Showing papers on "Shore published in 2019"

Sbeach, Numerical Model for Simulating Storm-Induced Beach Change: Report 1: Empirical Foundation and Model Development

Abstract: : A two-dimensional numerical model is presented for calculating dune and beach erosion produced by storm waves and water levels. The empirically based model was first developed from a large data set of net cross-shore sand transport rates and geomorphic change observed in large wave tanks, then verified using high-quality field data. The aim is to reproduce macroscale features of the beach profile, with focus on the formation and movement of longshore bars. The ultimate goal is prediction of storm-induced beach erosion and post-storm recovery. Bars are simulated satisfactorily, but berm processes are less well reproduced, due in part to a lack of data for defining accretionary wave and profile processes. A new criterion is developed for predicting erosion and accretion, and the model uses this criterion to calculate net sand transport rates in four regions of the nearshore extending from deep water to the limit of wave runup. Wave height and setup across the profile are calculated to obtain the net cross-shore sand transport rate. The model is driven by engineering data, with main inputs of time series of wave height and period in deep water, time series of water level, median beach grain size, and initial profile shape. Comprehensive sensitivity testing is performed, and example applications are made to evaluate the response of the profile to the presence of a vertical seawall and behavior of different beach fill cross sections in adjustment to normal and storm wave action. Keywords: Accretion; Cross shore sand transport; Dune erosion; Longshore bars.

Shoreline change detection using DSAS technique: Case of North Sinai coast, Egypt

Abstract: This study focuses on the shoreline change detection along the North Sinai coast in Egypt using geographic information system and digital shoreline analysis system (DSAS) during the elapsed period ...

High-temporal-resolution water level and storage change data sets for lakes on the Tibetan Plateau during 2000–2017 using multiple altimetric missions and Landsat-derived lake shoreline positions

Abstract: . The Tibetan Plateau (TP), known as Asia's water tower, is quite sensitive to climate change, which is reflected by changes in hydrologic state variables such as lake water storage. Given the extremely limited ground observations on the TP due to the harsh environment and complex terrain, we exploited multiple altimetric missions and Landsat satellite data to create high-temporal-resolution lake water level and storage change time series at weekly to monthly timescales for 52 large lakes (50 lakes larger than 150 km 2 and 2 lakes larger than 100 km 2 ) on the TP during 2000–2017. The data sets are available online at https://doi.org/10.1594/PANGAEA.898411 (Li et al., 2019). With Landsat archives and altimetry data, we developed water levels from lake shoreline positions (i.e., Landsat-derived water levels) that cover the study period and serve as an ideal reference for merging multisource lake water levels with systematic biases being removed. To validate the Landsat-derived water levels, field experiments were carried out in two typical lakes, and theoretical uncertainty analysis was performed based on high-resolution optical images (0.8 m) as well. The RMSE of the Landsat-derived water levels is 0.11 m compared with the in situ measurements, consistent with the magnitude from theoretical analysis (0.1–0.2 m). The accuracy of the Landsat-derived water levels that can be derived in relatively small lakes is comparable with most altimetry data. The resulting merged Landsat-derived and altimetric lake water levels can provide accurate information on multiyear and short-term monitoring of lake water levels and storage changes on the TP, and critical information on lake overflow flood monitoring and prediction as the expansion of some TP lakes becomes a serious threat to surrounding residents and infrastructure.

