utmost importance to understand estuarine processes so that impact of human interference (like dredging and land reclamation) and long-term changes (like sea level rise) can be evaluated. The research addresses a number of cases ranging from an rectangular basins to real estuaries like the Western Scheldt in the Netherlands or San Pablo Bay in California. The more schematized approach allow to study morphodynamic evolution over several millennia under constant forcing and answers more fundamental questions related to conditions of equilibrium and related time scales. The more realistic cases give insight into the skill of the approach in predicting decadal morphodynamic developments. More processes are included to mimic realistic conditions and model results are compared to bathymetric measurements over the last century. The research shows that the modeling approach is good capable of describing stable morphodynamic calculations over a timescale of millennia with patterns similar to patterns observed in reality. Additionally, the approach shows that it is possible to predict decadal morphodynamic developments in real estuaries with significant skill.

This book reports the first systematic monitoring and modelling study on water availability, water quality and seawater intrusion of the Shatt al-Arab River (SAR) on the border of Iraq and Iran, where causes and concentration levels of salinity have not yet been fully understood, let alone addressed, leading to conflicting perceptions of its origin (external or internal), the natural conditions and the practices that can explain the current critical conditions. Current scientific knowledge on the SAR salinity problem is deficient, partially due to the complex and dynamic interaction between marine and terrestrial salinity sources, including return flows by water users of the different water sectors in the Euphrates and Tigris rivers upstream of the SAR. The development of a new series of monitoring stations and various modelling approaches helped to better understand the interactions between these different sources. The comprehensive and detailed dataset formed the basis for a validated analytical model that can predict the extent of seawater relative to other salinity sources in an estuary, and for a hydrodynamic model that can predict salinity changes. The adaptability of the models to changing conditions makes them directly applicable by water managers. The procedure can be applied to other comparable systems.

An experimental and analytical study of the basic factors which determine the instantaneous longitudinal distribution of salinity in a partially mixed estuary of constant section is presented. The mass-transfer equation is solved in two parts: (a) the quasi-steady-state convective-diffusion problem for an observer moving with the tidal velocity, and (b) the cyclic translation of saline water due to the tidal velocity. In the steady-state portion the apparent longitudinal diffusion coefficient is a function of the turbulence induced by the tide and of the internal circulations induced by the density difference. An expression is developed for the intrusion length as a function of the estuary length, mean depth, tidal amplitude and period, fresh-water discharge, ocean salinity, and estuary roughness. A stratification number is defined which expresses the degree of stratification or mixing in an estuary. (Author).

This book is a collection of extended papers based on presentations given during the ICEC 2018 conference, held in Caen, France, in August 2018. It explores both the limitations and advantages of current models, and highlights the latest developments concerning new numerical schemes, high-performance computing, multi-physics and multi-scale methods, and better interaction with field or scale model data. Accordingly, it addresses the interests of practitioners, stakeholders, researchers, and engineers active in this field.

Ever-increasing interest in oceanography and marine biology and their relevance to global environmental issues create a demand for authoritative reviews summarizing the results of recent research. Oceanography and Marine Biology: An Annual Review has catered to this demand since its founding by the late Harold Barnes more than 50 years ago. Its objectives are to consider, annually, the basic areas of marine research, returning to them when appropriate in future volumes; to deal with subjects of special and topical importance; and to add new subjects as they arise. The favourable reception and complimentary reviews accorded to all the volumes shows that the series is fulfilling a very real need. Volume 54 follows closely the objectives and style of the earlier volumes, continuing to regard the marine sciences—with all their various aspects—as a unity. Physical, chemical, and biological aspects of marine science are dealt with by experts actively engaged in these fields. The series is an essential reference text for researchers and students in all fields of marine science and related subjects, and it finds a place in libraries of universities, marine laboratories, research institutes and government departments. It is consistently among the highest ranking series in terms of impact factor in the marine biology category of the citation indices compiled by the Institute for Scientific Information/Web of Science.