Chilwoo Lee

Jung-A Yang

Yongsu Na

Byoungjoon Na

Sooncheol Hwang

Junsu Noh

Jihyeon Yoon

Asrini Chrysanti

The Coastal Hydrodynamics Lab at KU focuses on understanding coastal hydrodynamic processes, coastal hazards, and environmental impacts. The lab employs numerical modeling, laboratory experiments, and field observations to study wave and tidal phenomena and provide solutions for coastal environment challenges.

캔자스대학교 연안 수역학 연구실은 연안 수역학적 과정, 연안 재해 및 환경 영향에 대한 이해에 중점을 둔다. 파도 및 조석 현상을 연구하고 연안 환경 문제에 대한 해결책을 제공하기 위해 수치 모델링, 실험실 실험 및 현장 관측을 활용한다.

A Second-order Well-balanced Reconstruction for the Shallow Flows with Wet/dry Fronts

An Interactive Nearshore Wave Simulator for Rapid Design Prototyping and Natural Hazard Education

A random forest-based method for reconstructing pressure fields in tropical cyclones from wind data

Topocaustically Driven Similarity in Long-Distance Tsunami Runup Along a Coast

Unraveling Atmosphere and Surface Boundary Interactions Behind Extreme Tropical Rainfall: A Case Study in Indonesia Using Fully Coupled Atmosphere-Hydrology Simulations

A GPU-accelerated Numerical Model for Nearshore Scalar Transport by Dispersive Shallow Water Flows

Understanding Tidal Jet Vortices Over Complex Bathymetry via Numerical Modeling and Drone Observation: Match and Mismatch in the Vortex Dynamics Under Idealized and Realistic Topographic Settings

A Study on Key Determinants in Enhancing Storm Surges along the Coast: Interplay between Tropical Cyclone Motion and Coastal Geometry

An efficient HLL-based scheme for capturing contact-discontinuity in scalar transport by shallow water flow

Statistical Analysis of the Tsunamis from Multiple Faults' Sequential Failure with Different Time-Intervals and Geographical Layouts

Near Real-time Predictions of Tropical Cyclone Trajectory and Intensity in the Northwestern Pacific Ocean using Echo State Network

Probabilistic Assessment of Delayed Multi-Fault Rupture Effect on Maximum Tsunami Runup along the East Coast of Korea

Void fraction estimation using a simple combined wave gauge system under breaking waves

Adaptive Third Order Adams-Bashforth Time Integration for Extended Boussinesq Equations

Prediction of Atmospheric Motion Vectors around Typhoons using Generative Adversarial Network

Modeling of Accidental Oil Spill at the Different Phases of LNG Terminal Construction

An Analytical and Numerical Study of a Vertically Discretized Multi-paddle Wavemaker for Generating Free Surface and Internal Waves

Active Tsunami Generation by Tectonic Seafloor Deformations of Arbitrary Geometry Considering Rupture Kinematics

Quantitative Assessment of Inundation Risks from Physical Contributors Associated with Future Storm Surges: A Case Study of Typhoon Maemi (2003)

Assessment of Uncertainties in Projecting Future Changes to Extreme Storm Surge Height Depending of Future SST and Greenhouse Gas Concentration Scenarios

Field Survey and Numerical Modelling of the December 22, 2018 Anak Krakatau Tsunami

The Effect of Nozzle Geometry on the Turbulence Evolution in an Axisymmetric Jet Flow: a Focus on Fractals

Modeling Scour and Deposition in Harbors due to Complex Tsunami-Induced Currents

Three-dimensional Hydrodynamics Associated with a Solitary Wave Traveling over an Alongshore-variable, Shallow Shelf

Comparative Study on the Numerical Simulation of Bathymetric Changes under Storm Condition

Role of Shelf Geometry and Wave Breaking in Single N-type Tsunami Runup under Geophysical-Scale

Increasing Flood Risk due to River Runoff in the Estuarine Area during a Storm Landfall

Lagrangian-like Volume Tracking Paradigm for Mass, Momentum, and Energy of Nearshore Tsunamis and Damping Mechanism

Observations and modeling of tsunami-induced currents in ports and harbors

Assessment of the tsunami‐induced current hazard

Nested and multi-physics modeling of tsunami evolution from generation to inundation

Field survey and numerical modelling of the December 22, 2018 Anak Krakatau tsunami

Increasing flood risk due to river runoff in the estuarine area during a storm landfall

