Coastal Exposure Research Articles

An integrated coastal exposure modelling approach to Foster mangrove-based disaster risk reduction (eco-DRR) in Tamil Nadu, India

This paper attempts to measure the role of the mangrove ecosystem in minimizing coastal exposure using the InVEST (V3.9.0) Coastal Vulnerability Assessment (CVA) model in Tamil Nadu, India. The result depicts that the exposure value of the Tamil Nadu coastal stretch varies from 1.71 to 4.78 on a five-point scale. More than half of the coastal segments in Tamil Nadu have high to very high exposure, whereas nearly 10 % of the coastal segments are recorded under very low exposure. The model demonstrated that having the existing mangrove patches in the Pichavaram and Muthpet regions significantly reduces the exposure value from 3.47 to 2.80 and 4.78 to 2.10, respectively. Further, the present study modelled the impact of future Sea Level Rise (SLR) on the mangrove ecosystems using a static inundation modelling approach under different Representative Concentration Pathways (RCPs). Results depict a significant loss of mangrove habitats from 9.55 % to 58.33 % and 20.88 % to 48.02 % for both the Pichavaram and Muthupet mangrove regions, respectively, by the end of this century (2100). Since the coastal hazards are expected to intensify, our results can benefit policymakers by highlighting the prioritized areas and location-specific interventions for fostering ecosystem-based disaster risk reduction (Eco-DRR) strategies.

Predicted ecological consequences of wave energy extraction and climate-related changes in wave exposure on rocky shore communities

Abstract Wave energy has the potential to contribute in the transition to decarbonized electricity generation. Extracting wave energy might be expected to have ecological impacts on rocky shore intertidal communities where exposure is one of the most important factors determining species structure and composition. With global climatic change, coastal exposure is predicted to increase with greater significant wave height. The wave-exposed west coast of Orkney, Scotland, UK, is the site of pre-commercial wave device testing. Surveys of 39 rocky shore sites along this coast identified key species and abundances, and quantified exposure-modifying topographic variables. A spectral wave model was constructed to compare baseline, wave extraction, climate change, and combined scenarios. Generalized additive modelling was used to describe the relationship between species, topography, and exposure. Results show that individual species differentially respond to exposure changes with ‘winners’ and ‘losers’ at site level. Overall, community responses are expected to be far greater following predicted climatic change than to industrial-scale wave energy extraction, depending on spatial scale. In combination, energy extraction may reduce the effects of climate-change-related increases in wave exposure of rocky shores. Predicting how location-specific biotic assemblages respond to changes in wave energy as a result of long-term forcing agents provides a valuable marine resource management tool.

The influence of crystalline technology as concrete admixture on compressive strength and permeability

In regions prone to frequent rainfall or coastal exposure, concrete gradually becomes porous due to environmental influences. This study systematically examines the impact of different concrete formulations on compressive strength and permeability. It evaluates standard concrete, concrete with 1% and 2% crystalline admixtures, and concrete utilizing Portland cement type V. Compressive strength tests reveal that concrete with 1% and 2% crystalline admixtures, alongside Portland cement type V concrete, exhibit superior quality compared to standard concrete. Permeability assessments unveil intriguing trends: Portland cement type V concrete displays heightened permeability relative to standard concrete, while 1% and 2% crystalline admixture concretes exhibit significantly reduced permeability, surpassing both standard concrete and Portland cement type V concrete. The heightened concrete density associated with crystalline admixtures can be attributed to their dual influence on augmenting compressive strength and decreasing permeability. By reinforcing these mechanisms, crystalline admixtures effectively enhance concrete durability. This research contributes to the understanding of advanced construction materials and offers insights into sustainable infrastructure development possibilities. Subsequent sections delve into experimental intricacies, result explications, and wider implications of these findings, shaping the trajectory of future construction practices.

Increasing coastal exposure to extreme wave events in the Alaskan Arctic as the open water season expands

Declining Arctic sea ice over recent decades has been linked to growth in coastal hazards affecting the Alaskan Arctic. In this study, climate model projections of sea ice are utilized in the simulation of an extratropical cyclone to quantify how future changes in seasonal ice coverage could affect coastal waves caused by this extreme event. All future scenarios and decades show an increase in coastal wave heights, demonstrating how an extended season of open water in the Chukchi and Beaufort Seas could expose Alaskan Arctic shorelines to wave hazards resulting from such a storm event for an additional winter month by 2050 and up to three additional months by 2070 depending on climate pathway. Additionally, for the Beaufort coastal region, future scenarios agree that a coastal wave saturation limit is reached during the sea ice minimum, where historically sea ice would provide a degree of protection throughout the year.

