There is significant variation in wind deployment by country, and national capacity rankings and weighted resource indices are not able to separate out physical resources from market, policy and electricity-system constraints. This study proposes a physically interpretable and statistically adjusted global assessment of wind deployment based on 132 country and territory capacity records for 2014–2023, an inventory of onshore wind resources based on Google Earth Engine mapping of 201 geographical units, and published global offshore technical-potential data from World Bank — ESMAP. Onshore eligibility was screened at a nominal scale of 1 km, with wind speed data from the Global Wind Atlas, elevation-derived slope from the MERIT data, built-up intensity from the Copernicus data and the World Database on Protected Areas. Fifteen scenarios were selected that involved wind speeds of 5.0–7.0[Formula: see text]m/s and capacity densities of 3–7[Formula: see text]MW/km 2 ; the central scenario included wind speeds [Formula: see text] [Formula: see text]m/s and a capacity density of 5[Formula: see text]MW/km 2 . Installed capacity grew from 371.2[Formula: see text]GW in 2014 to 1049.4[Formula: see text]GW in 2023 and the 10 largest markets accounted for 84.0% of the 2023 sample. Absolute potential (299 210[Formula: see text]GW) was found to be a function of assumptions as illustrated by the range of scenario totals between 147 905[Formula: see text]GW and 424 390[Formula: see text]GW. However, country rankings remained highly stable (median Spearman [Formula: see text]). The resource-only model used 126 countries and achieved an out-of-sample [Formula: see text] of 0.201, whereas the structural-policy model used 96 countries and achieved an out-of-sample [Formula: see text] of 0.629. The HC3 coefficient estimates for technical potential, electricity demand, GDP per capita, RISE policy readiness and grid losses were positive. Grid losses were treated as an imperfect electricity-system proxy, and their positive coefficient was interpreted noncausally. The leave-one-country-out jackknife[Formula: see text] intervals performed well with empirical coverage of 96.9% and identified three countries whose observed capacities fell below the expected range. Eight countries were hotspots in all 15 scenarios. Only Sudan and Algeria were both universal physical hotspots and below the structural prediction interval. New Zealand’s combined potential ranked 24th and remained within the expected range, showing that high wind speed alone is insufficient for classification.
Jack-up platforms are critical for offshore oil and gas operations, yet their structural integrity under complex environmental and operational loads remains a primary design challenge. This study presents a systematic investigation into the structural behavior of a jack-up platform, uniquely incorporating lateral forces from the drilling rig alongside extreme environmental loads and a mooring system. Utilizing a comprehensive finite element model in Structural Analysis Computer System (SACS) software, we conducted extensive parametric analyses to hierarchically quantify the influence of wave-height, wave period, wind speed, and current speed. A key finding is the non-negligible role of current speed, whose impact on structural stress is demonstrated to be comparable to that of wind speed. The results clearly show that wave-height is the dominant factor governing leg strength. Furthermore, the study provides a quantitative comparison between idealized pinned supports and more realistic Pile–Soil Interaction (PSI) models, offering a practical framework for selecting appropriate boundary conditions at different design stages. We also reveal that the introduction of a mooring system profoundly alters the load-bearing mechanism, significantly reducing stress on the legs and spudcans but concentrating risk onto the mooring lines themselves.
Phase-resolving depth-integrated models are important tools for modeling nearshore wave transformations in coastal engineering applications. Since depth-integrated models are reduced-order models, some important physical processes including boundary layer processes, turbulence processes, and wave breaking processes need to be parameterized in the models. When depth-integrated models are applied in a wave flume environment, sidewall effects also need to be parameterized. This study adopts a nonhydrostatic model to simulate a set of large-scale wave flume tests designed to study characteristics of breaking waves in a wave flume setting with a bathymetry representing an idealized fringing reef. Selection of grid size is discussed based on the size of a roller. This study explores the possibility of using the eddy viscosity to parameterize the effects of the sidewall boundary layer, the capillary hysteresis associated with the meniscus formed at the contact lines and possible surface contamination. A procedure and recommendation are presented for calibrating the breaker model using wave flume test results to better describe (i) the onset/cessation of a wave breaking event and the energy dissipation associated with the wave breaking, and (ii) the transformation of breaking waves in a reef environment. Limitations of the adopted model are also discussed.
Coastal regions around the world are undergoing significant changes due to a complex interplay of natural processes and human activities. The city of Mohammedia, located along the Atlantic Ocean coast of Morocco, is no exception to these coastal dynamics. This study presents a comprehensive analysis of the morphological evolution of the Mohammedia coastline from 1969 to 2023, focusing on shoreline erosion and the factors influencing these changes. the research identifies significant erosion along Monika Beach and Sablette Beach, reaching an alarming rate of approximately −2.15[Formula: see text]m per year between 1996 and 2023. Human activities, including urban expansion and port development, have played a central role in these coastal changes.
