Shore Protection Research Articles

Effects of nourished beach morphology on storm response

AbstractField observations on storm induced beach changes are important to improve our effort on beach management. This study compared storm induced beach changes caused by hurricane Hermine in 2016 (4 years after a beach nourishment) and Tropical Storm Eta in 2020 (2 years after a beach renourishment) along the barrier-island coast of west-central Florida. Pre-Eta beach were 1 to 2 times wider than that of pre-Hermine. Since Hurricane Hermine and TS Eta generated a similar hydrodynamic condition for the study site, comparing beach changes induced by these two storms provides a unique opportunity to investigate the response of different antecedent beach conditions to energetic events. The shore protection effect of beach nourishment is apparently evidenced by the fact that post-Eta shoreline was located seaward of those post-Hermine at half of the beach-profile locations in the study area. The shore protection effect in the subaerial portion of the beach, however, is not obvious for the other half of beach profiles where shoreline positions were retreated to similar locations after these two storms. Instead, their shore protection effect occurred in the sub-aqueous portion of the beach and was indicated by higher sandbar crests located closer to the shoreline, which can dissipate and reduce incoming wave energy. The shoreline elevation needs to be properly defined (Mean High Water vs Mean Low Water line) as it is used as a proxy to represent beach volume loss. For Hermine induced beach change, no significant correlation exists between MHW line change and beach volume loss. While a significant correlation exists between MHW line change and beach volume loss induced by TS Eta. This correlation pattern switched if the shoreline here is defined as mean low water line. For efficient beach/shoreline management, multiple proxies (e.g., sandbar height and location of its crest and trough) in addition to shoreline change should be used to assess the performance of beach nourishment project.

ЭКОЛОГИЧЕСКИЕ ОСНОВЫ ВЫБОРА БЕРЕГОУКРЕПИТЕЛЬНЫХ СООРУЖЕНИЙ ПРИ РЕКОНСТРУКЦИИ ПЛЯЖЕЙ КРЫМСКОГО ПОБЕРЕЖЬЯ

The relevance of improving the methods of engineering and environmental survey of coastal protection objects is determined by their existing violations, which reduce environmental safety in general and create a danger for the organization of tourism on the coast. The purpose of the study is to substantiate the choice of bank protection structures during the reconstruction of the beaches of the Crimean coast in the conditions of recreational specialization of the region. The nature and extent of deformations of the coastal zone of the sea and shore protection structures on the coast of the Kalamitsky Bay of the Black Sea are described. The authors proposed the design and location of the breakwater, which will make it possible to more effectively cope with the damping of waves during a storm period compared to classical breakwaters. Materials and methods. The study of the state of coastal territories and the solution of problems of coastal protection structures is based on the theory of geomorphology of the surface and underwater parts of the coast, the regularities of the hydrophysical parameters of the sea in the coastal zone, and climatic and seismic conditions. The methods of field observations and experimental studies in the wave basin were used to take into account the influence of natural and anthropogenic factors on the ecological parameters of the coastal zone of the Crimean coast. Results. In 2022, a team of authors carried out a visual survey of the coast in the territory of the Bakhchisaray district of the Republic of Crimea with a total length of 11.5 km. from s. Coastal to with. Angular. As a result of the inspection, sections of the coast that are potentially dangerous to the health and life of people and are not suitable for normal use for recreational purposes were identified. Conclusions. Long-term field observations show that the creation of bank protection in certain local areas, having given only a temporary positive effect for these areas, can have a very negative impact on neighboring and even remote areas; that is why the issue of protecting the coast should be resolved at least on the scale of the coast of settlements, taking into account the conditions of a single system. The shape of the coast protection structure proposed by the authors can make it possible to more effectively dampen waves compared to classical rectangular breakwaters. However, when designing coastal protection measures, it should be taken into account that separate protection of small areas of eroded coastal territories within a large zone of eroded coast is ineffective, since adjacent unprotected shores will recede under the influence of a system of natural factors.