Urban resilience against environmental disasters: Comparing Lagos and New York

Urban resilience against environmental disasters is a critical aspect of sustainable urban development, particularly in megacities like Lagos and New York, which face diverse environmental challenges. This review examines the comparative analysis of urban resilience strategies in Lagos, Nigeria, and New York City, USA, focusing on their responses to environmental disasters. Both cities encounter distinct environmental hazards, including flooding, hurricanes, and heatwaves, albeit within different socio-economic contexts. Lagos, Africa's most populous city, grapples with rapid urbanization, inadequate infrastructure, and informal settlements, exacerbating its vulnerability to environmental disasters. In contrast, New York City, a global financial hub, confronts challenges posed by its dense urban fabric, aging infrastructure, and coastal exposure. Despite differing contextual factors, both cities strive to enhance their resilience through various strategies. Lagos employs a mix of top-down and bottom-up approaches, emphasizing community engagement, early warning systems, and infrastructure improvements to mitigate flood risks. Initiatives such as the Lagos State Resilience Strategy and the implementation of green infrastructure projects signify efforts to enhance adaptive capacity and reduce vulnerability. Conversely, New York City adopts a multifaceted approach, integrating policy frameworks, technological innovations, and community-based initiatives to bolster resilience. Post-Hurricane Sandy, the city launched the "OneNYC" plan, emphasizing infrastructure upgrades, coastal protection measures, and climate adaptation strategies to withstand future shocks. Comparative analysis reveals both convergences and divergences in urban resilience strategies. While Lagos prioritizes grassroots involvement and low-cost solutions, New York emphasizes institutional coordination and investment in resilient infrastructure. Challenges persist in both contexts, including funding constraints, governance issues, and socio-economic disparities, underscoring the need for holistic and inclusive resilience frameworks. Understanding the nuances of urban resilience in diverse contexts can inform policy interventions and best practices transferable across cities globally. By examining the experiences of Lagos and New York, this review contributes to the discourse on building resilient cities capable of navigating environmental uncertainties and safeguarding the well-being of urban populations.

Using vulnerability assessment to characterize coastal protection benefits provided by estuarine habitats of a dynamic intracoastal waterway.

The existence of coastal ecosystems depends on their ability to gain sediment and keep pace with sea level rise. Similar to other coastal areas, Northeast Florida (United States) is experiencing rapid population growth, climate change, and shifting wetland communities. Rising seas and more severe storms, coupled with the intensification of human activities, can modify the biophysical environment, thereby increasing coastal exposure to storm-induced erosion and inundation. Using the Guana Tolomato Matanzas National Estuarine Research Reserve as a case study, we analyzed the distribution of coastal protection services-expressly, wave attenuation and sediment control-provided by estuarine habitats inside a dynamic Intracoastal waterway. We explored six coastal variables that contribute to coastal flooding and erosion-(a) relief, (b) geomorphology, (c) estuarine habitats, (d) wind exposure, (e) boat wake energy, and (f) storm surge potential-to assess physical exposure to coastal hazards. The highest levels of coastal exposure were found in the north and south sections of the Reserve (9% and 14%, respectively) compared to only 4% in the central, with exposure in the south driven by low wetland elevation, high surge potential, and shorelines composed of less stable sandy and muddy substrate. The most vulnerable areas of the central Reserve and main channel of the Intracoastal waterway were exposed to boat wakes from larger vessels frequently traveling at medium speeds (10-20 knots) and had shoreline segments oriented towards the prevailing winds (north-northeast). To guide management for the recently expanded Reserve into vulnerable areas near the City of Saint Augustine, we evaluated six sites of concern where the current distribution of estuarine habitats (mangroves, salt marshes, and oyster beds) likely play the greatest role in natural protection. Spatially explicit outputs also identified potential elevation maintenance strategies such as living shorelines, landform modification, and mangrove establishment for providing coastal risk-reduction and other ecosystem-service co-benefits. Salt marshes and mangroves in two sites of the central section (N-312 and S-312) were found to protect more than a one-quarter of their cross-shore length (27% and 73%, respectively) from transitioning to the highest exposure category. Proposed interventions for mangrove establishment and living shorelines could help maintain elevation in these sites of concern. This work sets the stage for additional research, education, and outreach about where mangroves, salt marshes, and oyster beds are most likely to reduce risk to wetland communities in the region.