Requirements for a Coastal Hazards Observing System

Abstract: Coastal zones are highly dynamical systems affected by a variety of natural and anthropogenic forcing factors that include sea level rise, extreme events, local oceanic and atmospheric processes, ground subsidence, etc. However, so far, they remain poorly monitored on a global scale. To better understand changes affecting world coastal zones and to provide crucial information to decision-makers involved in adaptation to and mitigation of environmental risks, coastal observations of various types need to be collected and analyzed. In this white paper, we first discuss the main forcing agents acting on coastal regions (e.g., sea level, winds, waves and currents, river runoff, sediment supply and transport, vertical land motions, land use) and the induced coastal response (e.g., shoreline position, estuaries morphology, land topography at the land-sea interface and coastal bathymetry). We identify a number of space-based observational needs that have to be addressed in the near future to understand coastal zone evolution. Among these, improved monitoring of coastal sea level by satellite altimetry techniques is recognized as high priority. Classical altimeter data in the coastal zone are adversely affected by land contamination with degraded range and geophysical corrections. However, recent progress in coastal altimetry data processing and multisensor data synergy, offers new perspective to measure sea level change very close to the coast. This issue is discussed in much detail in this paper, including the development of a global coastal sea-level and sea state climate record with mission consistent coastal processing and products dedicated to coastal regimes. Finally, we present a new promising technology based on the use of Signals of Opportunity (SoOp), i.e., communication satellite transmissions that are reutilized as illumination sources in a bistatic radar configuration, for measuring coastal sea level. Since SoOp technology requires only receiver technology to be placed in orbit, small satellite platforms could be used, enabling a constellation to achieve high spatio-temporal resolutions of sea level in coastal zones.

Analysis of generation and arrival time of landslide tsunami to Palu City due to the 2018 Sulawesi earthquake

Abstract: Tsunami waves severely damaged the densely populated coast of Palu City immediately after the 2018 Mw 7.5 Sulawesi earthquake. Among the several tsunami waves that arrived to the city, the two initial waveforms were most likely generated by a landslide at the south-western shore of Palu Bay, about 5 km away from one of the city’s shopping malls. The authors accurately identified the arrival time and direction of the waves by comparing multiple videos taken by a pilot from the cockpit of a plane and local people who witnessed waves approaching the coast. Although the authors’ bathymetric survey only covered a limited area of 0.78 km2, it was found that about 3.2 million m3 of mass disappeared from it, causing a maximum decrease in the seabed elevation of 40 m. A landslide scarp up to 5 m height was also investigated in the southwestern shore of the bay, which seems to be relatively minor compared to the submarine mass failure. Visible clue for liquefaction was not observed at this particular site. A simplified numerical model suggests that the landslide tsunami propagated as an edge wave and split into two separate waves due to the presence of an underwater shallow area just north of Palu City. Both waves arrived to the coast of this city within several minutes: one from North-West and the other from the North. Three major waves were witnessed by residents, who felt horizontal and vertical ground movements and heard the sound of an explosion just after the earthquake. Wave splash exceeded the height of trees on the beach. Given the results, the authors conclude that any modern early warning system is unlikely to work well against such short-warning time tsunamis, and thus, it is necessary for disaster risk managers to consider a way to help people quickly become aware of the potential disaster and evacuate.

Mangroves and shoreline erosion in the Mekong River delta, Viet Nam

Abstract: The question of the rampant erosion of the shorelines rimming the Mekong River delta has assumed increasing importance over the last few years. Among issues pertinent to this question is how it is related to mangroves. Using high-resolution satellite images, we compared the width of the mangrove belt fringing the shoreline in 2012 to shoreline change (advance, retreat) between 2003 and 2012 for 3687 cross-shore transects, spaced 100 m apart, and thus covering nearly 370 km of delta shoreline bearing mangroves. The results show no significant relationships. We infer from this that, once erosion sets in following sustained deficient mud supply to the coast, the rate of shoreline change is independent of the width of the mangrove belt. Numerous studies have shown that: (1) mangroves promote coastal accretion where fine-grained sediment supply is adequate, (2) a large and healthy belt of fringing mangroves can efficiently protect a shoreline by inducing more efficient dissipation of wave energy than a narrower fringe, and (3) mangrove removal contributes to the aggravation of ongoing shoreline erosion. We fully concur, but draw attention to the fact that mangroves cannot accomplish their land-building and coastal protection roles under conditions of a failing sediment supply and prevailing erosion. Ignoring these overarching conditions implies that high expectations from mangroves in protecting and/or stabilizing the Mekong delta shoreline, and eroding shorelines elsewhere, will meet with disappointment. Among these false expectations are: (1) a large and healthy mangrove fringe is sufficient to stabilize the (eroding) shoreline, (2) a reduction in the width of a large mangrove fringe to the benefit of other activities, such as shrimp-farming, is not deleterious to the shoreline position, and (3) the effects of human-induced reductions in sediment supply to the coast can be offset by a large belt of fringing mangroves.

