Multiple Scales of Suspended Sediment Dynamics in a Complex Geometry Estuary

Multiple Scales of Suspended Sediment Dynamics in a Complex Geometry Estuary

Author: Fernanda Minikowski Achete

Publisher: CRC Press

Published: 2020-04-22

Total Pages: 201

ISBN-13: 0429605986

DOWNLOAD EBOOK

Many estuaries are located in urbanized, highly engineered environments. Cohesive sediment plays an important role due to its link with estuarine health and ecology. An important ecological parameter is the suspended sediment concentration (SSC) translated into turbidity levels and sediment budget. This study contributes to investigate and forecast turbidity levels and sediment budget variability at San Francisco Bay-Delta system at a variety of spatial and temporal scales applying a flexible mesh process-based model (Delft3D FM). It is possible to have a robust sediment model, which reproduces 90% of the yearly data derived sediment budget, with simple model settings, like applying one mud fraction and a simple bottom sediment distribution. This finding opens the horizon for modeling less monitored estuaries. Comparing two case studies, i.e. the Sacramento-San Joaquin Delta and Alviso Slough, a classification for estuaries regarding the main sediment dynamic forcing is proposed: event-driven estuary (Delta) and tide-driven estuary (Alviso Slough). In the event-driven estuaries, the rivers are the main sediment source and the tides have minor impact in the net sediment transport. In the tide-driven estuaries, the main sediment source is the bottom sediment and the tide asymmetry defines the net sediment transport. This research also makes advances in connecting different scientific fields and developing a managerial tool to support decision making. It provides the basis to a chain of models, which goes from the hydrodynamics, to suspended sediment, to phytoplankton, to fish, clams and marshes.


Temporal Dynamics of an Estuary: San Francisco Bay

Temporal Dynamics of an Estuary: San Francisco Bay

Author: James E. Cloern

Publisher: Springer

Published: 1985-11-30

Total Pages: 237

ISBN-13: 9061935385

DOWNLOAD EBOOK

Estuaries are highly dynamic systems subject to changes occurring over a spectrum of time scales ranging from very short periods (e. g. over a tidal cycle) to geologic time scales. The nature of an estuary reflects complex responses to many driving forces, each having a characteristic frequency (or frequencies) of change. For example, freshwater inflow to estuaries varies daily in response to short-term events such as storms, seasonally, and between years as a result of longer-term climatic variability. Other important components of weather, e. g. wind speed/ direction and daily insolation, also vary over time scales ranging from hours to years. Tidal amplitude changes continuously with dominant frequencies associated with the semi-diurnal cycle, the fortnightly neap-spring, and the semi-annual cycle. Temporal dynamics of these driving forces evoke responses in the form of changing (I) circulation patterns and mixing, (2) sediment composition and transport, (3) solute speciation and distribution, (4) composition and abundance of particulates, (5) biomass, species composition, and productivity of plant and animal communities, (6) rates of material exchange between the sediments, water column, and atmosphere, and (7) bioavailability of trace metals and other pollutants. The purpose of this book is to examine the temporal dynamics of these properties and processes in the San Francisco Bay estuary.


Estuarine and Coastal Hydrography and Sediment Transport

Estuarine and Coastal Hydrography and Sediment Transport

Author: R. J. Uncles

Publisher: Cambridge University Press

Published: 2017-08-17

Total Pages: 363

ISBN-13: 1107040981

DOWNLOAD EBOOK

A practical guide to the latest techniques to measure sediments, seabed, water and transport mechanisms in estuaries and coastal waters. Covering a broad range of topics, enough background is included to explain how each technology functions. A review of recent fieldwork experiments demonstrates how modern methods apply in real-life scenarios.