The Dunes Contribution to the Ecosystem Service of Coastal Protection on the Northern Coast of RS

Coastal dunes have a crucial role in offering the ecosystem service of natural coastal protection. This paper investigates the importance of dunes in providing the ecosystem service of natural coastal protection on the North Coast of the State of Rio Grande do Sul (RS) in southern Brazil. The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST®) Coastal Vulnerability Model was used to quantify the relative susceptibility to coastal erosion and flooding within the study area. First, the model was run to assess the susceptibility to coastal hazards considering the presence of dunes. Then, the model was run again without the presence of dunes. By comparing the results of the two model simulations, it was possible to identify where dunes contribute to reducing coastal exposure, which indirectly reflects their role in providing the ecosystem service of natural coastal protection. There are two main dune fields in the study area, one in the northern coastal sector and one in the southern sector, respectively in the municipalities of Torres and Cidreira. The index of exposure values produced by the two model simulations were very similar for locations along the Torres coastline. In contrast, along the coast of Cidreira, results from the model simulation without dunes produced higher exposure values than the simulation with the presence of dunes, suggesting that the dunes have an important role in offering natural coastal protection. Dunes are a natural barrier against coastal erosion and flooding, but they are not the only factor influencing the ecosystem service of coastal protection. In Torres, for instance, the local topography and the wind patterns contribute to reducing local exposure. The greatest threat in this sector is the urban sprawl.

Perception of climate change impacts, urbanization, and coastal planning in the Gaeta Gulf (central Tyrrhenian Sea): A multidimensional approach

<abstract> <p>The coasts, with their intricate combination of natural and anthropogenic fragilities, can always be considered a crucial component in the geography of risk and territorial governance. Furthermore, coastal areas worldwide are currently facing profound and immediate impacts of climate change, presenting unparalleled challenges for both ecosystems and coastal communities. In these contexts, high socio-environmental vulnerability has often been linked to planning and management practices that, at times, have exacerbated coastal exposure, making it more prone to extreme natural phenomena, such as coastal floods and storm surges, as well as degradation. The case of the Gaeta Gulf, a largely urbanized part of the central Tyrrhenian coast in Italy that encompasses two administrative areas between the northern Campania and the southern Lazio Regions, provides an opportunity to investigate these criticalities both along the coastline and within the interconnected inland areas. This research aims to understand how administrations and communities perceive, experience, and understand the coastal risks and challenges posed by climate change, as well as their level of information and preparedness to address such risks. These aspects will be analyzed through a multidisciplinary approach, shedding light on the political, social, environmental, and economic practices in these areas, and the potential implications for coastal planning policies. In addition, this contribution presents the results of a qualitative survey involving the administration of questionnaires related to the perception of climate change impacts on the coasts and the level of information on the mitigation and adaptation practices within the communities living in these areas.</p> </abstract>

Nikolaevo-Otradnoye II—A New Early and Middle Paleolithic Site in the Northeastern Azov Region

We describe materials from a new Paleolithic site, discovered in 2020 on the right bank of Mius estuary, near its confl uence with the Taganrog Bay of the Sea of Azov, in the southern outskirts of the village of Nikolaevo-Otradnoye, which is in the Neklinovksky District of the Rostov Region. The clearing of a 10-meter-high river-bluff revealed a complex stratigraphy of subaqueous and subaerial Late and Middle Pleistocene rocks. Horizons with lithics and faunal remains were identifi ed. Cultural remains found in the coastal exposure and in the stratigraphic section belong to the Early and Middle Paleolithic. The early stage in the peopling of the Northeastern Azov and the Lower Don regions is documented by Early Paleolithic artifacts found in the subaqueous deposits of layers 5 and 6 (MIS 9–11, ~420– 270 ka BP). Heavil y waterworn patinated lithics include a core-shaped artifact, variou s types of side-scrapers, a scaled piece, fl akes, and chips. This complex is an informative addition to known complexes from the region, including contemporaneous ones. The most interesting is the Middle Paleolithic industry of layer 4 under the Kamenka (?) soil— layer 3, MIS 7. The toolkit consists of a diagonal side-scraper and a chip found in the section, as well as radial and Levallois cores, various side-scrapers, a par tly bifacial tool, spalls , and chips found in the denudation. Technological and typological criteria (primarily the Levallois technology) and the tentative date of non-waterworn patinated lithics make it possible to attribute them to the Early Middle Paleolithic of the southern Russian Plain. It is concluded that cultural remains of the Early Middle Paleolithic, dating to ~243–191 ka BP, have been found in the region for the fi rst time, fi lling the gap in the local Early Middle Paleolithic sequence. In adjacent regions, similar industries have been known since the late 1900s.