Response of the Bight of Benin (Gulf of Guinea, West Africa) coastline to anthropogenic and natural forcing, Part 2 : sources and patterns of sediment supply, sediment cells, and recent shoreline change

Abstract: The Bight of Benin in the Gulf of Guinea, West Africa, forms an embayment between the Volta River delta in the west (Ghana) and the Niger River delta (Nigeria) in the east. The bight coast comprises sandy beaches backed by Holocene beach-ridge barriers. Incident swell waves, beachface gradient and the unidirectional longshore sand transport from west to east are intimately linked, generating a classic example of a strongly wave-dominated drift-aligned coast. The stability of this coast, which hosts several major cities in addition to three large international deepwater ports, has been strongly affected by human activities. We analyzed shoreline mobility and coastal area change over the period 1990–2015. Our results show how the stability of this coast has been strongly affected by the three ports therein, and by natural and human-altered shoreline dynamics related to the Volta River delta and to distributaries at the northwestern flank of the Niger delta. The combination of these factors has impacted alongshore sediment redistribution by segmenting the previously unrestrained longshore transport of sand that prevailed along this open coast. The result is a mixture of natural and artificial sediment cells increasingly dominated by shoreline stretches subject to erosion, endangering parts of the rapidly expanding port cities of Lome (Togo), Cotonou (Benin) and Lagos (Nigeria), coastal roads and infrastructure, and numerous villages. Post-2000, the entire bight shoreline has undergone a significant decrease in accretion, which is here attributed to an overall diminution of sand supply via the longshore transport system. We attribute this diminution to the progressive depletion of sand-sized bedload supplied to the coast through the main Volta river channel downstream of the Akosombo dam, built between 1961 and 1965. Sand mining to cater for urban construction in Lome, Cotonou and Lagos has also contributed locally to beach sediment budget depletion. Although alongshore sediment supply from the Volta River has been the dominant source of sand for the stability or progradation of the Bight of Benin coast, potential sand supply from the shoreface, and the future impacts of sea-level rise on this increasingly vulnerable coast are also important. The continued operation of the three ports and of existing river dams, and sea-level rise, will lead to sustained shoreline erosion along the Bight of Benin in the coming decades.

Response of long- to short-term changes of the Puri coastline of Odisha (India) to natural and anthropogenic factors: a remote sensing and statistical assessment

Abstract: The coastal regions of India are densely populated and most biological productive ecosystems which are threatened by erosion, natural disaster, and anthropogenic interferences. These threats have made priority in appraisal of shoreline dynamicity as part of sustainable management of coastal zones. The present study assessed the long- to short-term dynamicity of shoreline positions along the coast of Puri district, Odisha, India, during the past 25 years (1990–2015) using open-source multi-temporal satellite images (Landsat TM, ETM + , and OLI) and statistical-based methods (endpoint rate, linear regression rate and weighted linear regression). The long-term assessment during 1990–2015 shows that shoreline accredited at the rate of 0.3 m a−1 with estimated mean accretion and erosional rate of 1.18 m a−1 and 0.64 m a−1, respectively. A significant trend of coastal erosion is primarily observed on the northern side of Puri district coast. A cyclic pattern of accretion (during 1990–1995 and 2000–2004) and erosion (during 1995–2000 and 2009–2015) was observed during the assessment of short-term shoreline change. It exhibited significant correlation with the landfall of severe cyclones and identified cyclic phases after severe cyclonic storms, i.e., phase of erosion, phase of accretion and phase of stabilization. Overall, the natural processes specifically the landfall of tropical cyclones and anthropogenic activities such as the construction of coastal structures, encroachment and recent construction in the coastal regulatory zone, and construction of dams in upper catchment areas are the major factors accountable for shoreline changes. The output of the research undertaken is not only crucial for monitoring the dynamism of coastal ecosystem boundaries but to enable long- to short-term coastal zone management planning in response to recently reported high erosion along the Puri coast. Moreover, the usage of open-source satellite imageries and statistical-based method provides an opportunity in developing cost-effective spatial data infrastructure for shoreline monitoring and vulnerability mapping along the coastal region.

