Harshinie Karunarathna

Harshinie Karunarathna
Swansea University | SWAN · Zienkiewicz Centre for Computational Engineering

MSc (Lond), DIC, PhD (Saitama)

About

165
Publications
41,829
Reads
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1,652
Citations
Introduction
Harshinie Karunarathna currently works at the Zienkiewicz Centre for Computational Engineering, Swansea University. Harshinie does research in Coastal Engineering and climate change impacts. Their current project is 'CoastWEB: Valuing the contribution which COASTal habitats make to human health and WEllBeing, with a focus on the alleviation of natural hazards'.
Additional affiliations
March 2017 - present
Swansea University
Position
  • Professor
July 2013 - February 2017
Swansea University
Position
  • Professor
January 2012 - June 2013
Swansea University
Position
  • Professor (Associate)

Publications

Publications (165)
Article
Full-text available
As storm-driven coastal flooding increases under climate change, wetlands such as saltmarshes are held as a nature-based solution. Yet evidence supporting wetlands’ storm protection role in estuaries - where both waves and upstream surge drive coastal flooding - remains scarce. Here we address this gap using numerical hydrodynamic models within eig...
Preprint
Full-text available
As storm-driven coastal flooding increases under climate change, wetlands such as saltmarshes are held as a nature-based solution. Yet evidence supporting wetlands’ storm protection role in estuaries - where both waves and upstream surge drive coastal flooding - remains scarce. Here we address this gap using numerical hydrodynamic models within eig...
Article
A computational model has been used to explore characteristics of the barotropic tide around the Welsh coast in detail for the first time. Proper understanding of tidal characteristics is vital for the sustainable use of marine resources; particularly for industries such as marine energy extraction, aggregate mining, aquaculture, as well as regulat...
Article
Full-text available
Gravel beaches and barriers form a valuable natural protection for many shorelines. The paper presents a numerical modelling study of gravel barrier beach response to storm wave conditions. The XBeach non-hydrostatic model was set up in 1D mode to investigate barrier volume change and overwash under a wide range of unimodal and bimodal storm condit...
Chapter
A new semi-analytical solution to the one-line model is presented in this work which can be used for the description of complicated coastal systems. An application of the semi-analytical model to Borth case study in Wales, UK, is presented. Additionally, Calangute beach in Goa, India, will be discussed as a future case study where the model will be...
Chapter
“The aim of this article is to provide an introductory review on coastal engineering, emphasizing beach and shore protection. It is intended as a reference guide to a senior undergraduate or early career researcher who wants to pursue the topic to understand it at more than a superficial level. A brief history of the development of coastal engineer...
Article
Full-text available
The ability of coastal vegetation to attenuate waves has been well established (Moller et al., 2014). Salt marshes are vegetated coastal wetlands that can act as nature- based coastal defenses. They exhibit a range of plant species, which have been shown to differ in the amount of wave damping they provide (Mullarney & Henderson, 2018). Recent stud...
Article
Full-text available
Coastal vegetation such as seagrasses, salt marshes, and mangroves, contributes to coastal defence by damping incoming waves. Yet, plant species differ in flexibility due to which they interact differently with incoming waves and damp waves to a variable degree. Current wave damping models struggle to balance accuracy against computational costs wh...
Article
Full-text available
Coastal dunes have global importance as ecological habitats, recreational areas, and vital natural coastal protection. Dunes evolve due to variations in the supply and removal of sediment via both wind and waves, and on stabilization through vegetation colonization and growth. One aspect of dune evolution that is poorly understood is the longshore...
Article
Reduction of risks due to overtopping of coastal defences is an essential requirement for the design, management and adaptation of coastal structures. Extensive knowledge is available on the prediction of overtopping of smooth, sloping and vertical impermeable seawalls. The existing prediction methods provide less certain guidance for combined wind...