Plunger-type wavemakers have been installed in many ocean laboratories around the world, yet there still lacks the wavemaker theory for cnoidal waves, mainly due to the complexity of the cnoidal wave theory and plunger geometry. In this paper, motion equations for a cylinder-shaped plunger generating cnoidal waves, along with constraints on wave parameters, are derived. Afterwards, the generation of cnoidal waves is simulated in a Smooth Particle Hydrodynamic (SPH) wave flume, the accuracy of which is pre-examined by reproducing a laboratory experiment in the literature. Computational results are in satisfactory agreement with analytical solutions in terms of wave height, wave period, pressure and flow velocity. Moreover, pressure fields remain stable during both wave generation and propagation. It can be anticipated that the derived wavemaker theory will extend the functionalities of existing cylinder-shaped plungers and benefit plunger design in the future.
The fluid–soil interactions play a significant role in coastal and ocean engineering applications. However, there are still some complex mechanical problems with large deformations of water–soil interfaces to be solved. As a particle-based Lagrangian method, Smoothed Particle Hydrodynamics (SPH) is good at solving multiphase problems with large deformations of boundaries or interfaces. Therefore, in this work, the [Formula: see text]-SPH method is extended for the simulation of fluid–soil interacting problems. First, based on the weakly compressible assumption, the water is modeled as a viscous fluid while the soil is considered as a material with elastic–perfectly plastic behaviors. The [Formula: see text]-SPH method is implemented on the two phases separately, while the stress diffusive term only acts on the soil. The seepage force is introduced to model the interaction between two phases. After that, several numerical test cases with small to large interface deformations are presented. It is shown that the fluid–soil interacting model based on the [Formula: see text]-SPH model gives satisfying results compared with experimental data. Finally, the model is further extended for the simulation of vertical or oblique water jet scouring problems which demonstrates the potential applications of the SPH model for complex engineering problems.
The wave impact on marine structures is concerning in ocean and coastal engineering. Cylinders are important components of various marine structures such as piers of sea-crossing bridge, columns of oil and gas platforms and subsea pipelines. In this study, the interaction of solitary wave with a submerged horizontal cylinder and a surface-piercing vertical cylinder are numerically studied by the Smoothed Particle Hydrodynamics (SPH) code SPHinXsys. SPHinXsys is an open-source multi-physics library based on the weakly compressible SPH and invokes the low-dissipation Riemann solver for alleviating numerical noises in the simulation of fluid dynamics. The capability of SPHinXsys in reproducing the fluid fields of solitary wave propagating through cylinders is demonstrated by comparing with the experimental data. With the validation in hand, the features of the wave–structure process are examined.
In this paper, we presented the multi-rational solution of the time-dependent [Formula: see text]-dimensional Boiti–Leon–Manna–Pempinelli (BLMP) equations. We have used the generalized unified technique to construct multi-rational wave solutions for the BLMP equations. We included the representative solution plots corresponding to designated arbitrary functions in the solutions, which provide a physical insight about the structure of the solution. The interaction solution among lump wave, 1-soliton and periodic wave is presented. The breather-wave solution is obtained. Dynamical behavior is shown by abundant 3D, density and contour plot.
Physical protection of nearshore pipelines from marine life, ocean waves, and shipping activities is of critical importance in offshore engineering to guarantee reliable transition of energy. Mechanical damages such as buckling, dent, and cracks generated due to anchor-hooking threaten pipeline stability and need to be addressed from both engineering and scientific perspectives. In this study, we conduct a series of experimental and numerical simulations to investigate the interaction between an anchor and a trenchless rock berm constructed on soft saturated seabed, while the pipeline is laid in the berm. The experiments are performed in 1[Formula: see text]g tank, and the numerical tests are simulated with Coupled Eulerian–Lagrangian (CEL) finite element method. This study extends the available soil passive force formulation for the interaction of anchor–soil and compared its results with the numerical and experimental results. There is good agreement between the predictions of the numerical model and the experimental results. In addition, our work extends the available approaches to estimate soil passive forces for a dragged anchor. The stiffness of seabed and rock berm is important in the design of rock berm.