Masked shoreline erosion at large spatial scales as a collective effect of beach nourishment

Abstract: Sea‐level rise along the low‐lying coasts of the world's passive continental margins should, on average, drive net shoreline retreat over large spatial scales (>102 km). A variety of natural physical factors can influence trends of shoreline erosion and accretion, but trends in recent rates of shoreline change along the U.S. Atlantic Coast reflect an especially puzzling increase in accretion, not erosion. A plausible explanation for the apparent disconnect between environmental forcing and shoreline response along the U.S. Atlantic Coast is the application, since the 1960s, of beach nourishment as the predominant form of mitigation against chronic coastal erosion. Using U.S. Geological Survey shoreline records from 1830–2007 spanning more than 2500 km of the U.S. Atlantic Coast, we calculate a mean rate of shoreline change, prior to 1960, of ‐55 cm/yr (a negative rate denotes erosion). After 1960, the mean rate reverses to approximately +5 cm/yr, indicating widespread apparent accretion despite steady (and, in some places, accelerated) sea‐level rise over the same period. Cumulative sediment input from decades of beach nourishment projects may have sufficiently altered shoreline position to mask "true" rates of shoreline change. Our analysis suggests that long‐term rates of shoreline change typically used to assess coastal hazard may be systematically underestimated. We also suggest that the overall effect of beach nourishment along of the U.S. Atlantic Coast is extensive enough to constitute a quantitative signature of coastal geoengineering, and may serve as a bellwether for nourishment‐dominated shorelines elsewhere in the world.

Combination of Aerial, Satellite, and UAV Photogrammetry for Mapping the Diachronic Coastline Evolution: The Case of Lefkada Island

Abstract: Coastline evolution is a proxy of coastal erosion, defined as the wasting of land along the shoreline due to a combination of natural and/or human causes. For countries with a sea border, where a significant proportion of the population lives in coastal areas, shoreline retreat has become a very serious global problem. Remote sensing data and photogrammetry have been used in coastal erosion mapping for many decades. In the current study, multi-date analogue aerial photos, digital aerial photos, and declassified satellite imagery provided by the U.S. Geological Survey (USGS), Pleiades satellite data, and unmanned aerial vehicle images were combined for accurate mapping of the southwestern Lefkada (Ionian Sea, Greece) coastline over the last 73 years. Different photogrammetric techniques were used for the orthorectifation of the remote sensing data, and geographical information systems were used in order to calculate the rates of shoreline change. The results indicated that the southwest shoreline of Lefkada Island is under dynamic equilibrium. This equilibrium is strongly controlled by geological parameters, such as subsidence of the studied shoreline during co-seismic deformation and mass wasting. The maximum accretion rate was calculated at 0.55 m per year, while the respective erosion rate reached −1.53 m per year.

