Coastal Protection Strategies Research Articles

The impact of a storm on the microtidal flat in the Yellow River Delta

Strong hydrodynamic forces generated by storms are key in shaping coastal tidal flats. Most tidal flats achieve equilibrium by adapting to hydrodynamic conditions and sediment inputs. However, high-energy wave activity during storms disrupts this equilibrium, causing rapid and significant changes, particularly in tidal flats, especially in microtidal flats, which are characterized by low tidal ranges. In this study, we conducted an 11-d field campaign on a microtidal flat in the Yellow River Delta (YRD), capturing data during both stormy and calm weather conditions. We measured tidal currents, wave activity, suspended sediment concentrations and sediment grain sizes. The results demonstrated that the tidal flat maintained equilibrium under calm conditions, with minimal fluctuations in bed level (within ±2 mm). Contrastingly, severe erosion and sediment removal during the storm significantly altered the equilibrium of the area. The storm-induced high shear stresses, ranging from 1.02 to 1.48 , along with alongshore sediment transport, resulted in an elevation change of -10 mm. Furthermore, the subsequent bed level recovery was minimal and insufficient to offset the erosion. Compared to that of the mesotidal and macrotidal flats, post-storm recovery on microtidal flats was limited due to shorter inundation periods and weaker hydrodynamic forces. Therefore, frequent storms may lead to continuous shoreline retreat on microtidal coasts. Conclusively, the present findings underscore the significant impact of storm-induced erosion on the evolutionary processes of microtidal flats and suggest that greater attention should be given to protecting these areas during storms in the Yellow River Delta. The insights can guide the development of more effective coastal protection strategies, highlighting the need for enhanced measures to mitigate erosion and promote resilience in microtidal regions.

Challenges and opportunities for implementing nature-based coastal protection in an urbanised coastal city based on public perceptions

There has been an increase in recognition of the benefits of employing nature-based coastal protection strategies to adapt to the impacts of climate change (e.g., increased storminess, sea-level rise). To enable broader use of nature-based methods, coastal managers and policymakers need to consider the placement and social acceptance of any methods considered. Most published spatial planning models for nature-based coastal protection currently do not utilise social data during site selection. We conducted a public survey of 452 respondents from Singapore, a highly urbanised coastal city-state, to assess Singaporean's perceptions of climate change impacts on coastal areas and their support of nature-based coastal protection. We also assessed the respondents willingness to accept trade-offs for the prioritisation of nature-based coastal protection and subsequently spatially mapped them. The results showed a high awareness of the potential impacts of climate change on coastal areas. Nature-based coastal protection was highly supported as the associated benefits, such as protection of wildlife and their habitats and climate change reduction, were aligned with public values of coastal areas. However, nature-based coastal protection may not be prioritised over human-made structures due to the perception that they are less effective, and respondents may not be willing to undergo 1) replacement of their favourite coastal area, 2) increased taxes, and 3) relocation, for their prioritisation. Through spatially mapping the relevant trade-offs, we found that only 11.1% of coastal areas had moderate or high likelihood of social barriers to nature-based coastal protection, highlighting their potential in Singapore. These findings underscore the importance of incorporating social factors in government land use planning decisions.

Managing a potential conflict between the protection of geological sites and the need to safeguard essential road infrastructure: the Coverack North Coast Protection Scheme and palaeo-Moho in Cornwall, UK

In alignment with the Cornwall & Isles of Scilly Shoreline Management Plan (SMP2), adopted by Cornwall Council, the Coverack North Coast Protection Scheme comprised the construction of a circa 125m long rock armour revetment, and 55m long retaining wall, at Coverack Cove on the Lizard peninsula in Cornwall, UK. This was to prevent sea erosion impacting vehicle access via the B3294, the main public highway into Coverack. The site of the proposed works on Coverack Beach is part of a Natural England designated Site of Special Scientific Interest (SSSI) for its geology, specifically the exposure on the foreshore of an almost continuous cross section of a palaeo-Moho, the former boundary between the earth's crust and underlying mantle. Following a period of consultation, a set of management proposals and mitigation measures were agreed with Natural England and Cornwall Council to protect and offset the impact of the proposed works on the SSSI asset. It is sometimes difficult to reconcile the issue of protecting communities from coastal erosion and ensuring the protection of geological assets. This can be mitigated if a balanced approach is adopted, and the work is sensitively managed to offset the impact of coastal protection schemes such of this.