Application of Soil-Filled Blocks in Solving Problems of Shore Protection

Application of Soil-Filled Blocks in Solving Problems of Shore Protection

RESEARCH SOLUTIONS FOR PRECAST CONCRETE REVETMENTS USING ALB-REBAR TO RETAIN CORAL SAND FOR OFFSHORE ISLANDS IN VIETNAM

Gravity revetment solutions are a popular choice for shore protection at atolls under the harsh conditions of ocean waves. The precast revetment option is preferred to reduce shipping costs for materials and ensure quick construction. This article studied precast concrete revetments with ALB composite material reinforcement and conducted experimental research to determine the shear resistance characteristics of coral sand and the friction characteristics of concrete materials with coral sand. Based on the experimental parameters, the authors calculated the stability of the ALB embankment structure against the effects of wave loads during storms. With experimental data obtained from coral sand samples prepared with equivalent density in the field, the results showed that the stability coefficient of the revetment is significantly higher than the one obtained from the traditional calculation concept.

Inducing mussel beds, based on an aquaculture long-line system, as nature-based solutions: Effects on seabed dynamics and benthic communities

Nature-based solutions (NbS) offer a promising path to enhance climate-resilient shorelines. For instance, the creation of mussel beds in subtidal sandy shore systems provides a versatile strategy for coastal management, reinforcing coastal defense and fostering biodiversity, ultimately strengthening the resilience and well-being of coastal communities. This study analysed the changes in seabed dynamics and surrounding benthic communities as a result of the formation of mussel beds (Mytilus edulis) using an aquaculture longline system. Therefore, a comprehensive monitoring approach at two sites characterized by distinct hydrodynamic conditions was applied over a three-year period. To assess the effects, a before/after control/impact design (BACI) was employed. Seabed dynamics were evaluated by observing mussel bed persistence, erosion/deposition, and sediment composition. The influence on the benthic community included assessments of community structure and biodiversity. Finally, the impact of mussels, hydrodynamic conditions, and their interactions on seabed dynamics and benthic communities was examined using linear mixed models (LMMs). Factors such as mussel presence, Lanice conchilega abundance, shell cover, and sediment composition played a role in shaping the distinct characteristics observed between two different sites: a site that lies at a location that is more sheltered from hydrodynamic conditions, and a second site that is exposed to higher current and wave conditions. The sheltered site exhibited higher species density, richness, biomass, and diversity compared to the exposed site. In relation to the mussel bed development, mussel patches were found at both sites (with higher occurrence at the sheltered site) in the 2nd and 3rd years (mainly in summer towards early winter). The influence of mussels on sediment deposition was noticeable at the sheltered site, albeit lacking statistical significance, suggesting their potential role in erosion/deposition mechanisms. Also, a higher proportion of very fine sand was observed in the mussel bed compared to the bare sand. However, due to the absence of higher-density permanent mussel beds and irregular sedimentation/erosion patterns throughout the study period, no significant effect of the mussel beds on the community structure or diversity was found. In order to achieve a sustained and dense mussel bed and maximize the potential impact of mussels in combating climate change (e.g., shore protection and biodiversity enrichment), additional measures to increase coastal resilience against harsh hydrodynamic conditions may be necessary.

Coastal resilience and shoreline dynamics: assessing the impact of a hybrid beach restoration strategy in Puducherry, India

Puducherry, a Union Territory of India, has been strongly affected by severe erosion after the construction of the Puducherry port in 1989. To mitigate this cause, the National Institute of Ocean Technology, Chennai, and the Puducherry government implemented a beach restoration strategy involving a hybrid solution in 2017 for coastal protection/stabilization and the restoration of the lost beach. The strategy involved deploying a steel reef into the nearshore sea and implementing beach nourishment processes. To monitor the coastal morphological changes after implementing the coastal protection strategy, the Digital Shoreline Analysis System, was adopted to calculate the rate of shoreline change statistics for the years 2016 to 2022. It uses spatio-temporal shoreline positions from multi-temporal satellite imagery. The shorelines are extracted from the Sentinel-2A satellite images by a Normalized Differential Water Index based semi-automated model. Statistical parameters in DSAS analyze the shorelines to determine the shoreline changes in this area. The results reveal the remarkable resilience of a newly restored beach, where the linear regression rate statistics in Zone A show an average accretional rate of 2.92m/yr. Alternatively, Zone B exhibits an average erosion rate of -0.23m/yr, with intermittent sandy beaches experiencing maximum erosion rates of -1.63m/yr. The influence of longshore current direction and sediment transport on shoreline movement is evident in seasonal analysis, with shoreline development and recession primarily observed near shore protection structures. The study’s outcome provides valuable insights for coastal management, offering a reliable approach for shoreline monitoring post-implementation of mitigation projects.