Photogrammetric assessment of shoreline retreat in North Africa: Anthropogenic and natural drivers

Abstract: Shoreline retreat along extended semi-arid areas of North African coasts are indicative of the imbalance of coastal sedimentary processes due to modern abrupt changes in precipitation patterns and urban growth. Monitoring of the diachronic shoreline position and land-use from 1952 to 2018 in the coast of the Hammamet Bay in central-east Tunisia, using both aerial and orbital photogrammetric scenes and the Digital Shoreline Analysis System from 1887 to 2018, suggests shoreline retreat rates ranging from −1.3 to −5.6 m/yr. Such rates are abnormal when compared to the average of −0.07 m/yr suggested by global-scale assessment modeling for sandy beach evolution. These abnormal erosions extend over 65 km of sandy beaches, resulting from a severe deficit of sediment transport caused primarily by rapid coastal urban growth that obstructs sediment flow to the shoreline. We suggest that the high retreat rates observed in the low-population period of 1884–1931 originated mainly from storm surges and tsunamis, or potentially subsidence in the coastal substratum. Moreover, our analysis of the salinity of shallow coastal aquifers and land coverage suggests that shoreline retreat coupled with rapid urban growth accelerated seawater intrusion ~5 km inland, causing soil desiccation, the development of salt lakes, and reduction of vegetation coverage by ~18%. These abrupt environmental changes have a severe, adverse impact on crop production and food security in these densely populated and economically important areas across significant parts of the North African coasts, sharing similar key environmental parameters with our study site. We conclude that anthropogenic drivers are the major source of shoreline retreat rather than natural ones.

Tsunami Simulations of the Sulawesi M w 7.5 Event: Comparison of Seismic Sources Issued from a Tsunami Warning Context Versus Post-Event Finite Source

Abstract: The 28 September 2018 Sulawesi earthquake generated a much larger tsunami than expected from its Mw = 7.5 magnitude and from its dominant strike-slip mechanism. Within a few minutes after the earthquake, the tsunami devastated the seafront of Palu bay, destroying houses and infrastructures over a few hundred meters. Coastal subsidence and slumping at various locations around the bay were also observed. There is debate in the scientific community as to whether submarine landslides and shore collapses contributed to the generation of strong and destructive waves locally. The objective of this study is threefold: first, to determine whether standard seismic inversions could predict the source in the context of tsunami early warning; second, to define a new seismic source built from optical image correlation and based on the geological and tectonic context; third, to assess whether the earthquake alone is able to generate up to 9-m wave heights at the coast. Numerical simulations of the tsunami propagation are performed for different seismic dislocation sources. Nonlinear shallow water equations are solved by a finite-difference method in grids with 200-m and 10-m resolutions. The early CMT focal solutions calculated by seismological institutes show dominant strike-slip mechanisms with a homogenous slip distribution. These sources produce maximum tsunami heights of 40-cm on the coast of Palu city. Two heterogeneous sources are tested and compared: the USGS “finite fault” model calculated from seismic inversion and a new “hybrid” source inferred from different techniques. The latter is based on a segmented fault in agreement with the geological context and built from both from seismic parameters of a CMT solution and the observed horizontal ground displacements. This source produces water wave heights of 4 to 5-m in the Palu bay. The observed inundation heights and distances are reproduced satisfactorily by the model at Pantoloan and at the southwestern tip of Palu bay. However, the “hybrid” source is unable to reproduce the largest 8 to 12-m water heights as reported from field surveys. Thus, even though this “hybrid” source produces most of the reported tsunami energy, we cannot exclude that the numerous coastal collapses observed in Palu bay contributed to increase the local tsunami run-up.

