Tide-Surge Interaction in the Pearl River Estuary: A Case Study of Typhoon Hato (original) (raw)
Related papers
Numerical analysis of effects of tidal variations on storm surges and waves
Applied Ocean Research, 2008
This study examines the effects of tides on surges, wave setups and waves, in terms of tidal amplitudes and phases, by using a coupled numerical model of Surge, WAve and Tide (called as SuWAT). The SuWAT model, composed of depth integrated nonlinear shallow water equations and Simulating WAves Nearshore (SWAN) model, is able to simultaneously run with an arbitrary number of nested domains by using the Message Passing Interface. The results for an idealized case indicate that surge and wave setup are increased in the phase of low water and decreased in the high water phase; on the other hand, waves change in a reverse manner. Such changes are enhanced by large tidal variations. The conventional method (e.g., surge plus tide independently) has the possibility of overestimation for the total water level. The hindcast results for Typhoon Ewiniar in 2006 show that the run with tides is more accurate 10% than that without tides in coastal areas of Korea. The nested scheme improves the accuracy up to 40% for the prediction of water levels in the simulations. It is shown that the present coupled model, SuWAT, is capable of predicting both water levels and waves under storm events with reasonable accuracy against the observations.
A Numerical Model of Tides and Typhoon Surges around Taiwan
In this study we developed a two-dimensional numerical model to predict tide and typhoon surge around Taiwan. The storm surge associating with a typhoon approaching to Taiwan is one of the main causes that floods frequently occur in the low land areas in certain exposed coastlines. The finite difference method is used to solve the control equations. The model area is 900 km× 900 km, and Taiwan lies in the central part of model. The tides at open boundaries of model are the driving forces for tidal flow inside the model. The tides at model boundaries are calculated through harmonic method making use of the principal tidal constants of M2, S2, K1 and O1 partial tides. Air pressure gradient and wind stress are considered as the
Estuaries and Coasts, 2020
The Río de la Plata estuary (RdP) is characterized by the large flow of its tributary rivers (Q), with an average of 22,000 m 3 s −1 and an interannual variability range from 8000 to 90,000 m 3 s −1. In this work, the hypothesis that the current due to that flow (CDR) interacts nonlinearly with both the tides and storm surges is evaluated utilizing water level observations and numerical simulations. Two tide gauge time series gathered at the freshwater tidal zone (FTZ) of the RdP are analyzed with the novel surrogate analysis. The analysis is applied for periods of high, medium and low Q. Results show that both interactions occur at the upper half of the FTZ and increase with Q. Harmonic analyses support the surrogate analysis' conclusions and show that tide-CDR interaction redistributes the energy among tidal harmonics, increasing asymmetry. Numerical simulations confirm that (i) both interactions maximize at the upper half of the FTZ and decrease downstream; and (ii) they are modulated by Q; a rise of about 14,000 m 3 s −1 (interquartile range) can produce an intensification of 50% and 100% of the amplitudes of the tide-CDR and surge-CDR interactions, respectively; and (iii) both interactions introduce asymmetries in the water level, with faster rises and slower falls; (iv) the quadratic bottom friction is the main source of both interactions; (v) tide-CDR interaction represents 12% of the water level associated with the tide, whereas surge-CDR interaction accounts for 5% of the surge peak; and (vi) the interactions are significant in the upper FTZ because there, the magnitude of the currents associated with the tide and the surge are comparable to CDR; downstream, the channel widens and CDR decreases. Keywords Tide-river flow interaction • Surge-river flow interaction • Río de la Plata estuary • Storm surge modeling • Storm surge forecast Communicated by Arnoldo Valle-Levinson Matías G. Dinápoli
Journal of Geophysical Research, 2010
This study applied the finite volume coastal ocean model (FVCOM) to the storm surge induced by Hurricane Rita along the Louisiana-Texas coast. The model was calibrated for tides and validated with observed water levels. Peak water levels were shown to be lower than expected for a landfall at high tide. For low-and high-tide landfalls, nonlinear effects due to tide-surge coupling were constructive and destructive to total storm tide, respectively, and their magnitude reached up to 70% of the tidal amplitude in the Rita application. Tide-surge interaction was further examined using a standard hurricane under idealized scenarios to evaluate the effects of various shelf geometries, tides, and landfall timings (relative to tide). Nonlinearity was important between landfall position and locations within 2.5 × radius of maximum winds. On an idealized wide continental shelf, nonlinear effects reached up to 80% of the tidal amplitude with an S2 tide and up to 47% with a K1 tide. Increasing average depths by 4 m reduced nonlinear effects to 41% of the tidal amplitude; increasing the slope by a factor of 3 produced nonlinearities of just 26% of tide (both with a K1 tide). The nonlinear effect was greatest for landfalls at low tide, followed by landfalls at high tide and then by landfalls at midebb or midflood.