Coastal impacts of the March 11th Tohoku, Japan tsunami in the Galapagos Islands

Interaction of dispersive water waves with weakly sheared currents of arbitrary profile

Experimental study of solitary wave evolution over a 3D shallow shelf

Calculation of irregular wave reflection from perforated-wall caisson breakwaters using a regular wave model

Assessment of uncertainties in projecting future changes to extreme storm surge height depending on future SST and greenhouse gas concentration scenarios

Performance comparison of spectral wave models based on different governing equations including wave breaking

Near real-time predictions of tropical cyclone trajectory and intensity in the northwestern Pacific Ocean using echo state network

Active tsunami generation by tectonic seafloor deformations of arbitrary geometry considering rupture kinematics

Three-dimensional hydrodynamics associated with a solitary wave traveling over an alongshore variable shallow shelf

Adaptive third order Adams-Bashforth time integration for extended Boussinesq equations

Prediction of atmospheric motion vectors around typhoons using generative adversarial network

Quantitative assessment of inundation risks from physical contributors associated with future storm surges: a case study of Typhoon Maemi (2003)

Role of shelf geometry and wave breaking in single N-type tsunami runup under geophysical-scale

A study on key determinants in enhancing storm surges along the coast: Interplay between tropical cyclone motion and coastal geometry

An analytical and numerical study of a vertically discretized multi-paddle wavemaker for generating free surface and internal waves

Patrick Lynett

Jose C. Borrero

DAEHONG KIM

Do Kideok

Robert Weiss

Willington Renteria

Kyung-Duck Suh

Hajime Mase

Nobuhito Mori

Dougal Greer

Costas Synolakis

Hermann M. Fritz

August Daulat

Dini Purbani

Dinar Catur Istiyanto

ADNAN PRASETYA

Scott Socolofsky

Sangyoung Son

Tsunamis, or “harbor waves” in Japanese, are so-named due to common observations of enhanced wave heights, currents and damage in harbors and ports. However, dynamic currents induced by these waves, while regularly observed and known to cause significant damage, are poorly understood. Observations and modeling of the currents induced by the 2011 Tohoku and 2004 Indian Ocean tsunamis allows us to show that the strongest flows in harbor basins are governed by horizontally sheared and rotational shallow features, such as jets and large eddies. When examining currents in harbors, this conclusion will generally require a simulation approach that both includes the relevant physical processes in the governing equations and uses a numerical scheme that does not artificially damp these features. Without proper representation of the physics associated with these phenomena, predictive models may …

The occurrence of tsunami damage is not limited to events causing coastal inundation. Even without flooding, maritime assets are vulnerable to significant damage from strong currents and associated drag forces. While such impacts have been observed in the past, they have not been well studied in any context. Nearshore tsunami currents are governed by nonlinear and turbulent physics and often have large spatial and temporal variability making high‐fidelity modeling particularly challenging. Furthermore, measured data for the validation of numerical simulations is limited, with few quality data sets appearing after recent tsunami events. In this paper, we present a systematic approach for the interpretation of measured tsunami‐induced current impacts as well as a validation approach for simulation tools. The methods and results provided here lay the foundation for much needed efforts to assess tsunami hazards …

This paper aims to introduce non-dispersive shallow water and dispersive, Boussinesq-type numerical models used in tsunami modeling, as well as an approach to two-way couple these models together. The fundamental purpose of the coupling effort is to develop the capability to seamlessly model tsunami evolution from generation to inundation with fine scale resolution, without the loss of locally important physics. The two model components are briefly introduced, and the physical mismatch between the two models is examined analytically. As coupling of numerically and physically heterogeneous models may result in undesirable errors, a general benchmark test has been undertaken to provide a parameter range for expected accuracy and stability. Long wave propagation onto a shallow shelf is simulated to validate the coupled model, examining the importance of dispersive and nonlinear effects in the …

On December 22, 2018, the eruption and flank collapse of the Anak Krakatau volcano generated a tsunami in the Sunda Strait causing catastrophic damage to uninhabited coastlines proximal to the source. Along the heavily populated shores of Banten and Lampung provinces in Java and Sumatra, tsunami waves caused severe damage, extensive inundation and more than 430 deaths. An international tsunami survey team (ITST) deployed 6 weeks after the event documented the tsunami effects including runup heights, flow depths and inundation distances, as well as sediment deposition patterns and impacts on infrastructure and the natural environment. The team also interviewed numerous eyewitnesses and educated residents about tsunami hazards. This ITST was the first to visit and document the extreme tsunami effects on the small islands in the Sunda Strait closest to Anak Krakatau (Rakata, Panjang …