Hydrodynamic Performance Assessment of Emerged, Alternatively Submerged and Submerged Semicircular Breakwater: An Experimental and Computational Study

Coastal protection structures are essential defenses against wave energy, safeguarding coastal communities. This study aims to refine coastal protection strategies by employing a semicircular breakwater (SBW) model. Through a combination of physical and computational models, the hydrodynamic properties of the SBW under regular wave conditions were thoroughly examined. The primary objectives included delineating the hydrodynamic characteristics of SBWs, developing a computational model to validate experimental findings. Hydrodynamic characteristics of the SBW model were scrutinized across various wave conditions. Experimental testing in a wave flume covered a range of relative water depths (d/h) from 0.667 to 1.667, wave steepness (Hi/L) spanning 0.02 to 0.06 and wave periods ranging from 0.8 to 2.5 s. Notably, analysis of an emerged SBW with d/h = 0.667 revealed superior wave reflection, while an alternative submerged SBW with d/h = 1.000 showed the highest energy loss. These findings are further corroborated by the validation of computational models against experimental outcomes for d/h = 0.667, 1.000, 1.333 and 1.667. Moreover, the investigation of forces revealed an inverse correlation between horizontal forces and wave height, while vertical forces showed nuanced variations, including a slightly decreasing average vertical force with greater relative wave period (B/L) for different immersion scenarios.

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.

Seagrass decline weakens sediment organic carbon stability

Seagrass meadows are globally recognized as critical natural carbon sinks, commonly known as ‘blue carbon’. However, seagrass decline attributed to escalating human activities and climate change, significantly influences their carbon sequestration capacity. A key aspect in comprehending the impact of seagrass decline on carbon sequestration is understanding how degradation affects the stored blue carbon, primarily consisting of sediment organic carbon (SOC). While it is widely acknowledged that seagrass decline affects the input of organic carbon, little is known about its impact on SOC pool stability. To address this knowledge, we examined variations in total SOC and recalcitrant SOC (RSOC) at a depth of 15 cm in nine seagrass meadows located on the coast of Southern China. Our findings revealed that the ratio of RSOC to SOC (RSOC/SOC) ranged from 27 % to 91 % in the seagrass meadows, and the RSOC/SOC increased slightly with depth. Comparing different seagrass species, we observed that SOC and RSOC stocks were 1.94 and 3.19-fold higher under Halophila beccarii and Halophila ovalis meadows compared to Thalassia hemprichii and Enhalus acoroides meadows. Redundancy and correlation analyses indicated that SOC and RSOC content and stock, as well as the RSOC/SOC ratio, decreased with declining seagrass shoot density, biomass, and coverage. This implies that the loss of seagrass, caused by human activities and climate change, results in a reduction in carbon sequestration stability. Further, the RSOC decreased by 15 %, 29 %, and 40 % under unvegetated areas compared to adjacent Halophila spp., T. hemprichii and E. acoroides meadows, respectively. Given the anticipated acceleration of seagrass decline due to climate change and increasing coastal development, our study provides timely information for developing coastal carbon protection strategies. These strategies should focus on preserving seagrass and restoring damaged seagrass meadows, to maximize their carbon sequestration capacity.

Semicircular Coastal Defence Structures: Impact of Gap Spacing on Shoreline Dynamics during Storm Events

Coastal erosion poses significant challenges to shoreline management, exacerbated by rising sea levels and changing climate patterns. This study investigates the influence of gap spacing between semicircular coastal defence structures on shoreline dynamics during storm events. The innovative design of these structures aims to induce a drift reversal of prevalent sediment transport while avoiding interruption of alongshore sediment drift, thus protecting the beach. Three different gap spacings, ranging from 152 m to 304 m, were analysed using the XBeach numerical model, focusing on storm morphodynamic behaviour. Methodologically, hydrodynamic and morphodynamic analyses were conducted to understand variations in significant wave heights adjacent to the structures, in accretion and erosion volumes, and changes in bed level under storm conditions. The study aims to elucidate the complex interaction between engineered coastal protection solutions and natural coastal processes, providing practical insights for coastal management practices. Results indicate that installing semicircular coastal defence structures influences sediment dynamics during storm events, effectively protecting stretches of the coast at risk. Optimal gap spacing between structures is crucial to mitigating coastal erosion and enhancing sediment accumulation, offering a sustainable shoreline protection approach. The findings underscore the importance of balanced location selection to optimize protection benefits while minimizing adverse morphological effects. Overall, this research contributes to advancing knowledge of hydro-morphological phenomena essential for effective coastal engineering and informs the design and implementation of more sustainable coastal protection strategies in the face of increasing coastal erosion and sea level rise challenges.