Vulnerability of sea turtle nesting sites to erosion and inundation: A decision support framework to maximize conservation

AbstractSandy beaches provide essential nesting habitats for sea turtles but are threatened globally by a rapidly changing climate. Identifying which nesting sites are at the greatest risk from erosion and inundation remains an important goal of sea turtle conservation globally. Yet, efforts to identify at‐risk sites have been hindered by the ability to model complex processes and incomplete information on nesting distribution and abundance. To assess the erosion and inundation risk to the reproductive success of a discrete genetic stock of flatback turtles (Natator depressus) across its nesting range in the Pilbara region of Western Australia, we used the Integrated Valuation of Ecosystem Services and Trade‐offs (InVEST) Coastal Vulnerability Model. A relative exposure index was calculated for 402 nesting beaches in terms of six geophysical variables: wind and wave exposure, surge potential, relief, observed sea level rise, and coastal geomorphology, and coupled with published information on the distribution and abundance of turtle tracks in the region. The majority of beaches (74%) had intermediate to high exposure. In particular, 36% of beaches with a high abundance of flatback tracks (the top 25% of the frequency distribution) had a high exposure (the top 25% of the frequency distribution). This suggests that coastal exposure is a key vulnerability to the reproductive success of sea turtles that nest in this region. Promisingly, five beaches with a high abundance of turtle tracks also had a low exposure (bottom 25% of the frequency distribution), and these beaches may be critical for the long‐term resilience of the stock against sea level rise and severe storms. Exposure varied across nesting sites, and the approach presented here allows for a rapid and broadscale assessment of relative erosion and inundation risks at a scale most relevant to management.

New LiDAR‐Based Elevation Model Shows Greatest Increase in Global Coastal Exposure to Flooding to Be Caused by Early‐Stage Sea‐Level Rise

AbstractThe latest projections indicate that sea‐level rise (SLR) is certain to exceed 2 m in coming centuries, and a rise by 4 m is considered possible. Radar‐based land elevation models applied to date suggest that the increase of area below mean sea level, that is potentially exposed to permanent flooding, will accelerate as SLR proceeds, being relatively limited initially. However, applying new and more accurate satellite LiDAR elevation data we find the opposite pattern, with the fastest increase in the area of exposed land occurring in the early stages of SLR. In one‐third of countries most of this increase will be caused by the first meter of SLR and in nearly all within the first 2 m. We conclude that in many regions the time available to prepare for increased exposure to flooding may be considerably less than assumed to date, and that better elevation data will support timely preparations. The global LiDAR lowland DTM (GLL_DTM_v2) elevation data set developed for this assessment is available in the public domain.

Understanding the Drivers of Coastal Flood Exposure and Risk From 1860 to 2100

AbstractGlobal coastal flood exposure (population and assets) has been growing since the beginning of the industrial age and is likely to continue to grow through 21st century. Three main drivers are responsible: (a) climate‐related mean sea‐level change, (b) vertical land movement contributing to relative sea‐level rise, and (c) socio‐economic development. This paper attributes growing coastal exposure and flood risk from 1860 to 2100 to these three drivers. For historic flood exposure (1860–2005) we find that the roughly six‐fold increase in population exposure and 53‐fold increase in asset exposure are almost completely explained by socio‐economic development (>97% for population and >99% for assets). For future exposure (2005–2100), assuming a middle‐of‐the‐road regionalized socio‐economic scenario (SSP2) without coastal migration and sea‐level rise according to RCP2.6 and RCP6.0, climate‐change induced sea‐level rise will become the most important driver for the growth in population exposure, while growth in asset exposure will still be mainly determined by socio‐economic development.

