Improving Coastal Vulnerability Assessment Methodologies for Integrated Coastal Zone Management: an Approach from South Australia

The global concern about human-induced climatic change and its potential effect on sea-level has dominated the debate on coastal vulnerability, particularly since a common assessment methodology was developed by the Intergovernmental Panel on Climate Change in 1991. There have been numerous attempts to use or adapt this methodology but the focus has remained on sea-level rise as the single most important issue for coastal vulnerability. This paper presents a revised and more holistic coastal vulnerability assessment methodology which incorporates spatial and temporal scales relevant to the predicted impacts of climatic change and current human-induced hazards. Three studies in contrasting coastal environments of South Australia demonstrate that there are significant regional variations in sea-level response, human-induced hazards and local planning issues and that these may present a greater immediate threat than the possibility of sea-level rise.     

Keeping Pace With Rising Sea: The First 6 Years of the Lower Suwannee Archaeological Survey,Gulf Coastal Florida

Low-gradient coastlines are susceptible to inundation by rising water, but they also promote marsh aggradation that has the potential to keep pace with sea-level rise. Synergies among hydrodynamics, coastal geomorphology, and marsh ecology preclude a simple linear relationship between higher water and shoreline transgression. As an archive of human use of low-gradient coastlines, archaeological data introduce additional mitigating factors, such as landscape alteration, resource extraction, and the cultural value of place. The Lower Suwannee Archaeological Survey (LSAS) is an ongoing effort to document the history of coastal dwelling since the mid-Holocene, when the rate and magnitude of sea-level rise diminished and the northern Gulf coast of Florida transitioned into an aggradational regime. Results of the first 6 years of the LSAS suggest that multicentury periods of relative stability were punctuated by site abandonment and relocation. Subsistence economies involving the exploitation of oyster and fish, however, were largely unaffected as communities redistributed themselves with changes in shoreline position and estuarine ecology. After AD 200, civic-ceremonial centers were established at several locations along the northern Gulf coast, fixing in place not only the infrastructure of daily living (villages), but also that of religious practice, notably cemeteries and ceremonial mounds. Intensified use of coastal resources at this time can be traced to a ritual economy involving large gatherings of people, terraforming, feasting, and the circulation of socially valued goods. To the extent that religious practices buffered the risks of coastal living, large civic-ceremonial centers, like aggrading marshes, afforded opportunities to “outpace” sea-level rise. On the other hand, centers introduced a permanence to coastal land-use that proved unsustainable in the long term.     

A Filtered Past: Interpreting Salt Production and Trade Models from Two Remnant Brine-Enrichment Mounds at the Ancient Maya Paynes Creek Salt Works,Belize

The mounds at Witz Naab and Killer Bee are the only known remaining aboveground evidence of a once-thriving salt industry in Punta Ycacos Lagoon, a large saltwater system in Paynes Creek National Park, Belize. Over one hundred ancient Maya salt works dated to the Classic period (a.d. 300–900) have been submerged by sea-level rise in the lagoon. We have hypothesized that mounds were once numerous features on the landscape prior to a sea-level rise that occurred in the area during the Terminal Classic period. Lacking at these underwater sites are earthen mounds formed by discarded soil from the leaching process in which the salinity of seawater was enriched by leaching brine through salty soil. Enriching the salinity of seawater by leaching or by solar evaporation is virtually universal in ethnographic case studies. Data from the excavations are evaluated to interpret the ancient activities that produced the earthen mounds, scales of production, and how the coastal Maya of southern Belize participated in the larger Classic Maya economy.     

PERCEPTIONS OF AND RESPONSES TO THE HOLOCENE FLOODING OF THE NORTH SEA LOWLANDS

This paper explores how the drastic landscape changes that took place in the North Sea basin during the Holocene affected the lives of those dwelling in that area. Previous contributions to the discussion of the Holocene inundation of the North Sea have tended to concentrate on the timings. This paper discusses the ways people could have perceived and responded to these events, emphasizing that climate change should not be viewed apart from social factors. It is also argued that sea-level rise was not something externally imposed on communities but an integral part of their world.     

