scholarly journals The role of river discharge and geometric structure on diurnal tidal dynamics, Alabama, USA

2021 ◽  
Author(s):  
Steven Louis Dykstra ◽  
Brian Dzwonkowski ◽  
Raymond Torres
Keyword(s):  
Geometric Structure ◽  
River Discharge ◽  
Tidal Dynamics

scholarly journals Seasonal Tidal Dynamics in the Qiantang Estuary: The Importance of Morphological Evolution

2021 ◽  
Vol 9 ◽  
Author(s):  
Dongfeng Xie ◽  
Zheng Bing Wang
Keyword(s):  
River Discharge ◽  
Morphological Changes ◽  
Morphological Evolution ◽  
Sediment Accumulation ◽  
Water Levels ◽  
Tidal Range ◽  
Tidal Dynamics ◽  
Bathymetric Data ◽  
Bed Erosion

Despite the increasing number of studies on the river-tide interactions in estuaries, less attention has been paid to the role of seasonal morphological changes on tidal regime. This study analyzes the seasonal interplay of river and tide in the Qiantang Estuary, China, particularly focusing on the influences of the active morphological evolution induced by the seasonal variation of river discharge. The study is based on the high and low water levels at three representative stations along the estuary and daily river discharge through 2015, an intermediate flow year in which a typical river flood occurred, as well as the bathymetric data measured in April, July and November, 2015. The results show strong seasonal variations of the water level in addition to the spring-neap variation. These variations are obviously due to the interaction between river discharge and tide but can only be fully explained by including the effect of morphological changes. Two types of the influences of the variation of the river discharge on the tidal dynamics in the estuary can be distinguished: one is immediately induced by the high flow and the other continues for a much longer period because of the bed erosion and the following bed recovery. Tidal range in the upper reach can be doubled after the flood because of bed erosion and then decrease under normal discharge periods due to sediment accumulation. Over a relatively short term such as a month or a spring-neap tidal cycle, there exist good relationships between the tidal range, tidal amplification in the upper reach and the tidal range at the mouth, and between the hydraulic head over the upper and lower reaches. Such relationships are unclear if all data over the whole year are considered together, mainly because of the active morphological evolution.

The role of tides, river discharge and wind on the residual circulation of Maputo Bay

2020 ◽  
pp. 101604
Author(s):  
Paulo J. Sigaúque ◽  
Carlos A.F. Schettini ◽  
Samuel S. Valentim ◽  
Eduardo Siegle
Keyword(s):  
River Discharge ◽  
Residual Circulation

scholarly journals A Study on Role of Fluctuation in River Discharge in Forming River Environment

1998 ◽  
Vol 26 ◽  
pp. 77-84
Author(s):  
Minoru YASUDA ◽  
Yasuo SHIMIZU ◽  
Takayuki TAKEMOTO
Keyword(s):  
River Discharge

scholarly journals Time Evolution of Estuarine Turbidity Maxima in Well-Mixed, Tidally Dominated Estuaries: The Role of Availability- and Erosion-Limited Conditions

2018 ◽  
Vol 48 (8) ◽  
pp. 1629-1650 ◽  
Author(s):  
Ronald L. Brouwer ◽  
George P. Schramkowski ◽  
Yoeri M. Dijkstra ◽  
Henk M. Schuttelaars
Keyword(s):  
River Discharge ◽  
Suspended Sediment Concentration ◽  
Time Lag ◽  
Sediment Concentration ◽  
Fine Sediment ◽  
Time Varying ◽  
Hydrodynamic Conditions ◽  
Good Qualitative Agreement ◽  
Estuarine Turbidity Maxima

AbstractUsing an idealized width-averaged process-based model, the role of a mud pool on the bed and time-varying river discharge on the trapping of fine sediment is systematically investigated. For this purpose, a dynamically and physically motivated description of erodibility is presented, which relates the amount of sediment on the bed to the suspended sediment concentration (SSC). We can distinguish between two states: in the availability-limited state, the SSC is limited by the amount of erodible sediment at the bed. Over time, under constant forcing conditions, the estuary evolves to morphodynamic equilibrium. In the erosion-limited state, there is an abundant amount of sediment at the bed so that sediment pickup occurs at the maximum possible rate. The SSC is then limited by the local hydrodynamic conditions. In this state, the estuary keeps importing sediment, forming an erodible bottom pool that grows in time. These two states can be used to explain the response of an estuary to changing river discharge. Under availability-limited conditions, periods of high river discharge push estuarine turbidity maxima (ETMs) downstream, while drier periods allow ETMs to move upstream. However, when the estuary is in an erosion-limited state during low river discharge, a bottom pool is formed. When the discharge then increases, it takes time to deplete this pool, so that an ETM located over a bottom pool moves with a significant time lag relative to changes in the river discharge. Good qualitative agreement is found between model results and observations in the Scheldt Estuary of surface SSC using a representative year of discharge conditions.