Unlike inundation from a tsunami, inundation originating from a tropical cyclone is rather complex since it is usually accompanied by torrential rain. Runoff in the vicinity of an estuarine outlet may thus incur additional inundation damage. In this study, a modeling system is proposed that considers the river discharge effect in addition to tides and surges to enhance the modeling accuracy of storm-induced inundation in coastal areas. The hydrodynamic model (Delft3D) and hydrological model (HEC-HMS) were coupled to account for all the flooding drivers, such as tides, storm surges, river discharges, and their interactions. In the coupled model, Delft3D was responsible for tidal and storm-induced surging motions, while HEC-HMS was used to calculate the river discharge at the downstream outlet of basins. Typhoon Maemi, which caused severe inundation damage to the Korean peninsula in 2003, was simulated by …

On March 11, 2011 at 5:46:23 UTC (March 10 11:46:23 PM Galapagos Local Time), the M w 9.0 Great East Japan Earthquake occurred near the Tohoku region off the east coast of Japan, spawning a Pacific-wide tsunami. Approximately 12,000 km away, the Galapagos Islands experienced moderate tsunami impacts, including flooding, structural damage, and strong currents. In this paper, we present observations and measurements of the tsunami effects in the Galapagos, focusing on the four largest islands in the archipelago; (from west to east) Isabela, Santiagio, Santa Cruz, and San Cristobal. Access to the tsunami affected areas was one of the largest challenges of the field survey. Aside from approximately ten sandy beaches open to tourists, all other shoreline locations are restricted to anyone without a research permit; open cooperation with the Galapagos National Park provided the survey team complete …

A set of depth-integrated equations describing combined wave–current flows is derived and validated. To account for the effect of turbulence induced by interactions between waves and currents with arbitrary horizontal vorticity, new additional stress terms are introduced. These stresses are functions of a parameter b that relates the relative importance of wave radiation stress and bottom friction stress to the wave–current interaction. To solve the equations, a fourth-order MUSCL-TVD scheme with an approximate Riemann solver is adopted. As a first-order check of the model, the Doppler shift effect and wave dispersion over linearly sheared currents are analytically shown to be retained appropriately in the equation set. The model results are then validated through comparisons with three experimental data sets. First, based on the experiments of Kemp and Simons (1982, 1983), a reasonable functional form of b is …

A laboratory experiment was performed to investigate the three-dimensional turbulence and kinematic properties that develop due to a breaking solitary propagating over an irregular shallow water bathymetry. The bathymetry consisted of a deep water region connected to a shallow shelf via a relatively steep slope. The offshore boundary of the shelf break varied in the longshore direction, such that the shelf had a triangular shape in plan view, with the widest part of the shelf along the basin centerline. Free surface elevations and fluid velocities were measured using wave gauges and three-dimensional acoustic-Doppler velocimeters (ADVs), respectively. From the free surface elevations the evolution and runup of the wave was revealed; while from the ADVs, the velocity and turbulent energy was determined and specific turbulent events and coherent structures were identified. It was found that significant shoaling was confined to areas with gentler sloping bathymetry near the basin side walls and the runup varied weakly in the alongshore direction. The runup was characterized by a refraction-generated jetting mechanism caused by the convergence of water mass near the basin centerline. The jetting mechanism caused the greatest cross-shore velocities to be located near the basin centerline. The greatest turbulent events were well correlated to borefronts, of which there were four, caused by the leading wave, beach reflections, and shelf-trapped oscillations. Along the shelf break, a large, shallow-water eddy developed which was found to have a peculiar three-dimensional flow field, where maximum velocity components were found at mid …

In this paper, we examine several methods for calculating the reflection of irregular waves from a perforated-wall caisson breakwater using a regular wave model. The first method is the traditional regular wave approximation, which approximates the irregular waves as a single regular wave whose height and period are the root-mean-squared wave height and significant wave period, respectively. The second is to use the regular wave model, repeatedly, for each frequency component of the irregular wave spectrum. The wave period is determined as the reciprocal of the frequency, and the root-mean-squared wave height is used for all the frequencies. The third method is the same as the second one, but the wave height corresponding to the energy of each component wave is used. Comparison with experimental data of previous authors shows the second method is the most adequate, giving reasonable …