Transfer Parameter Analysis of Chloride Ingress into Concrete Based on Long-Term Exposure Tests in China’s Coastal Region

Chloride penetration resistance is one of the most important performance measures for the evaluation of the durability of concrete under a chloride environment. Due to differences in theory and experimental conditions, the durability index (chloride diffusion coefficient) obtained from laboratory accelerated migration tests cannot reflect the real process of chloride ingress into concrete in the natural environment. The difference in test methods must be considered and the transfer parameter kt should be introduced into the service life prediction model when the test results of accelerated methods are used. According to the test data of coastal exposure in South China, the attenuation rule of the chloride diffusion coefficient of different cement-based materials changed with time and was analyzed in this paper. Based on the diffusion coefficient-time curve, the theoretical natural diffusion coefficients of 28 d and 56 d were deduced, which were compared with the chloride diffusion coefficients obtained from the non-steady-state rapid migration method (RCM) at the same age. Therefore, the transfer parameter kt that expounds the relationship between concrete resistance to chloride permeability under a non-stationary electrical accelerated state and natural diffusion in the marine environment can be calculated; thus, the RCM testing index can be used to evaluate the long-term performance of the concrete structure in the marine environment. The results show that the value of kt was related to environmental conditions, test methods, and binder systems.

Microvertebrate-rich gutter casts from the basal Wessex Formation (Wealden Group, Lower Cretaceous) of Dungy Head, Dorset: Insights into the palaeoecology and palaeoenvironment of a non-marine wetland

A detailed taxonomic, taphonomic and sedimentological examination of a newly discovered microvertebrate-rich horizon within the non-marine, Lower Cretaceous Wessex Formation (Wealden Group) of Dungy Head, Dorset, aids the ecological and palaeoenvironmental reconstruction of southern England's Early Cretaceous wetlands. Historically, the Wessex Formation of Dungy Head has been neglected due to its partially vegetated state and landslipped coastal exposure; here the section's palaeontological and stratigraphical significance is realised. Non-marine, cypridoidean ostracods indicate a depositional age of late Berriasian–early Valanginian; consequently, the faunal assemblage recorded here represents the oldest fauna to be described from the Wessex Formation to date. Significantly, winnow-induced gutter casts are shown to be an important repository of mixed aquatic and terrestrial microvertebrate remains. Hydraulic sorting within a fluvial environment has resulted in the formation of multi-taxic, microvertebrate-rich gutter casts that through close lateral and stratigraphical association form a unique, bone-rich taphofacies. The recorded assemblage is typical of wetland biodiversity containing a minimum of 25 taxa including, non-marine molluscs, ostracods, elasmobranchs, osteichthyans, and tetrapods. Importantly, the gutter casts permit the taxonomic evaluation of a primarily aquatic biota in which albuliform fishes are recorded from the Wessex Formation for the first time. The biota also includes a diverse elasmobranch fauna, including hybodontoid sharks and a rhinobatid ray. Furthermore, lepidosaurs, including both scincomorphs and, tentatively, an anguimorph, are confirmed in the Wessex Formation of Dorset.

The protective role of mangroves in safeguarding coastal populations through hazard risk reduction: A case study in northeast Brazil