REDESIGN SHORE PROTECTION KAWASAN INDUSTRI KENDAL (KIK)

Abrasion incidents on the coastline in the KIK area continue to occur and cause the area boundaries to decline. so that appropriate coastal protection structures are needed. The aim of this research is to carry out re-planning in the Kendal Industrial Area (KIK) in the future area boundary plan. In carrying out this research, daily wind data for the period 2017 - 2023 is needed from a nearby location, namely the Tanjung Emas Maritime Meteorological Station, Semarang. The analysis carried out includes fetch, windrose, wave calculations, building design and force calculations in shore protection construction. From the results of the windrose analysis, the dominant wave direction is northwest. Analysis of waves in the deep sea obtained a height value of 2.45 m and a wave period of 8.32 sec. Based on the calculation results, breaking waves will occur at a depth of 2.02 m. Because the building location is at a depth of 2m, where breaking waves occur, the breaking wave height is used in building planning. The coastal protection building chosen is shore protection construction or a tetrapod sea wall. Peak elevation of 4.76 meters, peak width of 3.55 meters, building base length of 22.45 meters, back slope of 1:1, arm slope of 1:2, the first type of protective layer material uses tetrapods, second and third layer using split stone pairs with 2 size combinations.

Automatic Detection and Analysis of the Shoreline Change Rate at Maravanthe Coast, India

Maravanthe Beach has been witnessing erosion due to waves caused by tidal forces, destroying vegetation, and causing enormous damage to people’s lives, livestock, and property. Hence, an attempt has been made to understand the shoreline change analysis using the automatic shoreline extraction method and determine the rate of change in terms of erosion and accretion rate before and after the construction of coastal structures during the period from 2014 to 2023. The SWAT model was applied to analyze the influence of surface runoff on shoreline changes near Maravanthe Beach for the periods 2004–2014 and 2012–2023. Also, runoff was chosen as one of the parameters for validation of the analysis. It was noticed that the shoreline stretch had experienced significant erosion prior to the construction of shore protection infrastructure. Soon after the deployment of certain shore structures, the shoreline progressed from a high erosion stretch to a low erosion stretch. This study reveals that Maravanthe Beach witnessed greater erosion during the period 2014–2018 than it did from 2019–2023 and also observed a decrease in erosion from 11% to 3% and an increase in the accretion zones from 2 to 9%.

Study on the stable behavior of the river embankment system considering climate change impacts and pressure wave

Understanding the behavior of working conditions of the embankment structural system on reinforced concrete pile foundations is very important in design, construction, operation exploitation, and use. This study assessed the adaptive performance of the Hau River landslide protection embankment in regard to climate change scenarios, specifically the impacts of more extraordinary groundwater table drawdown conditions including pressure waves. The study uses Plaxis 2D V.22 software to simulate and calculate the safety factor of the stability of landslide protection embankment on the right bank of Hau River in the area of Binh Duc Ward, Long Xuyen City, An Giang Province. Simulation. The research results on the effectiveness of shore protection works by the seawall system show that the impact of rising water levels as forecasted by climate change projections (+2.8m elevation) is still within the safe limits. Besides, the dangerous scenario of lowering water levels from the design elevation of -1.0 m (Msf = 1.114) down to the climate change water level of -1.5m elevation (Msf = 1.113)) affecting the protected shoreline also has a minor influence on the stability of the structure. Moreover, the impact of waves on the protection works, which is negligible, is also reduced by the shore protection seawall.