We assess uncertainties in projecting future changes in extreme storm surge height (SSH) based on typhoon data extracted from ensemble experiment results with four sea surface temperature (SST) conditions and three global warming scenarios using a single atmospheric global climate model. In particular, this study focus on typhoons passing around the Korean Peninsula (KP) defined as the region of 32 to 40° N and 122 to 132° E. It is predicted the number of the typhoons affecting the KP will decrease by 4~73% while their strength will increase by 0.8~1.4% under the given future conditions. The locations of genesis and lysis of the typhoons are expected to be shifted towards the northwest and northeast for all ensemble experiment conditions, respectively. However, the extent of their change varies depending on the future SST and global warming conditions. Storm surge simulations were carried out by using …

The performance of three spectral wave models based on different types of governing equations, REF/DIF S, MIKE 21 BW module, and SWAN, was compared by using four laboratory or field experimental data sets. The comparison was focused on accurate prediction of measured wave heights. Characteristics of the three wave models were discussed and their overall predictability of the measured data was evaluated by calculating mean absolute relative errors of wave height. All the numerical models simulated fairly well shoaling and breaking of waves propagating on a plane sloping beach, but the model accuracy was somewhat degenerated in simulating waves propagating over a barred beach. Among the three models, MIKE 21 BW was the most insensitive to the bathymetric change. Combined refraction-diffraction over a shoal without breaking was quite well simulated by the models, especially by REF/DIF S …

A recurrent neural network model for predicting the trajectories and intensities of tropical cyclones (TCs) in the northwestern Pacific Ocean basin is described in the present study. By training an echo state network with a meteorological dataset, the recurrent neural network model, named Reservoir Computing for Tropical Cyclone Prediction (RCTCP) was developed to predict four attributes of TCs, i.e., latitude, longitude, maximum sustained wind speed, and minimum sea level pressure. To comprise the dataset, best track data of the TCs occurred in the basin from 1945 to 2017 were obtained from the U.S. Joint Typhoon Warning Center. The CERA-20C and ERA-Interim reanalysis datasets were used along with dynamic time warping to compensate for the unreported pressure information in the best track data. The data for each TC were then attached end-to-end based on the order of occurrence to form a single …

In this study, the propagation of surface water waves initially displaced by a tectonic seafloor deformation of arbitrary geometry was obtained considering the rupture kinematics. The developed solution was applied to a set of problems for wave generation by bottom motion with arbitrary spatiotemporal variations. First, a single bottom motion with different uplift speeds was considered; results showed that relatively fast uplift speed produces increased free surface elevation at the center of the movable bottom. For dual bottom motion with spatial and temporal intervals, the free surface elevation at the end of entire uplift motion has different maxima at different positions depending on their intervals. Then, the bottom motion subdivided into 10 sub-regions with rupture velocity and uplift speed was considered. The result implies that when the rupture process is introduced in the solution, the wave energy in the direction …

We investigated, from two laboratory experiments, the kinematic behavior and the three-dimensional turbulence that is generated due to a breaking solitary wave propagating over irregular shallow water bathymetry. The bathymetry was composed of a deep water region followed by a shallow shelf via a relatively steep slope. The offshore boundary of the shelf break varied in the longshore direction. The shelf had a triangular shape in plan view, with the widest part of the shelf located along the center of the basin. The first experiment used a planar shelf, while an obstacle in the shape of a conical island was placed near the shelf apex for the second experiment. Measurements of fluid velocities and free surface elevations were collected using three-dimensional acoustic Doppler velocimeters (ADVs) and wave gauges, respectively. In the first experiment, the inundating flow varied weakly in the alongshore direction …

We develop the third-order adaptive Adams-Bashforth time integration and the second-order finite difference equation for variable time steps. We incorporate these schemes in the Celeris Advent software to discretize and solve the 2D extended Boussinesq equations. This software uses a hybrid finite volume–finite difference scheme and leverages the GPU to solve the equations faster than real-time while concurrently visualizing them. The newly added adaptive scheme significantly improves the robustness of the model while providing faster computational performance. We simulate several benchmarks using the adaptive time stepping scheme of Celeris Advent and demonstrate the capability of the software in modeling wave-breaking, wave runup, irregular waves, and rip currents. Program Summary Program title: Celeris Advent (v. 1.3. 4) CPC Library link to program files: https://doi. org/10.17632/pwsjdsgz89. 1 …