Coastal and estuarine ecosystems such as mangroves provide coastal protection services, safeguarding coastal communities and economies. However, sea-level rise can affect mangroves' protective role by increasing exposure to coastal hazards and economic costs. To better understand the role of mangroves as coastal protective barriers against hazards and their importance for conservation planning in the face of sea-level rise, we first analyzed temporal changes in the coastal landscape by measuring the erosion/accretion rates on the shoreline. We assessed coastal exposure to hazards with the presence and absence of mangroves. Finally, we estimated the economic losses and costs from the long-term retreat in the shoreline and mangrove loss. This study was carried out along the western coast of the South Atlantic, in the northeast Brazilian region. Coastal exposure indices were estimated using the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) software, and the multitemporal analysis of shoreline was developed using the Digital Shoreline Analysis System (DSAS) software. Finally, the economic losses produced by those shoreline changes and social costs were estimated by predicting economic losses in terms of private property and by calculating societal costs in mangrove restoration and rockfill building. The results show that nearly a third of the shoreline is experiencing erosion and the coast could lose an additional 118 ha by 2030. In terms of the value of property loss, this translates to US$38,800 and would increase to US$72,000 under the maximum erosion rate scenario. Based on our coastal vulnerability assessment, almost 50 km of the coastline (20%) would transition to intermediate-high exposure levels if the current distribution of mangroves were to be lost. It is expected to cost about US$145 million in rockfill works and US$21 million in forest restoration to mitigate the impacts from human activities and sea-level rise on mangroves ecosystem services. At the national level, a total loss of mangroves in Brazil could mean mangrove forest restoration costs of nearly US$4000 million. More robust conservation policies are needed to conserve mangrove forests and safeguard the ecosystem-service co-benefits they provide. The latter is essential in low- and middle-income nations where the economic and welfare losses from coastal hazards are more challenging due to dependence on nature for livelihoods and well-being.

Mammoth Fauna Remains From Late Pleistocene Deposits of the Dmitry Laptev Strait South Coast (Northern Yakutia, Russia)

The Yedoma Ice Complex in northern Yakutia provides perfect preservation conditions for frozen remains of vertebrate animals. Even complete mummified specimens of the late Pleistocene Beringian Mammoth fauna such as woolly mammoth, woolly rhinoceros, horse, and bison are occasionally found in permafrost deposits across eastern Siberia, i.e., in West Beringia, although bones are much more commonly found. The present study characterizes mammal bones from late Pleistocene and Holocene permafrost deposits exposed on the Oyogos Yar coast, part of the southern shore of the Dmitry Laptev Strait that connects the Laptev and East Siberian seas. The study applies a method to characterize fossil bone samples by the location of their discovery and by the accuracy of their relation to a depositional horizon. We analyzed a total of 38 finite radiocarbon ages of bone material from mammoth, horse, and musk ox, spanning from about 48.8 to 4.5 ka BP and including both our own data and data from the literature, in addition to previous publications that reported numerous bones with infinite ages from the Oyogos Yar coast. The distribution of bones and tooth along the coastal permafrost exposure is not uniform; it depends upon whether the material was found in situ, on thermo-terraces, or on the shore. The overall bone collection consists of 13 species of which Mammuthus primigenius (woolly mammoth, 41%), Bison priscus (bison, 19%), Equus ex gr., caballus (horse, 19%), and Rangifer tarandus (reindeer, 16%) predominate. The fossil bone species distribution is similar to those of other prominent Yedoma outcrops in the region, i.e., on Bykovsky Peninsula and on Bol’shoy Lyakhovsky Island. Correlation analysis shows that the Oyogos Yar bone sampling sites of different geomorphological settings are similar to each other but not to all sampling sites within the other two locations on Bykovsky Peninsula and on Bol’shoy Lykahovsky Island. High similarities in terms of correlation coefficients between specific sampling sites are often not represented in the cluster analysis.

Vulnerability Analysis of Coastal Zone Based on InVEST Model in Jiaozhou Bay, China

The coastal zone plays an essential part in maintaining the balance of the ecosystem and promoting the development of human society and economy. It is significant to assess the extent to which the Jiaozhou Bay coastal zone withstands floods and coastal erosion during storms. The coastal exposure index (CEI) of the Jiaozhou Bay in 1984, 2000 and 2019 was obtained by the coastal vulnerability model based on data including coastline, bathymetry and coastal terrain elevation. The spatial distribution and aggregation characteristics of CEI in Jiaozhou Bay were analyzed through spatial autocorrelation analysis. The results show that the north coast of Jiaozhou Bay is highly vulnerable, that is, prone to coastal erosion, while the south and east are less vulnerable, meaning that they can basically withstand natural disasters such as storm surges and floods. The CEI shows significant spatial autocorrelation, with little spatial heterogeneity. The type of coastline, elevation, distance to continental shelf and socio-economic development are the main factors that cause the north–south vulnerability differences in the Jiaozhou Bay coast. The results can identify the districts along the Jiaozhou Bay that are at greater risk of marine disasters, and provide scientific theoretical support for the coastal protection and sustainable development of the Jiaozhou Bay.