New models of North West European Holocene palaeogeography and inundation

This paper presents new 500 year interval palaeogeographic models for Britain, Ireland and the North West French coast from 11000 cal. BP to present. These models are used to calculate the varying rates of inundation for different geographical zones over the study period. This allows for consideration of the differential impact that Holocene sea-level rise had across space and time, and on past societies. In turn, consideration of the limitations of the models helps to foreground profitable areas for future research.     

Coastal Feasts: A Pleistocene Antiquity for Resource Abundance in the Maritime Deserts of North West Australia?

ABSTRACT

Located on the edge of Australia's North West continental shelf, Barrow Island is uniquely located to address a number of research questions, such as the antiquity and changing nature of Indigenous occupation, including shifting uses of regional economic resources in response to post-glacial sea-level rise. These questions are addressed from a range of archaeological, zooarchaeological, and geoarchaeological disciplines. Although only preliminary, results to date indicate the presence of marine resources dating to before sea-level stabilization (～ 7.5 ka) that contain both dietary and utilitarian species, including high-ranked species such as sea turtle. The marine assemblages reflect a variety of habitats and substrates with a 17,000-year record for the presence of a former tidal marsh or estuary. We also note recently obtained ¹⁴C and OSL dates that extend the dietary marine faunas and initial occupation to well before 41 ka. This demonstrates that consumption of coastal resources began prior to the Holocene, when we begin to observe more widespread evidence of marine resource exploitation in the broader Canarvon Bioregion of northwest Australia. This evidence supports arguments for further research to directly test both the productivity of, and human reliance on, marine habitats from initial occupation.     

Holocene Relative Sea-Level Change on the Isle of Skye,Inner Hebrides,Scotland

Holocene relative sea-level (RSL) changes are described for the Isle of Skye, based upon evidence from isolation basins and back barrier environments. RSL rose across low-lying coastal areas in the early Holocene, inundating isolation basins in the Sleat peninsula, and then fell back in the early-middle Holocene before a fluctuating rise occurred later in the middle and late Holocene. A short-lived marine inundation at one site may have been caused by an episode of rapid RSL rise after the discharge of Lakes Agassiz–Ojibway in North America and/or the Holocene Storegga Slide tsunami, generated by submarine landsliding off South-West Norway. The empirical evidence for RSL change on Skye is compared with a recent shoreline-based glacio-isostatic adjustment model, which includes Skye, showing altitudes for the Holocene Storegga Slide tsunami, Main Postglacial, Blairdrummond and Wigtown shorelines in the area. The empirical evidence is shown to be in accord with the altitudes predicted by the model.     

Review on Late Pleistocene-Holocene relative sea-level changes in Kuwait: New evidence from Failaka island

New results from fieldwork carried out on Failaka island testify to relative sea-level fluctuations during Late Pleistocene and Holocene. This study is based on analysing, sampling and dating geomorphological sea-level indicators, including beach ridges or beachrocks. The results have been compared and harmonised with recalibrated data from pre-existing literature to reconstruct the relative sea-level local chronology. The vertical displacement identified may have induced coastline mobility and significant environmental changes and impacted the human occupation in Failaka and along the coastal areas of Kuwait. Eventually, the results highlight the impact of large-scale crustal deformations on regional relative sea-level variations.     

Hunter-gatherer land use in Late Glacial south-east Italy

This paper is concerned with the Late Palaeolithic settlement of south-eastern Italy at the close of the Pleistocene. The Late Palaeolithic assemblages of the region have been studied previously from a rigid typological stance, with various schemes put forward suggesting evolution of the assemblages through different stages of an Epigravettian tradition, while the potential role of social and economic factors in shaping the various industries has been ignored. This paper shows how the Late Palaeolithic occupation of the region should be considered in relation to the former existence of an extensive coastal plain and to the sea-level rise which submerged it. Factors such as the availability of lithic raw material and the alternative strategies by which it was procured, the particular activities in which the tools were used and the role of the sites within a larger land use system were clearly crucial to assemblage composition.     