2D Model For Addu City Project - Wave Transformation Over Reef Flat

Van Oord DMC was awarded the Contract for the Reclamation by Dredging and Shore Protection works for land in Addu City by The Ministry of National Planning, Housing and Infrastructure of the Maldives. The Scope of Works consists of the Design and Construction of (among others) Reclamation and Shore Protection Works on various locations in the Addu City atoll. The project execution started in 2022 and has been finalized at the end of 2023. The design of the Shore Protection Works has been verified in 2022 by means of 2D physical model testing in the wave flume of DHI in Denmark. Cross-sections of shore protection works for three different reclamation areas have been tested, where this abstract will focus on 2 locations at the outside of the atoll: Maradhoo and Four Lane Link Road (4LLR). All dimensions given in this abstract are prototype values, unless otherwise specified. The length scale of the both models was selected at 1:30. The foreshore of the 2 tested cross-sections is very typical for atolls, consisting of a relatively shallow reef flat followed by a very steep slope to deep water. The modelled foreshores are presented in Figure 1. This figure also shows the locations of the wave gauges, which were placed both offshore (near the wave generator) and on top of the reef flat (in front of the structure). The tested seabed levels directly at the toe of the 4LLR and Maradhoo structures were MSL-0.70m and MSL-0.40m respectively. The target wave conditions were defined in deep water (in front of the wave generator), with design wave heights (Hm0) between 3.8m and 4.4m and 120% overload conditions. The tested peak wave periods (Tp) varied between 11.9s and 19.7s.

Muddy Waters

Coastal development did not arise from sovereign property rights to the coast or efforts to fix moving shorelines in law. Instead, it emerged from ideas of the public good and public trust that vested the protection of shores and seas in modern states. State protection supported coastal development, especially ports, in the era of steamship technology. By examining case studies from seventeenth-century to late nineteenth-century coastal India, this essay illustrates how the idea of state protection emerged through legal disputes over the obligations of littoral societies, international law, customary practices, definitions of navigable waters, accretion, and the status of subterranean or derelict land. The resultant terraqueous framework was legally plural. Nevertheless, it strengthened state claims over coastal areas and facilitated coastal development by circumscribing the boundaries of littoral societies’ claims that have traditionally relied on fishing or livelihoods tied to these waters.

A Study on Crenulate - Shaped Bays in Coastline of Sri Lanka

Various research studies have been reported in the literature investigating the crenulate-shaped bays that are frequently seen in coastlines all over the world and these coastal bays are recognized as the most stable naturally forming beaches under oblique wave attacks mostly due to swell dominant seas. Although many crenulated bays exist in Sri Lanka coastline, no considerable attention has been given so far to investigate their characteristics. The authors have studied the temporal and spatial variations of crenulated bays in many parts of the coastline of Sri Lanka using Google Earth images. Based on the detailed analysis carried out to investigate the shape of the bay profiles using empirical formulations, a hyperbolic tangent formula has been identified as the best fit for crenulated bays in the coastline of Sri Lanka. Considering various coastal sectors and monsoon seasons, different relationships have been derived between the coefficients a and b of the hyperbolic tangent formula. A relationship that has been developed co-relating the coefficient a with few coastal parameters is also discussed. Since many parts of the Sri Lanka coastline are subjected to severe erosion despite the construction of a variety of shore protection structures in traditional ways, a new approach is suggested for carrying out such work where the coastal structures will be aligned in predetermined directions depending on the coastal stretch so that stable crenulated bays will be naturally formed in between these structures, stabilizing the entire coastal stretch. This approach will be very useful in managing coastal erosion problem in the future.

Spectral analysis of oscillatory wind wave parameters in fetch-limited deep-water conditions at a small reservoir and their prediction: Case Study of the Hulín Reservoir in the Czech Republic

Abstract The dams and banks of small water reservoirs face significant erosion from wind-generated oscillatory waves. Proper design of structure height is crucial to protect such banks against erosion, considering the maximum characteristics of wind waves. Long-term measurements at the Hulín reservoir revealed that the wave spectrum aligns best with the Bretschneider type. This spectrum serves as a basis for simulating oscillatory waves and their impact on shore protection structure design. Empirical models were evaluated using wind and wave data from Hulín reservoir in the Czech Republic. The measured wind speeds attained a maximum of 8 m/s, and wave heights reached up to 15 cm. The Bretschneider (SMB) empirical formula provided the most accurate estimation of wave height (H m 0), with an average underestimate of RMSE = 0.038 m. On the other hand, Wilson revisited (WIL rev.) performed less effectively, with an average RMSE = 0.304 m. For wave period (T) estimation, Bretschneider (SMB) yielded the best results, with an average RMSE = 0.062 s. Conversely, Wilson revisited (WIL rev.) showed poorer performance, with an average underestimate of RMSE = 2.196 s. The discrepancy between the empirical formulas and measured values, particularly in underestimating H m 0, can be attributed to inaccurate determination of fetch length and wind speed.