Simulating a typhoon storm surge in the East Sea of China using a coupled model
Progress in Natural Science, 2009
A coupled numerical model with a 2 0 Â 2 0 resolution grid has been developed and used to simulate five typical typhoon storm surges (5612, 7413, 7910, 8114, and 9711) in the East Sea of China. Three main driving forces have been considered in this coupled model: wave radiation stress, combined wave-current bottom shear stress and wave-state-dependent surface wind stress. This model has then been compared with in situ measurements of the storm setup. The effect of different driving force components on the total storm surge has also been investigated. This study has found that the coupled model with high resolution is capable of simulating the five typical typhoons better than the uncoupled models, and that the wave-dependent surface wind stress plays an important role in typhoon storm surge-wave coupling in this area and can increase the storm setup by 1 m. The study of the five typhoon cases has shown that the general coupling effects could increase storm setup by 20-32%. Thus, it is suggested that to predict typhoon storm surges in the East Sea of China, a storm surge-wave coupled model be adopted.
Geosciences
In this study, monsoon-induced surge during high tides at the Southeast coast of Vietnam was analyzed based on the observed tide data at the Vung Tau station in the period between 1997—2016. Specifically, the surge was determined by removing the astronomical tide from the observed total water level. The two-dimensional Regional Ocean Model System (ROMS 2D) was applied to simulate the surge induced by monsoons during spring tide. The surge observations showed that the change of peak surge did not follow a clear trend, of either an increase or decrease, over time. A peak surge of over 40 cm appeared mainly in October and November, although the peak of the astronomical tide was higher in December. ROMS 2D was validated with the observational data, and the model could sufficiently reproduce the wind-induced surge during high tides. This study therefor ere commends for ROMS 2D to be used in operational forecasts in this area.
An Efficient Tide-Surge Interaction Model for the Coast of Bangladesh
China Ocean Engineering, 2020
The numerical method of lines (MOLs) in coordination with the classical fourth-order Runge-Kutta (RK(4, 4)) method is used to solve shallow water equations (SWEs) for foreseeing water levels owing to the nonlinear interaction of tide and surge accompanying with a storm along the coast of Bangladesh. The SWEs are developed by extending the body forces with tide generating forces (TGFs). Spatial variables of the SWEs along with the boundary conditions are approximated by means of finite difference technique on an Arakawa C-grid to attain a system of ordinary differential equations (ODEs) of initial valued in time, which are being solved with the aid of the RK(4, 4) method. Nested grid technique is adopted to solve coastal complexities closely with least computational cost. A stable tidal solution in the region of our choice is produced by applying the tidal forcing with the major tidal constituent M 2 (lunar semi-diurnal) along the southern open-sea boundary of the outer scheme. Numerical experimentations are carried out to simulate water levels generated by the cyclonic storm AILA along the coast of Bangladesh. The model simulated results are found to be in a reasonable agreement with the limited available reported data and observations.
Coastal Engineering Proceedings, 2012
The present study focuses on the risks of storm surge caused by future increases in typhoon intensity due to climate change. These risks were analyzed by integrating weather, wave, storm surge and tide prediction systems into a new simulation methodology. This model, which the authors developed by themselves, makes it possible to calculate the weather fields of typhoons in the past as well as in the future on the basis of meteorology and can simulate waves in a complex geographical area, in contrast with many previous storm surge simulation methods which were not based on accurate meteorological models. The model was verified to accurately reproduce historical typhoons and waves and thus is a useful tool for the analysis of future climate risks.
This dissertation presents the development of a two-dimensional St. Johns River model and the coupling of hydrodynamic and wave models for the simulation of storm tides. The hydrodynamic model employed for calculating tides and surges is ADCIRC-2DDI (ADvanced CIRCulation Model for Shelves, Coasts and Estuaries, Two-Dimensional Depth Integrated) developed by Luettich et al. (1992). The finite element based model solves the fully nonlinear shallow water equations in the generalized wave continuity form. Hydrodynamic applications are operated with the following forcings: 1) astronomical tides, 2) inflows from tributaries, 3) meteorological effects (winds and pressure), and 4) waves (wind-induced waves). The wave model applied for wind-induced wave simulation is the third-generation SWAN (Simulating WAves Nearshore), applicable to the estimation of wave parameters in coastal areas and estuaries. The SWAN model is governed by the wave action balance equation driven by wind, sea surface e...