Transmission Design and Analysis for Large-Scale Offshore Wind Energy Development

Abstract: The offshore wind resource is very large in many coastal regions, over 80,000 MW capacity in the region studied here. However, the resource cannot be utilized unless distant offshore wind generation can be effectively collected and brought to shore. Based on extensive oceanographic, environmental, and shipping data, a realistic wind energy deployment layout is designed with 160 wind power plants each 500 MW. The power collection and transmission infrastructure required to bring this power to shore and connect it to the electricity grid is designed and analyzed. Three types of connection to shore are compared; high voltage AC to the nearest onshore point of interconnection (POI), high voltage DC with voltage-source converter (HVDC-VSC) to the nearest onshore POI, and connecting to an offshore HVDC backbone running parallel to shore that interconnects multiple wind power plants and multiple POIs ashore. The electrical transmission losses are estimated step by step from the wind turbines to the POI. The results show that such a large system can be built with existing technology in near-load resources, and that losses in the HVDC-VSC systems are approximately 1%–2% lower than that in the AC system for a distance about 120 km from shore.

Microbial communities across nearshore to offshore coastal transects are primarily shaped by distance and temperature.

Abstract: Recent studies have focused on linking marine microbial communities with environmental factors, yet, relatively little is known about the drivers of microbial community patterns across the complex gradients from the nearshore to open ocean Here, we examine microbial dynamics in 15 five-station transects beginning at the estuarine Piver's Island Coastal Observatory (PICO) time-series site and continuing 87 km across the continental shelf to the oligotrophic waters of the Sargasso Sea 16S rRNA gene libraries reveal strong clustering by sampling site with distinct nearshore, continental shelf and offshore oceanic communities Water temperature and distance from shore (which serves as a proxy for gradients in factors such as productivity, terrestrial input and nutrients) both most influence community composition However, at the phylotype level, modelling shows the distribution of some taxa is linked to temperature, others to distance from shore and some by both factors, highlighting that taxa with distinct environmental preferences underlie apparent clustering by station Thus, continental margins contain microbial communities that are distinct from those of either the nearshore or the offshore environments and contain mixtures of phylotypes with nearshore or offshore preferences rather than those unique to the shelf environment

Lagrangian observations of estuarine residence times, dispersion, and trapping in the Salish Sea

Abstract: Estuaries are important mediators in the transport of freshwater, sediment, and dissolved material into the ocean, and many studies have investigated mean estuarine circulation. However, it is not clear how descriptions of the mean circulation are linked to the motion of individual water parcels, or of discrete items floating within the system, nor how they related to the variability in this dispersal. An obvious approach to characterizing this variability is to actually measure dispersal by tracking Lagrangian drifters. Recent technological advances have dramatically decreased the cost of satellite-tracked and monitored drifters, making longer deployments of large numbers of expendable drifters much more feasible. Here we take advantage of this opportunity to directly characterize the seaward flow and dispersion of surface water in a relatively well-studied estuarine system (the Salish Sea on the NE Pacific coast), combining 2200 drifter-days of data from more than 400 tracked drifters with the deployment of nearly 6000 traditional driftcards. Residence times in different parts of the system estimated from the drifter observations are similar but systematically lower than those derived from other methods, and we speculate that this may be because surface drifts are faster than layer-mean drifts in a fjord-type estuarine system. We also find that drifters tend to ground on shore, and that time to-grounding from different source locations has an approximately exponential distribution with a mean of only a few days, much less than the transport time to the ocean. The estuary is therefore a highly efficient trap for floating objects. Finally, we quantify a dispersion coefficient, finding that dispersion is a critical component of transport in parts of the Salish Sea, often much more important than mean advection. The mean is visible only after averaging for weeks or months.

Shore Construction Detection by Automotive Radar for the Needs of Autonomous Surface Vehicle Navigation