Artificial revetments are commonly constructed on reef-flats to protect the rear infrastructure. Evaluating the performance of a revetment under extreme wave conditions requires accurate prediction of wave overtopping. To simulate tsunami wave overtopping on an artificial revetment above a coral reef-flat, a numerical model based on the weakly compressible smoothed particle hydrodynamics (WCSPH) method is developed. This numerical model includes an additional dissipative term in the continuity equation and a dynamic boundary condition enhancement to correct the pressure distortion from particles at the boundary. Reef topography is simplified as a steep reef-face and a horizontal reef-flat, and tsunami waves are described as solitary waves. This research explores the characteristics of solitary wave overtopping on the revetment above the reef-flat with varying slope angles and reef-flat lengths.
Beaches provide protection to residents living near the ocean by acting as a buffer against the high winds and waves of powerful storms or rough seas. It also helps the government to increase revenue and the development of infrastructure. Because beaches are very accessible to humans, it is very important to go through the demerits that are causing changes in the beaches and what steps can be taken to prevent the beaches from evolving. There are several studies indicating that there is an increase in the wave heights and wave periods along the Indian coasts, with maximum wave heights increasing by more than 30% in some of the locations. It is also found that at most of the locations along the east coast, wave periods are expected to increase by almost 20% whereas along the west coast, they are expected to increase by around 10% [ Chowdhury et al. [ 2019 ] “Wave climate projections along the Indian coast,” Int. J. Climatol. https://doi.org/10.1002/joc.6096 .]. This will alter the distribution of wave energy at the shoreline, swash-aligned beaches and additionally the design of coastal structures. It is particularly important to evaluate the wave characteristics and sediment transport which leads to erosion and/or siltation problems along the Indian coasts. In this paper, an extensive review on wave hydrodynamics, sediment transport and coastal erosion is compiled along the Indian coasts.
Tidal inlets are an ecologically sensitive and significant constituent of the coastal environment, where an opening along the shoreline permits the free exchange of fresh and seawater. Predominant longshore currents along the shore result in the formation of sandbars, spits and shoals. Frequent occurrence of such sediment depositions acts as barriers, preventing the ingress of tidal flow. Conventionally training walls are constructed at the inlet to prevent sandbar and spit formations. The volume of water exchanged at the inlet mouth and ebb tidal currents primarily govern the inlet dimensions and the rate of littoral transport, respectively. The case study of a trained micro-tidal inlet at Karaikal (10[Formula: see text]52[Formula: see text]N; 79[Formula: see text]E), India is discussed in this paper. A numerical model using the finite volume method is applied to estimate the siltation rate and distribution within the study domain, driven by tide-induced currents and riverine discharge. A revetment structure is proposed to combat siltation within the inlet to facilitate smooth navigation. The study highlights the notable changes in the presence and absence of the proposed revetment.
In the 1990s, oceanographers realized that the freak waves posed realistic threats to offshore and marine engineering. Since then, tremendous efforts from both academia and industry have been made to reveal the physics of freak waves as well as their effects on structures. Despite the need for a uniform and robust definition and the ongoing discussion of the dominant mechanism, significant advances have been achieved in understanding freak waves in various aspects. As an emerging explanation of freak wave formation, the nonequilibrium dynamics has received much attention, as it provides insights into nonlinear focusing under complex changing environmental conditions. The new techniques for the generation or reproduction of freak waves are of higher efficiency and accuracy in terms of enhancing maximum wave height and controlling the focusing position and time. Besides, sidestepping the complex physical mechanisms, the machine learning, as a data-driven technique, provides an alternative approach for the investigation of freak waves. Tracking these new developments is the target of this review paper, the limitation of the current works and future perspectives are also discussed.
In the recent years, various geo-synthetic components find an extensive application in civil and coastal engineering practice. Commonly, geo-synthetics have a wide application for secondary or tertiary purposes, such as filtration, separation, barrier, reinforcement, whereas, they can be potentially exploited for various other applications in the coastal engineering practice. A sustainable seawall cross-section comprising different geo-synthetic products was proposed to be erected along the Pallana Beach ([Formula: see text] N and [Formula: see text] E), located in Alleppey district of Kerala along the south-west Indian coastline. Since the subsoil at the location is poorly graded, it was decided to replace the conventional materials like rock boulders and concrete armour units with geo-synthetic products. A comprehensive physical model study was conducted to assess the hydrodynamic performance (i.e. reflection, run-up, and pressure distribution) of the geo-synthetic seawall cross-section for a wide range of random wave characteristics and two water depth conditions. The relative overtopping rates for the seawall at varying water levels are computed conservatively from the guidelines prescribed by the EurOtop Manual and XGB Overtopping model.