Large-Scale Test Of Extreme Hydrodynamic Conditions Over Coastal Salt Marshes

Hard coastal structures such as dikes covered with asphalt or placed block revetments have been widely used in the past for coastal protection in densely populated deltas around the world. Nonetheless, in recent years the effectiveness of hard structures has been questioned in light of the inevitable effects of climate change and their static nature. Decades of research on how salt marshes can play a role within a comprehensive coastal protection scheme suggest that these low environmental impact structures (Maza et al., 2015) might have the capability of dissipating wave energy and hence be technically and formally considered within hybrid coastal erosion and flood protection systems (Borsje et al., 2011). However, only very few studies investigated wave attenuation by real salt marsh vegetation in large-scale laboratories (Ghodoosipour et al., 2022; Maza et al., 2015; Möller et al., 2014) and none of them addressed extreme hydrodynamic design conditions in terms of wave energy and water levels. As a result of this knowledge gap, salt marshes in The Netherlands and all around the world have never been formally considered within the coastal flood protection systems and the underlying risk assessment. With this contribution our aim is to provide an overview of the first worldwide large-scale test focused on the interaction between a salt marsh (i.e. vegetation and shallow foreshore) and extreme hydrodynamic conditions, the adopted measurement techniques and the preliminary results in terms of wave damping, erosion and removed biomass.

Seasonal Variation Of Wave Attenuation Capacity Of Canadian Saltmarsh Vegetation

Nature-based Solutions (NbS) for coastal protection have been widely recognized as sustainable, economical, and eco-friendly alternatives to conventional grey structures, particularly under the threat of climate change (Temmerman et al., 2013). Living shorelines are a form of NbS, which incorporate natural elements (such as saltmarshes) that provide flood and erosion risk management benefits. Climate change impacts, such as rising sea levels and reducing sea-ice cover (Savard et al., 2016), are increasingly motivating communities in Canada to consider incorporating living shorelines in coastal protection schemes. The efficacy of wave energy dissipation by vegetation depends on both hydrodynamic conditions and plant characteristics. However, plant parameters, such as standing biomass exhibit seasonal fluctuations, leading to corresponding variations in attenuation capacity (Schulze et al., 2019). Hence, the design of NbS utilizing saltmarsh vegetation must account for seasonal variations to ensure sustained efficacy, especially within the context of Canadian regional climates, which are typically characterized by extended, stormy winters and shorter summer seasons. Few studies have quantified wave attenuation by real saltmarsh vegetation in large-scale laboratory facilities (Möller et al., 2014; Maza et al., 2015; Ghodoosipour et al., 2022), particularly for species native to the east coast of Canada. There is a knowledge gap on how seasonality affects wave attenuation by saltmarsh vegetation and how attenuation varies from the lower marsh to the higher marsh depending on species-specific plant traits. Research is needed to bridge this gap and develop technical guidance for the design of performant living shorelines in Canada.

Evaluation of Shoreline Alteration Along theJagatsinghpur District Coast, India (1990–2020) using DSAS

This scientific investigation provides valuable insights into the dynamics of shoreline alteration in the Jagatsinghpur district coast, facilitating informed decision-making for implementing coastal protection strategies. This study presents a comprehensive assessment of shoreline alteration along the 55.045 km stretch of the Jagatsinghpur district coast in India from 1990 to 2020. Landsat 5 TM and 8 OLI satellite image data were used for the analysis. The quantification of erosion and deposition shoreline change rates are computed through a semi-automated approach employing four statistical methods SCE, NSM, EPR, and LLR in the Digital Shoreline Analysis System (DSAS). The coastline was divided into four zones at the tehsil level, resulting in the generation of 5149 transects, categorized as Paradip tehsil-I, Abhyachandpur tehsil-II, Ersama tehsil-III, and Balikud tehsil-IV. The analysis revealed significant erosion in specific areas, including Paradip town in Zone I, Nuagan in Zone II, Zone III, and Kusupur in Zone IV. The decision matrix showed an urgent need for erosion rectification in specific regions. The results indicate the necessity of implementing coastal protection measures in Zone III, B, and D subregions in Zone I and D and F subregions in Zone II. Meanwhile, in Zone IV, subregions A and B necessitate attention.