Physiographic Controls on Landfast Ice Variability from 20 Years of Maximum Extents across the Northwest Canadian Arctic

Landfast ice is a defining feature among Arctic coasts, providing a critical transport route for communities and exerting control over the exposure of Arctic coasts to marine erosion processes. Despite its significance, there remains a paucity of data on the spatial variability of landfast ice and limited understanding of the environmental processes’ controls since the beginning of the 21st century. We present a new high spatiotemporal record (2000–2019) across the Northwest Canadian Arctic, using MODIS Terra satellite imagery to determine maximum landfast ice extent (MLIE) at the start of each melt season. Average MLIE across the Northwest Canadian Arctic declined by 73% in a direct comparison between the first and last year of the study period, but this was highly variable across regional to community scales, ranging from 14% around North Banks Island to 81% in the Amundsen Gulf. The variability was largely a reflection of 5–8-year cycles between landfast ice rich and poor periods with no discernible trend in MLIE. Interannual variability over the 20-year record of MLIE extent was more constrained across open, relatively uniform, and shallower sloping coastlines such as West Banks Island, in contrast with a more varied pattern across the numerous bays, headlands, and straits enclosed within the deep Amundsen Gulf. Static physiographic controls (namely, topography and bathymetry) were found to influence MLIE change across regional sites, but no association was found with dynamic environmental controls (storm duration, mean air temperature, and freezing and thawing degree day occurrence). For example, despite an exponential increase in storm duration from 2014 to 2019 (from 30 h to 140 h or a 350% increase) across the Mackenzie Delta, MLIE extents remained relatively consistent. Mean air temperatures and freezing and thawing degree day occurrences (over 1, 3, and 12-month periods) also reflected progressive northwards warming influences over the last two decades, but none showed a statistically significant relationship with MLIE interannual variability. These results indicate inferences of landfast ice variations commonly taken from wider sea ice trends may misrepresent more complex and variable sensitivity to process controls. The influences of different physiographic coastal settings need to be considered at process level scales to adequately account for community impacts and decision making or coastal erosion exposure.

Change and variability in Antarctic coastal exposure, 1979\u20132020

Increased exposure of Antarctica’s coastal environment to open ocean and waves due to loss of a protective sea-ice “buffer” has important ramifications for ice-shelf stability, coastal erosion, important ice-ocean-atmosphere interactions and shallow benthic ecosystems. Here, we introduce a climate and environmental metric based on the ongoing long-term satellite sea-ice concentration record, namely Coastal Exposure Length. This is a daily measure of change and variability in the length and incidence of Antarctic coastline lacking any protective sea-ice buffer offshore. For 1979–2020, ~50% of Antarctica’s ~17,850-km coastline had no sea ice offshore each summer, with minimal exposure in winter. Regional summer/maximum contributions vary from 45% (Amundsen-Bellingshausen seas) to 58% (Indian Ocean and Ross Sea), with circumpolar annual exposure ranging from 38% (2019) to 63% (1993). The annual maximum length of Antarctic coastal exposure decreased by ~30 km (~0.32%) per year for 1979–2020, composed of distinct regional and seasonal contributions.

‘Best day since the bad germs came’: Exploring changing experiences in and the value of coastal blue space during the COVID-19 pandemic, a Fylde Coast case study

Blue spaces have long been associated with beneficially impacting human health and wellbeing. This article reflects upon the impact of the COVID-19 pandemic on people’s experiences in coastal blue space and the health and wellbeing benefits derived from exposure to the space. Undertaken after the UK’s first lockdown during Summer 2020, the work employed a qualitative mixed methods approach through a survey and interviews to provide an in-depth case study of people’s experiences in and value of coastal blue space before and during the pandemic on the Fylde Coast in Lancashire. Findings show that participants valued the physical and mental health benefits derived from routine visits to coastal space, stimulated by emotional connections, a sense of escape and sensorial immersion. However, a busier coast in the lockdown’s aftermath provoked a changed experience in coastal space for many participants due to a detachment from coastal space and the provoking of negative emotional experiences driven by heightened fears, reduced safety and increased litter. Mitigatory responses, through a changed coastal routine, and reflective responses, through a changed value of the coast, were found, the latter due to an increased appreciation of the health benefits from coastal exposure for some participants. Importantly, the findings highlight the need for coastal management to account for these experiences in protecting the health value of coastal space.