Hydrodynamic Analysis-Based Modeling of Coastal Abrasion Prevention (Case Study: Pulau Baai Port, Bengkulu)

Pulau Baai Port, located strategically in the Indian Ocean and considered a vital maritime hub in Indonesia, grapples with persistent challenges related to abrasion and sedimentation, which negatively impact its maritime infrastructure. One of the affected components is the exposed gas pipeline installation along the port’s coastline. The sedimentation rate along Pulau Baai’s coastline is alarming, ranging from 600,000 to 800,000 m3/year, resulting in coastal abrasion at a rate of up to 20 m/year. This study focuses on three scenarios using MIKE 21, including a baseline without alternatives, shore protection alternatives, and jetty protection alternatives. A comprehensive dataset, incorporating bathymetric maps, wave patterns, current data, and sediment characteristics, supports the analysis of coastal dynamics, emphasizing the urgency for intervention. The research introduces the novelty of analyzing coastal abrasion through the exposure of underground pipelines, establishing a relationship between impacting factors such as wave height, tides, sedimentation, and coastal abrasion. Mitigation alternatives, particularly alternative model-2 with jetty protection, are recommended based on a thorough evaluation of the model performance and actual measurements. The results show that Pulau Baai’s sediment, primarily sandy, experiences substantial abrasion and coastline changes, notably in alternatives-2 and -3. The study anticipates potential sedimentation in certain sections of the subsea exposed pipelines in the absence of shore protection. The outcomes of this research provide a foundational guide for informed decision making and strategies to ensure the sustainable functionality of maritime infrastructure in Pulau Baai and similar coastal regions.

A Geomorphic Study on the Evolvement of Shore Protection Strategies in Italy: Application of MeePaSoL Software

A Geomorphic Study on the Evolvement of Shore Protection Strategies in Italy: Application of MeePaSoL Software

Experimental evaluation of water infiltration through concrete-geocell liners

In this article we study the infiltration rate and flow characteristics of water through concrete-geocell liners by experimental and analytical means. Geocells filled with concrete have been used in the construction of many hydraulic works, such as shore protections (both marine and riverine), spillways, and canal liners; these liners have been reported to offer high performance, as they are able to withstand large flow velocities, hydrodynamic effects, and environmental stresses, while still being more cost-effective than other hard-armor systems such as reinforced concrete and articulating concrete blocks (ACBs). Despite their increasing use there is no report of their hydraulic conductivity in the literature, which this paper aims to fulfil. First, an analytical solution to the problem is achieved by parting from the incompressible Navier-Stokes equations and applying reasonable assumptions to arrive at a formula that relates flow rate to pressure gradient, fluid properties, and importantly, the hydraulic aperture (the idealized gap at the concrete-geocell interface); this gap is then estimated using the ACI-209 method for the prediction of concrete shrinkage, resulting in the proposed semi-analytical method. The formulation was then evaluated experimentally by conducting hydraulic tests on full scale geocell specimens filled with concrete under conditions that are deemed representative of real case applications. The results indicate that the proposed methodology has satisfactory predictive capabilities and provides flow rate estimates in accordance with measured data.

Analysis of the stability of the Kuban river landslide slope involving the materials of landslide hazard monitoring

The article discusses the improvement of methods for calculating the landslide threat in the monitoring of landslide hazard areas on the Kuban River and the study of the possibility of their negative impact on the operated hydraulic structures. The growth of economic activity, intensive use of water resources in the Kuban River basin leads to a decrease in the bearing capacity of slopes and an increase in landslide phenomena. These processes are also observed in the basins of other anthropogenically developed rivers of the Russian Federation. Shore protection structures and their construction are justified on the basis of the limit state method in accordance with the requirements of SR 58.13330.2011. The stability of such structures should be determined by reference to the stability conditions of the entire slope taking into account all acting loads and impacts. To solve this problem it is very effective to use a complex of structures regulating the flow of the river, flow guides (dams made of selected rockfill), slope-strengthening ones, etc. Measures justifying economic activity on a landslide slope are very effective. The right slope of the Kuban River in the suburbs of Armavir, Krasnodar Krai is characterized by the fact that significant (more than 3 m) fluctuations in inter-level and flood flow of rare frequency are observed on this section of the river. Realizing anti-landslide and bank strengthening measures it is necessary to provide for both a reduction in general and local erosion of the left bank and the drainage of groundwater and surface from the anthropogenically developed area adjacent to the right slope of the river Kuban. The purpose of this research is to substantiate the stability of the right slope of the Kuban River in the vicinity of the city of Armavir, Krasnodar Krai, where initial collapses are already taking place in connection with the construction of residential buildings in the immediate vicinity of the bank and the development of general and local erosion of the right bank of the river. The calculation is carried out according to several methods for the basic and special load combinations. These calculations are necessary to substantiate landslide and bank protection measures on the right bank of the Kuban River.