Evolution Modeling and Protection Scheme for Tidal Flats Under Natural Change and Human Pressure, Central Jiangsu Coast

AbstractAmidst escalating global changes and heightened human activities, tidal flats worldwide are facing a transition from accretion to erosion. In order to quantify the growth pattern of tidal flats and its response to changes in multiple external driving factors, here we established a geometric model, in combination with field surveys, to study the historical behavior (1127–1990) and future trends (2100) of a typical tidal flat system on the Jiangsu coast, China. The results indicate that sediment supply and relative sea level change determine the accretion‐erosion status and the eventual morphological pattern of the tidal flat. If these two factors remain stable and sediment supply can compensate for the increase in sediment accommodation space caused by sea level change, the tidal flat will continue to accrete until its growth limit is reached. Otherwise, tidal flats will face erosion risk, which can be further enhanced by localized land subsidence. Furthermore, changes in the coastal profile show a trend of progressive retreating, with the lower part of intertidal zone being eroded more rapidly than its upper part. This demonstrates that the sediment supply has been reduced to such a level that the present “in‐transition” evolution pattern of central Jiangsu coast will soon be replaced by severe inundation and erosion. Hence, we advocate for a comprehensive, multi‐tiered coastal protection strategy focusing on wave suppression, enhancement of sediment retention, and increased storm resistance. This strategy underscores fundamental underlying mechanisms of the accretion‐erosion transition, which is crucial for the future safeguarding of coastal wetlands globally.

Eko-kejuruteraan dalam Penerapan Pertahanan Pantai berasaskan Alam Semula Jadi

Climate change increases the threat of erosion and flooding along coastlines around the world. Engineering technologies are response to protecting coastal communities and related infrastructure becoming increasingly unsustainable in economic and ecological contexts. This issue has led proposal to restore natural habitats, such as sand shoals, saltwater swamp areas, mangroves, seaweed, coral reefs, and shellfish, to provide coastal protection in lieu of or to complement artificial structures. Often coastal management is faced with eroded coastal problems which require decision on the most suitable mitigation option to implement. In this short review article, the application of eco-engineering in nature-based coastal defense is discussed. The obstacle in taking on the naturebased coastal defences is because of the rigorous assessment of their effectiveness compared to artificial protection structures. The assessment of the latest evidence for the effectiveness of nature-based beach protection versus artificial beach protection and future research needs are discussed in this review. Future projects should evaluate the habitat created or restored for coastal defence for its cost-effectiveness compared to artificial structures under the same environmental conditions. A cost-benefit analysis should consider all ecosystem services provided by nature-based or artificial structures in addition to coastal protection. Research among scientists, coastal managers, and engineers are needed to facilitate the experiments needed to test the value of this coastal protection scheme and to support its use as an alternative to artificial structures. This research is urgently needed because the rapidly changing climate requires new and innovative solutions to reduce the vulnerability of coastal communities.

Integrating marine functional zoning in coastal planning: Lessons from the Xiasha Beach Resort case study

Marine spatial planning (MSP) represents a critical tool for the worldwide design of coastal development and protection strategies. China, as one of the pioneers in establishing comprehensive MSP policies, has created a well-developed marine planning structure—known as the “multi-rule-in-one"—with Marine Functional Zoning (MFZ) serving as a cornerstone for the country's coastal economic and environmental development. Despite its significance, limited studies have presented the practical application of MSP/MFZ policies upon tourism exploitation in coastal regions. This paper fills this research gap by thoroughly examining China's marine planning structure, the implementation of provincial MFZ policy, and the operational mechanisms of these strategies. The analysis focuses on the Xiasha Beach Resort, a case study exemplifying the coordinated efforts required among governments, scientists, and the public for the successful implementation of MFZ policy. Findings from the Xiasha Beach Resort highlight the importance of robust tourist market management, a shift from hard seawall structures towards more eco-friendly alternatives, and a high degree of collaboration among key stakeholders. Furthermore, the study emphasizes the importance of ecosystem-based restoration technology that maintains the integrity of the beach-dune system, fosters diverse vegetation, and encourages adaptive measures such as environmental capacity control. The sustainability of the MSP approach hinges on wide and diverse public participation, as national MSP policies foster trust, credit, and feedback from local citizens, promoting necessary policy adjustments. In conclusion, this study offers valuable insights for domestic and international regions seeking to harmonize MSP operations to achieve high-quality coastal economic development and environmental protection targets.