This case study reports results from field observations and numerical simulations of waves and morphological changes along a portion of Kaanapali Beach on West Maui, Hawaii, which is protected by a hard coral reef and experiences shoreline changes from season to season. The SWAN spectral wave model shows reasonable agreement with ADCP observations of wave-heights for the winter months. Simulated beach profile change over one-month time frame was able to reasonably capture the trend of beach face migration (accretion or erosion); the modeled shoreline also shows satisfactory agreement with beach survey data. This case study suggests that Delft3D is able to capture key features of sediment transport along a narrow beach protected by a fringing reef.
This study focuses on the application of structured cementing technology in the marine environment, which is based on self-compacting cement-based materials and underwater self-protecting casting cementing technology. In this study, cylindrical samples of structuralized cemented stone columns are developed in the laboratory to test material strength and other key features related to the material. Following this line, extensive numerical experiments are conducted to investigate the interaction between in situ sea mud and cemented stone column-seawall systems. The methods developed in this study will provide a technical basis for understanding the behavior of the newly invented cemented stone column-seawall system from a numerical perspective.
Potential tsunamis in the western Pacific Ocean pose great threats to the Chinese coastal areas. Among all possible tsunami source regions, the Manila subduction zone draws the most attention and there have been many research works on the tsunami hazards in the South China Sea. In this study, we evaluate the tsunami hazard along the Chinese coast by investigating more potential sources, including the subduction zones of Manila, Ryukyu, Nankai, Izu–Bonin and Mariana. Two tsunami scenarios are considered for each subduction zone, a worst scenario of earthquake magnitude 9.0 and a scenario of largest earthquake magnitude known in history in this zone. Earthquake source parameters are calculated using scaling relations that have been shown to be suitable for tsunami generation. Our results show that for the Chinese coast, tsunami hazards from the Manila and Ryukyu subduction zones are severe in the worst scenarios, and tsunami hazards from the Nankai, Izu–Bonin and Mariana subduction zones are mild. Using the largest earthquake magnitude in history, tsunami hazards from all the investigated subduction zones are almost negligible. Through a sensitivity test on earthquake magnitude, we find that earthquakes of magnitude of 8.5 or larger in the Manila and Ryukyu subduction zones cause severe tsunami hazard along the Chinese coast with wave amplitude over 2 m.
The entrained air and turbulence characteristics under a breaking solitary wave on a 1:20 sloping beach are investigated through laboratory measurement. Free surface elevation is obtained from wave gauge measurements. Wave breaking process is captured in detail by a high-speed camera. The bubble image velocimetry (BIV) is used to measure the velocity and the fiber optic reflectometer (FOR) is used to capture instantaneous void fraction in the aerated region. The mean void fraction and velocities in the aerated region are obtained by ensemble averaging over 22 repetitions. Results show that the maximum mean void fraction is 0.6 in the collapsing cavity region and is 0.35 in the splash up region. The time series of the mean void fraction has good synchronization with the instantaneous images taken by high-speed camera. The maximum horizontal velocity occurs in the splash up region and reaches 1.17C shortly after the plunging jet hits the water surface, with C being the phase speed of the primary wave. The turbulence intensities over the entire aerated region are presented and discussed. The measured data can be used for the calibration and verification of the numerical model for aerated flows simulation under breaking waves in the surf zone.
In general, people like to live near the coast because of a better aesthetical pleasing living environment, access to a variety of recreational activities and more job opportunities. Consequently, more than 50% of the world’s population live within 200[Formula: see text]km of the coast, and ¾ of the world’s megacities are situated by the shore. Significant pressure on land, water supply, waste management and other infrastructures appear in these coastal cities. India, which hosts one-sixth of the world’s population is looking for strategies to manage India’s coastal cities, water, land and human resources. This paper reviews China’s experience in water resources development for coastal cities. China’s coastal economic corridor (CEC) contributes 60% of the national GDP, which needs plentiful water supply to sustain its coastal cities. The present investigation shows that India has better natural conditions to develop its CEC. Among the coastal infrastructures, coastal reservoirs (i.e., CRs) should be the priority, which nourishes the coastal prosperity. This paper also discusses the feasibility of water–oil exchange project between India and Persian Gulf countries.
The purpose of this research work is to study the diffraction of surface gravity waves propagating through rectangular porous medium in three dimensions. The considered porous structure consists of dense arrays of surface piercing vertical cylinders. Experiments for different regular wave conditions have been carried out, especially for three-wave frequencies. The experimental data of wave refraction–diffraction and reflection have been compared to computed results from potential linear theory solved with an integral matching method. Comparison with a previous 2D study about wave propagation through porous medium in a 10 m long wave flume is also discussed in order to highlight the refraction–diffraction effect due to the porous structure.