Conference Paper
Full-text available
Turbulent flow over stepped spillways can be considered the most significant flow that can cause severe problems at the downstream side, near the toe of the structure, such as sediment erosion which normally occurs due to the high amount of water energy. The presence of turbulent flow over the steps can cause cavitation damages due to pressure diff...
Article
Full-text available
This study investigates the impacts of global climate change on the future wave power potential, taking Sri Lanka as a case study from the northern Indian Ocean. The geographical location of Sri Lanka, which receives long-distance swell waves generated in the Southern Indian Ocean, favors wave energy-harvesting. Waves projected by a numerical wave...
Article
Full-text available
Saltmarshes are considered as natural coastal defences. However, owing to the large context dependency, there is much discussion over their effectiveness in providing coastal protection and the necessity of additional coastal defence interventions. The macro-tidal Taf Estuary in south-west Wales was chosen as the case study in this paper to investi...
Article
Full-text available
Vegetation can contribute to coastal defence by damping incoming waves. However, prior studies have shown that attenuation varies greatly among plant species. Plant flexibility is a mechanical property that is commonly omitted, but varies considerably between shrubs and grasses on salt marshes. Therefore, we present an experimental study in a labor...
Article
The paper presents a detailed analysis of the spatio-temporal variability of wave power resource around Sri Lanka, using computationally simulated 25 years of wave data that represents the prevailing ocean climate in the region. The computational wave model was validated against a measured wave dataset collected over a 44-month period at 70 m water...
Article
Full-text available
Understanding of the reflection characteristics of coastal seawalls is crucial for design. Wave reflection can cause difficulties in small vessel manoeuvring at harbour entrances; this can cause damage to the toe of coastal structures by scouring. Previous studies have examined the reflection characteristics of coastal seawalls under random wind-ge...
Article
Full-text available
Beach profile evolution under storm sequence forcing presents an emerging research topic that has only been investigated at a limited number of sites. The occurrence and effects of storm sequencing on beach profile evolution are studied at Hasaki Beach, Japan, using weekly beach profile and two-hourly offshore wave measurements. During the 25-year...
Article
Full-text available
Better understanding of the global wave climate is required to inform wave energy device design and large-scale deployment. Spatial variability in the global wave climate is analysed here to provide a range of characteristic design wave climates. K-means clustering was used to split the global wave resource into 6 classes in a device agnostic, data...
Preprint
Understanding of reflection characteristics of coastal seawalls is crucial for design. Wave reflection can cause difficulties to small vessel manoeuvring at the harbour entrance and constitute damaging scouring at the toe of coastal structures. Previous studies have considered reflection characteristics of coastal seawalls under wind-generated rand...
Conference Paper
Full-text available
Prediction of wave overtopping is a crucial component of coastal structure and seawall designs. Modelling efforts have improved coastal seawall construction design and have saved construction costs. Despite a large amount of research on wave overtopping as published in the EurOtop (2018), there are still knowledge gaps to be considered in terms of...
Article
Full-text available
Global climate change drives sea level rise and changes to extreme weather events, which can affect morphodynamics of coastal and estuary systems around the world. In this paper, a 2D process-based numerical model is used to investigate the combined effects of future mean sea level and storm climate variabilities on morphological change of an estua...
Article
Full-text available
Purpose Coastal flooding has disastrous consequences on people, infrastructure, properties and the environment. Increasing flood risk as a result of global climate change is a significant concern both within the UK and globally. To counter any potential increase in future flooding, a range of potential management options are being considered. This...
Conference Paper
Full-text available
The use of saltmarshes as an intervention to alleviate the effects of coastal flooding has gained increasing intention due to climate change. A coupled Delft3D FLOW-WAVE model was developed for the macrotidal Taf estuary in South West Wales to assess how three different interventions on saltmarsh management affected coastal flooding. An extreme sto...