Combined effects of aquifer heterogeneity and subsurface dam on nitrate contamination in coastal aquifers

Subsurface dams are effective for seawater intrusion mitigation, yet they can cause upstream nitrate accumulation. This research examines the interplay between subsurface dam construction and aquifer layering on nitrate pollution in coastal settings, employing numerical models to simulate density-driven flow and reactive transport. The study reveals that while subsurface dams are adept at curbing seawater intrusion, they inadvertently broaden the nitrate accumulation zone, especially when a low-K layer is present. Heterogeneous aquifers see more pronounced nitrate accumulation from subsurface dams. This effect is pronounced as it influences dissolved organic carbon dynamics, with a notable retreat inland correlating with the expansion of the nitrate pollution plume. A critical finding is that controlling seawater intrusion via dam height adjustment within the Effective Damming Region effectively reduces nitrate levels and bolsters freshwater output. However, exceeding the critical threshold—where the dam surpasses the low-K layer's bottom—results in a substantial shift in nitrate concentration, underscoring the need for precise dam height calibration to avoid aggravating nitrate pollution. This study's innovative contribution lies in its quantification of the nuanced effects of subsurface dams in stratified aquifers, providing an empirical basis for dam design that considers the layered complexities of coastal aquifers. The insights offer a valuable framework for managing nitrate contamination, thus informing sustainable coastal groundwater management and protection strategies.

Shallow Coastal Carbonate Sediment Mapping for Biomimetics MICP, Case Study of Indonesia Beachrock, Yogyakarta

The nomenclature for beachrock sedimentary has been in scientific discussions prior to the notable methodology of sustainable cementitious binding material based on microbially induced calcium carbonate (MICP). Typically, coastal erosion mitigation involves modifying surface conditions using materials like concrete, among other materials. This study aims to challenge the conventional practice by evaluating the feasibility of expeditiously constructing artificial beachrock utilizing natural components (e.g., microbes, sand, shells, coral fragments, seaweed, etc.) and propose it as an innovative coastal protection strategy. The primary focus of this research is to characterize the Java South coast, specifically Parangtritis Beach and Krakal-Sadranan Beach, where beachrock formations are present. Subsequent investigations were conducted to (i) identify occurrences of beachrock deposits in Krakal-Sadranan, Yogyakarta, and (ii) develop cementation method based on ureolytic bacteria derived from naturally formed beachrock as an alternative technique for stabilizing sandy coastal environments. The experiment employed bacteria isolated from the Yogyakarta coast (Pseudoalteromonas tetradonis). The outcomes revealed that the sample treated with a gradually injected cementation solution achieved an approximate strength of 10 MPa after a 14-day treatment.

Monitoring of a Coastal Protection Scheme through Satellite Remote Sensing: A Case Study in Ghana

Earth observation can provide managers with valuable information on ongoing coastal processes and major trends in coastline evolution, especially in data-poor regions. This paper examines the use of optical satellite images in the mapping of the changes in shoreline position before, during, and after the implementation of a protection scheme. The aim of this paper is twofold: (i) to demonstrate the potential of satellite imagery as an effective, robust, and low-cost tool to remotely monitor the effectiveness of protective structures based on a large-scale case study in West Africa; and (ii) to compile lessons learned from this case study that can be used in the design of future interventions. The analysis shows that before the implementation of the protection scheme, the coastal sector was retreating at a rate of −1.6 m/year, which is in line with the average retreat rates reported in other studies for the region. After project implementation, this trend reversed into shoreline accretion at a rate of +1.0 m/year, locally experiencing positive and negative oscillations in the short term. Furthermore, the shoreline-extracted positions proved useful in assessing the impact of differences in the groynes’ permeability with respect to temporary leeside erosion. Finally, it is recommended to continue this monitoring to assess long-term trends.