In this study, atmospheric motion vectors (AMVs) were derived from the satellite images predicted using a generative adversarial network (GAN) and a deep multi-scale frame prediction algorithm. The GAN was trained and tested with a sequence of the satellite images of a COMS satellite infrared-window channel under the 68 tropical cyclones. The inputs of the consecutive satellite images with 15-min interval were then processed using the trained GAN model to generate satellite images in the next time steps. To further enhance the model’s predictability, particle image velocimetry based on the theory of cross-correlation schemes was employed to the GAN-generated satellite image sequence and AMVs were produced. The GAN-derived AMVs were validated with the wind fields based on the numerical weather prediction (NWP) and radiosonde observations. The comparisons showed that the GAN-derived AMVs …

Future storm-induced inundation risks were assessed by performing storm surge modeling based on Typhoon Maemi (2003) under the generic climate change scenarios proposed by IPCC AR5. The three physical factors governing the projected aggravation of inundation damage in a coastal basin (i.e., sea-level rise (SLR), direct runoff (DR) and tropical cyclones (TCs)) were defined and considered in the modeling both individually and in combination. With the application of a coupled hydrodynamic–hydrologic model, the inundation extent during the storm event under both current and year 2100 climate conditions was evaluated, and the impact of each factor on the inundation risk was identified. The intercomparison among the results revealed that SLR was the most influential single flooding driver aggravating the future inundation risk, and TC intensification was two-thirds as influential as SLR. However, DR was …

Over the last several decades, various analytical, numerical and experimental studies have reported that leading-depression N-type tsunamis could be more destructive than leading-elevation N-type tsunamis. However, in many analytical or experimental studies, the effects of shelf geometry and wave breaking under the geophysical scale, which are known to significantly affect tsunami evolution, have been ignored. Therefore, it is still unclear whether leading-depression tsunamis always result in more serious damage than leading-elevation tsunamis if earthquakes with the same magnitude occur at the same epicentre. Thus, this study investigated the runup and wave evolution characteristics of idealized leading-depression and leading-elevation tsunamis, particularly considering the effects of shelf geometry and wave breaking under the geophysical scale. Using a Boussinesq-type model for fully nonlinear …

Generalizing the relationship between cyclonic features and storm surges remains challenging because previous studies have produced diverse results for different regions and historical events. We implemented Delft3D‐FM simulations and examined the synthetic effects of translation speed V t and landfall angle α on maximum surge height (MSH) along an open coast and bay. By simulating idealized cases with varying V t and α , we found that fast translation of a tropical cyclone (TC) magnified the MSH, with the most extreme MSH occurring when the landfall angle was almost perpendicular to the coastline. In addition, the simultaneous presence of smaller α and slower V t conditions for a TC can trigger coastally trapped waves arriving ahead of its landfall. The impacts of the Proudman and Greenspan resonances contribute substantially to the MSH, depending on the conditions of the TCs and their topographies …

A vertically discretized multi-paddle wavemaker is proposed that generates various wave types without the depth-invariant flow condition limitation associated with conventional piston type wavemakers. A first-order mathematical formulation for the paddle stroke is derived and used to selectively generate free surface waves similar to either piston type or flap type wavemakers, depending on the number of utilized paddles. The mathematical formulation is further extended to a multi-phase internal wave case. Paddle discretization performance is evaluated using OpenFOAM, a numerical model that solves the Navier-Stokes equations for two (or more) immiscible and incompressible fluids. Dynamic meshing capability is incorporated in the model. Model results show multiple discrete paddles efficiently generate deep water waves under laminar flow conditions. In intermediate wave conditions, the multi-paddle …

Coastal Hydrodynamics Lab

교수님 소개

손상영

연구실 소개

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

A Second-order Well-balanced Reconstruction for the Shallow Flows with Wet/dry Fronts

An Interactive Nearshore Wave Simulator for Rapid Design Prototyping and Natural Hazard Education

A random forest-based method for reconstructing pressure fields in tropical cyclones from wind data

연구실 보유 특허

대학별 입시끈

우리 연구실 모집

교수님 소개

손상영

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

A Second-order Well-balanced Reconstruction for the Shallow Flows with Wet/dry Fronts

An Interactive Nearshore Wave Simulator for Rapid Design Prototyping and Natural Hazard Education

A random forest-based method for reconstructing pressure fields in tropical cyclones from wind data

연구실 보유 특허

최근 3년간 연구실적 높은 연구실

대학별 입시끈

우리 연구실 모집