Abstract: Autonomous surface vehicles (ASVs) are becoming more and more popular for performing hydrographic and navigational tasks. One of the key aspects of autonomous navigation is the need to avoid collisions with other objects, including shore structures. During a mission, an ASV should be able to automatically detect obstacles and perform suitable maneuvers. This situation also arises in near-coastal areas, where shore structures like berths or moored vessels can be encountered. On the other hand, detection of coastal structures may also be helpful for berthing operations. An ASV can be launched and moored automatically only if it can detect obstacles in its vicinity. One commonly used method for target detection by ASVs involves the use of laser rangefinders. The main disadvantage of this approach is that such systems perform poorly in conditions with bad visibility, such as in fog or heavy rain. Therefore, alternative methods need to be sought. An innovative approach to this task is presented in this paper, which describes the use of automotive three-dimensional radar on a floating platform. The goal of the study was to assess target detection possibilities based on a comparison with photogrammetric images obtained by an unmanned aerial vehicle (UAV). The scenarios considered focused on analyzing the possibility of detecting shore structures like berths, wooden jetties, and small houses, as well as natural objects like trees or other kinds of vegetation. The recording from the radar was integrated into a single complex radar image of shore targets. It was then compared with an orthophotomap prepared from AUV camera pictures, as well as with a map based on traditional land surveys. The possibility and accuracy of detection for various types of shore structure were statistically assessed. The results show good potential for the proposed approach—in general, objects can be detected using the radar—although there is a need for development of further signal processing algorithms.

Wave climate projections along the Indian coast

Abstract: Future changes in wave climate will influence the marine ecosystem, coastal erosion, design of coastal defences, operation of near- and off-shore structures, and coastal zone management policies and may further add to the potential vulnerabilities of coastal regions to projected sea level rise. Many studies have reported changes in the global wave characteristics under climate change scenarios, but it is important to project future changes in local/regional wave climate for smooth implementation of policies and preventing severe coastal erosion and flooding. In this study the regional wave climate along the Indian coast for two time slices, 2011–2040 and 2041–2070, is reported using an ensemble of near-surface winds generated by four different CMIP5 general circulation models (GCMs), under RCP4.5 scenario. Comparison of the wave climate for the two time slices shows an increase in wave heights and periods along much of the Indian coast, with the maximum wave heights increasing by more than 30% in some locations. An important finding is that at most locations along the east coast, wave periods are expected to increase by almost 20%, whereas along the west coast an increase of around 10% is expected. This will alter the distribution of wave energy at the shoreline through changes in wave refraction and diffraction, with potential implications for the performance and design of coastal structures and swash-aligned beaches. Furthermore, the computations show material changes in the directional distribution of waves. This is particularly important in determining the longshore transport of sediments and can lead to realignment of drift-aligned beaches, manifesting itself as erosion and/or siltation problems. This study is a preliminary contribution towards regional climate projections for the Indian Ocean region which are needed to plan and mitigate the impacts of future climate change.

Shelving the Coast With Vertipools: Retrofitting Artificial Rock Pools on Coastal Structures as Mitigation for Coastal Squeeze

Abstract: Coastal squeeze caused by sea level rise threatens the size, type and quality of intertidal habitats. Along coastlines protected by hard defences, there is a risk that natural rocky shore habitat will be lost, with remaining assemblages characteristic of hard substrata confined to sea walls and breakwaters. These assemblages are likely to be less diverse and different to those found on natural shores as these structures lack features that provide moist refugia required by many organisms at low tide, such as pools and crevices. Engineering solutions can help mitigate the impacts of sea level rise by creating habitats that retain water on existing structures. However, as experimental trials are strongly affected by local conditions and motivations, the development of new techniques and solutions are important to meet the needs of local communities and developers. Following a small scale community project, a feasibility study retrofitted five concrete-cast artificial rock pools (‘Vertipools’) on to a vertical seawall on the south coast of England. After 5 years, the artificial pools increased the species richness of the sea wall and attracted mobile fauna previously absent, including fish and crabs. The Vertipools had assemblages which supported several functional groups including predators and grazers. Although disturbance of algal assemblages on the seawall from the retrofitting process was still evident after 3 years, succession to full canopy cover was underway. Collaboration between policy makers, ecologists, children and artists produced an ecologically sensitive design that delivered substantial benefits for biodiversity and that could be adapted and scaled-up to both mitigate habitat loss and enhance coastal recreational amenity.