A seasonal tropical sink for atmospheric CO2 in the Atlantic ocean: the role of the Amazon River discharge

2000 ◽  
Vol 68 (3) ◽  
pp. 183-201 ◽  
Author(s):  
J.F Ternon ◽  
C Oudot ◽  
A Dessier ◽  
D Diverres
Keyword(s):  
Atlantic Ocean ◽  
River Discharge ◽  
Atmospheric Co2 ◽  
Amazon River

Riemannian and Euclidean material structures in anelasticity

2020 ◽  
Vol 25 (6) ◽  
pp. 1267-1293 ◽  
Author(s):  
Fabio Sozio ◽  
Arash Yavari
Keyword(s):  
Geometric Structure ◽  
Deformation Gradient ◽  
Linear Momentum ◽  
The Other ◽  
Governing Equations ◽  
Multiplicative Decomposition ◽  
Material Forces ◽  
Geometric Structures ◽  
Non Linear

In this paper, we discuss the mechanics of anelastic bodies with respect to a Riemannian and a Euclidean geometric structure on the material manifold. These two structures provide two equivalent sets of governing equations that correspond to the geometrical and classical approaches to non-linear anelasticity. This paper provides a parallelism between the two approaches and explains how to go from one to the other. We work in the setting of the multiplicative decomposition of deformation gradient seen as a non-holonomic change of frame in the material manifold. This allows one to define, in addition to the two geometric structures, a Weitzenböck connection on the material manifold. We use this connection to express natural uniformity in a geometrically meaningful way. The concept of uniformity is then extended to the Riemannian and Euclidean structures. Finally, we discuss the role of non-uniformity in the form of material forces that appear in the configurational form of the balance of linear momentum with respect to the two structures.

Extreme nonhydrostatic tidal dynamics

2019 ◽  
pp. 37-51
Author(s):  
Наум Евсеевич Вольцингер ◽  
Алексей Анатольевич Андросов
Keyword(s):  
Boundary Value Problem ◽  
Large Scale ◽  
Water Exchange ◽  
Dynamic Pressure ◽  
Boundary Value ◽  
Vertical Motion ◽  
Vertical Acceleration ◽  
Tidal Dynamics ◽  
The Pacific

Моделирование длинноволновых океанологических процессов традиционно выполняется в гидростатическом (Гс) приближении, обеспечивающем высокую точность расчета гидрофизических полей, когда вертикальным ускорением движения можно пренебречь. На горном рельефе это не так, и учет динамической компоненты давления становится необходимым. Негидростатическое (Нг) моделирование крупномасштабных океанологических явлений реализуется решением 3D краевой гидродинамической задачи. Структуру метода составляют этапы решения Гс-задачи, краевой задачи для уравнения Пуассона (Нг) и коррекции полей гидрофизических характеристик. Значимость Нг-фактора выявляется при рассмотрении безразмерного вида уравнений, когда безразмерные параметры характеризуют горный рельеф области. Случай резких изменений рельефа, требующий решения Нг-задачи, - пролив Ломбок. Приводятся оценки Нг-фактора в водообмене между океанами, результаты сравнения спектров вертикальной скорости в Гс- и Нг-постановках. Modelling of long-wave oceanological processes is traditionally performed in a hydrostatic (Hs) approximation, which ensures high accuracy of the calculation of hydrophysical fields, when the vertical acceleration of vertical motion can be neglected. In mountainous terrain, this is not the case, and consideration of the dynamic pressure component becomes necessary. Non-hydrostatic (Nh) modelling of large-scale oceanological phenomena is implemented by solving hydrodynamic boundary value problem in an arbitrary 3D domain. The structure of the method consists of the stages of solving the Hs problem, the boundary value problem for the Poisson equation (Nh), and the correction of the fields of hydrophysical characteristics. That is the pressure is presented as a sum of its hydrostatic and dynamical components. Significance of Nh is revealed when considering the dimensionless type of equations, when dimensionless parameters characterize the mountain relief of the region. The Lombok Strait having a complex morphometric structure is an important link in the water exchange between the Pacific and Indian Oceans, it has been chosen as the object for modelling. Estimates of the role of Nh in water exchange between the oceans are given using the comparison of the solution for problems in Hs and Nh sets. It indicates the need to take into account Nh in conditions of pronounced sea mountain relief.

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