Physical Modelling in Development of the Regulatory Framework for Transport Construction

Application of the physical modelling method to justify regulatory requirements for design of structures for engineering protection of transport facilities from wave action is considered using the example of three completed research and development works. The described experimental studies of interaction of waves with structures were carried out in wave basins and tanks.The objective of the research is to scientifically substantiate the requirements of regulatory documents for design of shore protection to ensure safe operation of the roadbed of railways and roads, bridge supports, and other transport structures operated under conditions of wave action on the shores of seas and lakes. In this case, the normalised parameters, depending on the hydrological (wind-wave and sea-level regimes of the water area and current), geological-morphological and lithodynamic (coastal zone dynamics) conditions are the types of protective structures used, planned and design solutions for protective hydraulic structures (location, elevations, dimensions), as well as the materials and products used for construction (including quality requirements).The experimental design part of the described studies was carried out by the method of physical (hydraulic) modelling in wave basins and tanks. Physical modelling was carried out in accordance with the theory of similarity. At the same time, a «flat problem» is solved in wave tanks, and a «spatial problem» is solved in wave basins.

Comprehensive Analysis of Extreme Meteorological Conditions for the Safety and Reliability of Floating Photovoltaic Systems: A Case on the Mediterranean Coast

In recent decades, renewable energy projects have required careful consideration of environmental factors. This study investigates the impact of a mid-latitude cyclone on planned floating photovoltaic (FPV) facilities in Antalya, Turkey, focusing on the severe thunderstorm events that brought heavy rainfall and tornadoes in January 2019. Synoptic analysis reveals a deep cut-off low over the Genoa Gulf, causing trough formation and vertical cloud development due to moisture convergence. Warm air advection pushed an unstable thunderstorm system northward along an occluded front. Using the Weather Research and Forecast (WRF) model, sensitivity analysis is conducted, highlighting regional variations in wind speeds. The model outputs are compared with observations, identifying the best configuration using statistical indicators. The Mellor–Yamada–Janjic (MYJ) planetary boundary layer (PBL) scheme and the Milbrandt microphysics scheme produced better results in the western and central regions. The model output of the best configurations is used to calculate regional wave characteristics with a modified Shore Protection Manual (SPM) method for water reservoirs. These findings offer invaluable insights for future FPV projects, providing a better understanding of how to address challenges posed by extreme weather conditions and how to enhance system safety and reliability.

Experimental investigation on the hydrodynamic performance of a pile-supported OWC-type breakwater

The present study considers the design optimisation of an Oscillating Water Column (OWC) incorporated into a pile-supported breakwater structure. This has been achieved by performing a substantial number of scaled physical model tests and a methodical variation of key device parameters within multiple configurations. The key aspects that have been investigated include: (a) the geometric characteristics of the breakwater structure, (b) the pneumatic efficiency of the OWC, (c) the geometry of the OWC chamber and (d) the relative position of the OWC chamber within the breakwater. The present work considers (monochromatic) regular waves of varying steepness and effective water depth as incident wave conditions. The efficiency of the designed structure in terms of shore protection capacity and wave energy extraction was assessed by quantifying relevant transmission coefficients and the power output metrics. This has been achieved by using a combination of collocated and complementary measuring devices, such as arrays of wave gauges, pressure transducers and a high-definition video camera. The study concluded that systematic refinement of the geometrical parameters can substantially enhance the overall hydrodynamic efficiency of a pile-supported OWC breakwater. Additionally, it was found that a configuration featuring a chamber positioned in front of the breakwater, with a relative chamber breadth of 0.67, outperforms wider breadth configurations in terms of both energy extraction efficiency and reduction of the transmission coefficient. Taken together, the present study provides an in-depth analysis of the effects of key design parameters of a breakwater-integrated OWC, its efficiency and shore protection potential.