Article
Full-text available
This paper reviews and discusses the current research status, trends, and future needs in the field of beach morphodynamics under the influence of storm sequences. The paper reviews how the three main research methods, field investigations, numerical modelling, and physical modelling, have been used to study beach morphodynamics during storm sequen...
Conference Paper
Full-text available
Salt marshes are coastal wetlands that can reduce flood risk by their vegetation. The drag that salt marsh plants induces on currents modifies estuary hydrodynamics which affects flood water levels, surge propagation and sediment transport. Four parameterisations to model the drag by vegetation on currents have been proposed in literature: (i) a fi...
Article
Full-text available
The tidal energy sector is a growing industry in the UK and beyond. Energy developers’ interests are progressing towards the deployment of large arrays of tidal energy converters (TECs). Numerous factors will affect decision making related to arrays siting and size. One key factor is the effect that the TEC arrays may have on the natural sediment t...
Article
Full-text available
Tsunamis are among the most destructive natural hazards and can cause massive damage to the coastal communities. This paper presents a first numerical study on the tsunami-like solitary wave impinging and overtopping based on the mesh-free Consistent Particle Method (CPM). The distinct feature of CPM is that it computes the spatial derivatives in a...
Article
The twin ambits of climate change and coastal development have raised public awareness of shoreline management. Simultaneously, they have highlighted a gap in our understanding of sediment transport and morphodynamic processes at time and space scales appropriate for shoreline management purposes. Here, we analyse an exceptional set of beach survey...
Article
Full-text available
Global climate variabilities have the potential to impact many coastlines around the world, and can have detrimental effects on the stability of coastlines and their function as natural coastal defenses. This paper investigates the impacts of future extreme storms and sea level rise on morphodynamics of the macro-tidal Sefton Coast, UK, taking a pr...
Conference Paper
Full-text available
The tidal energy sector attracts developers' interest worldwide. For potential tidal energy deployment sites, numerous factors will impact decision making process related to siting and size of the tidal energy converter (TEC) farms. A key factor is the effect that TECs may have on the natural coastal hydrodynamic and morpho-dynamic environment. In...
Article
Full-text available
Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provide an additional challenge to the computational modeller in that flow through the porous gabions must be simulated. We have used a co...
Preprint
Full-text available
This paper presents the results of a sensitivity study investigating beach/dune response to offshore wave boundary forcing. The modelling study was based on the convex-shape Sefton coast, UK which has a complex nearshore morphology and foreshore frontal dunes. Simulations were performed using a cascade of nested grids to transform offshore waves up...
Conference Paper
Full-text available
Salt marshes are vegetated tidal wetlands, which can typically be found at sheltered coastal areas in moderate climate zones. Their potential as natural coastal protection by wave attenuation (Möller et al, 2014), reduction of flood-surge propagation (Stark et al., 2016) and shoreline stabilization (Bouma et al, 2014) has been increasingly recogniz...
Article
Bimodal seas are usually characterised by the combination of swell and locally generated wind energy. Understanding the percentage of the swell component (SC) and the wind component (WC) partitioned from the energy content of a Wave System (WS) is important in coastal defense design and management. The South Wales and southwest England wave climate...
Article
Full-text available
As anthropogenic use of the coastal zone diversifies, for example marine energy extraction, the coastal environments of interest to coastal engineers and managers is becoming more varied. Increasingly, the morphodynamics of geomorphologically complex, mixed sediment and geologically constrained beaches are important. Even in areas where erosion and...
Article
The Severn Estuary (west coast of UK) is a highly dynamic environment and thus understanding of sediment transport under both natural and man-made changes is vital to the sustainable use of the coastal area in this region. The area is likely to be the site of the world’s first tidal energy lagoon. The construction and operation of the lagoon will r...
Article
Tidal inlets, a common feature along coastlines globally, can be significantly affected by the impacts of global climate variabilities. Computational models provide the best opportunity to assess future changes to the dynamics of inlet systems. In this paper, the morphodynamic response of a gravel-dominated meso-tidal estuary inlet to Sea Level Ris...