Regional assessment of extreme sea levels and associated coastal flooding along the German Baltic Sea coast

Abstract. Among the Baltic Sea littoral states, Germany is anticipated to endure considerable damage as a result of increased coastal flooding due to sea-level rise (SLR). Consequently, there is a growing demand for flood risk assessments, particularly at regional scales, which will improve the understanding of the impacts of SLR and assist adaptation planning. Existing studies on coastal flooding along the German Baltic Sea coast either use state-of-the-art hydrodynamic models but cover only a small fraction of the study region or assess potential flood extents for the entire region but rely on global topographic data sources and apply the simplified bathtub approach. In addition, the validation of produced flood extents is often not provided. Here we apply a fully validated hydrodynamic modelling framework covering the German Baltic Sea coast that includes the height of natural and anthropogenic coastal protection structures in the study region. Using this modelling framework, we extrapolate spatially explicit 200-year return water levels, which align with the design standard of state embankments in the region, and simulate associated coastal flooding. Specifically, we explore (1) how flood extents may change until 2100 if dike heights are not upgraded, by applying two high-end SLR scenarios (1 and 1.5 m); (2) hotspots of coastal flooding; and (3) the use of SAR imagery for validating the simulated flood extents. Our results confirm that the German Baltic coast is exposed to coastal flooding, with flood extent varying between 217 and 1016 km2 for the 200-year event and a 200-year event with 1.5 m SLR, respectively. Most of the flooding occurs in the federal state of Mecklenburg-Western Pomerania, while extreme water levels are generally higher in Schleswig-Holstein. Our results emphasise the importance of current plans to update coastal protection schemes along the German Baltic Sea coast over the 21st century in order to prevent large-scale damage in the future.

THE SELECTION AND DESIGN OF VEGETATED DUNES AS PREFERRED MAIN COASTAL PROTECTION SYSTEM FOR BEIRA, MOZAMBIQUE

The coastal city of Beira is vulnerable to cyclones, storm surges, sea-level rise and floods from intensive rainfall events because of its low-lying situation. Cyclone Idai in 2019 has proven this again. A significant improvement of the coastal protection scheme is needed to provide sufficient protection for Beira to protect from hazards from sea and climate change for decades to come. The coastal protection infrastructure is to be integrated into the urban and natural environment of Beira, whilst seeking socio-economic, environmental and urban synergy. In this context, we performed an extensive flood and erosion risk assessment, feasibility study and design, environmental and social scoping study and set up an implementation strategy for the selected preferred alternative and priority measures. This included an intensive stakeholder engagement process throughout the project (2020-2022).

NEW INSIGHTS ON USING SCALED MARSH PLANT SURROGATES FOR WAVE ATTENUATION

It has been widely demonstrated in literature that coastal marshes provide positive ecosystem services related to coastal protection, including wave attenuation, storm surge reduction, and erosion prevention (Moller et al., 2014; Wang et al., 2021; Paul and Kerpen, 2021). Physical modelling presents a useful tool for investigating the coastal protection function provided by marsh vegetation in a controlled, repeatable environment, to inform design of nature-based coastal protection strategies, or “nature-based solutions” (NBS). To date, physical modelling studies have been used to investigate the influence of plant biophysical parameters (stem width, stem height, stem flexibility) and hydrodynamic conditions on wave attenuation (e.g., Augustin et al., 2009; Anderson and Smith, 2014; Moller et al., 2014; Ozeren et al., 2014; van Veelen et al., 2020). Such studies have predominantly used surrogate vegetation due to the logistical challenges and facility requirements associated with live plant experiments. Furthermore, most studies have been performed at or near full-scale to reduce uncertainties and scale effects associated with downscaling vegetation, particularly where Reynolds number similarity cannot be preserved (Blackmar et al., 2014). To address existing knowledge gaps related to physical modelling of marsh vegetation at small-scale, experiments were conducted in a 63 m long by 1.22 m wide wave flume at the National Research Council of Canada’s Ocean, Coastal and River Engineering Research Centre, Ottawa, in collaboration with the University of Ottawa and the Institut National de la Recherche Scientifique, Quebec City.

SATELLITE-DERIVED SHORELINE DYNAMICS AT THE GERMAN BALTIC SEA

Dunes play a central role in the coastal protection strategy of the German part of the Baltic Sea coastline in the state of Mecklenburg Western Pomerania (MWP). Considering the sea level rise and the limited supply of sand a closer inspection of the sand nourishment strategy and its impact on the regional shoreline of MWP is needed. Data availability on the shoreline development is sparse and only recently have the authorities (StALU) in MWP started to increase the temporal and spatial resolution of measurements (StALU 2009). The Google Earth Engine (Gorelick et al. 2017) has facilitated the possibility to investigate shorelines at the planetary scale with freely available satellite images spanning more than 30 years. Luijendijk et al. (2018) and Bishop-Taylor et al. (2021) have demonstrated the need and feasibility of long-term time series that depict the shoreline development over large spatial scales. We present the results from the remote sensing of the shoreline development at the German Baltic Sea utilizing three decades of satellite images.