Article
Full-text available
This paper presents an analysis of wave recordings with particular attention to assessing bimodality of the incident wave energy spectra and the occurrence of swell along the south and south-west coasts of the United Kingdom, (UK). A procedure is developed to perform an intensive analysis of a new and large dataset of measured wave spectra. A storm...
Article
Full-text available
Medium/long term trends (annual to decadal scale) of beach change are mostly used to make coastal management decisions. However, short term, extreme episodic events (short term) can erode the beach to exceed sustainable erosion thresholds thereby impacting long term trends of coastal change. Therefore, understanding coastal change at short and medi...
Poster
Full-text available
Using the PIV technique to measure the velocity profiles over gabion stepped spillways and normal stepped spillways under dam break conditions.
Article
Extraction of energy from tidal streams has the potential to impact on the morphodynamics of areas such as sub-tidal sandbanks via alteration of hydrodynamics. Marine sediment transport is forced by both wave and tidal currents. Past work on tidal stream turbine impacts has largely ignored the contribution of waves. Here, a fully coupled hydrodynam...
Article
Full-text available
The work presents a methodology to assess the coastal impacts during a storm event which caused significant damage along the promenade at Aberystwyth, Wales on the 3 January 2014. Overtopping was analysed in detail for a section of promenade by downscaling offshore wave conditions to force a surf zone hydrodynamic model, NEWRANS. Overtopping discha...
Conference Paper
Full-text available
Energy dissipation is one of the most important issues in spillway design as the downstream water flow can be highly energetic, which may lead to the creation of a scour hole in the downstream region. As a means of dissipating energy, stepped spillways can be used. The presence of steps can generate greater flow turbulence dissipating more energy t...
Conference Paper
Future storm impacts on dune evolution due to changing storm frequency were simulated in XBeach at an exemplary dune system, Formby Point, UK. Probabilistic approaches were used to establish the future storm clusters from 2015 to 2065 in three scenarios, using measured data in Liverpool Bay. Cross-shore profile simulations were carried out in two s...
Conference Paper
Full-text available
The purpose of this work was to develop a computational process to investigate the effect of bimodal wave conditions on wave overtopping. The numerical model NEWRANS has been validated for the application of bimodal wave overtopping and a procedure developed to generate the desired wave conditions in the flume. When applied to bi-modal specific wav...
Poster
Full-text available
The purpose of this work was to develop a computational process to investigate the effect of bimodal wave conditions on wave overtopping. The numerical model NEWRANS has been validated for the application of bimodal wave overtopping and a procedure developed to generate the desired wave conditions in the flume. When applied to bi-modal specific wav...
Conference Paper
This paper investigates the morphodynamic response of the Deben Estuary, which is located in the southeast of the United Kingdom (UK), to possible extreme wave change in the future. The 1 in 100-year extreme wave condition derived from global climate simulations from the MRI-GCM3,2H model has been used. Three different representative bathymetry sta...
Conference Paper
Full-text available
A set of storms, with varying intensity and duration, was used to investigate the range of morphological impacts on a macro-tidal beach (Sefton coast, Liverpool Bay, UK), using a nested computational modelling framework. Extreme wave and water level conditions were extracted from modelled and observed data corresponding to a range of return periods...
Conference Paper
Full-text available
This paper presents the application of a morphodynamic model based on 2D reduced-physics principles to investigate morphology change of a complex estuary inlet system in the United Kingdom. The model combines a simple governing equation with a set of measured bathymetry data in order to model morphology change. The modelling method suggests that th...
Article
Full-text available
A 3D numerical modelling study to investigate the existing hydrodynamic regime of the Pentland Firth Inner Sound Channel, Scotland, UK is presented. Hydrodynamics that govern some sensitive sedimentary deposits in the Inner Sound Channel are discussed. A 3D hydrodynamic model Delft3D is set up for Pentland Firth, located between Orkney Islands and...