Gorad Beuno: investigation of an ancient fish-trap in Caernarfon Bay, N. Wales

Aerial reconnaissance in 1989 revealed a semicircular structure lying just off the coast at Clynnog Fawr in Caernarfon Bay, North Wales. The similarity in shape of the structure to other coastal fish-traps in the area promoted further study. Several avenues of research were followed. Historical sources were scrutinized in an attempt to find a date for the construction of the structure. A hydrographic survey was used to obtain the exact position and shape of the anomaly. A survey of the cliff and beach directly inland of the site was also made.
The anomaly was seen to lie further out to sea today than would have been the case at the time of its construction, indicating an area of coastal erosion. In an attempt to understand this process, the marine and atmospheric forces acting on the area were examined. In association with the processes of coastal erosion, soil tests were undertaken to assess the nature of the material being eroded.
Using both historical and physiological evidence it was concluded that the anomaly was indeed a fish-trap, constructed at about the beginning of the 13th century. The results from the different avenues of study have shown a sea-level rise of about 2.84 m and a cliff recession of about 118 m since its construction.     

A Late Pleistocene coral fauna from Evans Head,N.S.W.

An assemblage of hermatypic scleractinian corals occurring landwards of the Pleistocene sandy Inner Barrier system has been referred to the last interglacial period. It comprises at least 20 species, many of which are in growth position, and is accompanied by a substantial association of molluscans. The richness of the assemblage is indicative of good access of oceanic waters at the time of its formation, so the deposit predates barrier emplacement. The coral occurrences are compared with present-day southern ranges of the scleractinian species (all extant), and the implications for climatic and sea-level conditions in the last interglacial are discussed. A sea-level stand of 4–6 m above that at present obtaining (in accord with Marshall & Thom, 1976) and a climatic shift towards a cooler regime equivalent to a minimum of 2° of latitude are concluded.     

POTENTIAL IMPACTS OF GLOBAL SEA-LEVEL RISE ON CANADIAN COASTS

The sea-level rise that may result from global climate change is placed within the context of past and present sea-level changes on Canadian coasts. To assess future impact, a dimensionless index of sensitivity is determined. Coasts with low, moderate, and high sensitivity constitute 67%, 30%, and 3% of the total coastline, respectively. The most sensitive regions are: (1) several parts of the Maritime Provinces; (2) two areas of the British Columbia coast; and (3) a large part of the Beaufort Sea coast. Impacts in four regions - Bay of Fundy, Beaufort Sea, Fraser Delta, and Eastern Shore of Nova Scotia - are discussed in detail. It is argued that the societal response to changes in sea level should favour retreat and accommodation strategies.
Il est possible que les changements climatiques globaux provoqueront une élévation du niveau de la mer. Nous examinons ce scénario dans le contexte des changements passés et présents du niveau de la mer sur les côtes canadiennes. Pour évaluer l'impact de l'élévation prévue un indice non dimensionnel de vulnérabilité est déterminé. Les côtes à la vulnérabilité basse, modérée et élevée constituent, respectivement, 67%, 30%, et 3% de tout le littoral. Les régions les plus vulnérables sont: (1) plusieurs régions dans les provinces maritimes; (2) deux zones sur la côte de la Colombie britannique; et (3) la plupart de la côte de la mer de Beaufort. Nous discutons en détail les impacts dans quatre régions, soit la baie Fundy, la mer Beaufort, la delta du Fraser et la rivage dit 'Eastern Shore' de la Nouvelle-Écosse. Nous estimons que la réponse sociale aux changements du niveau de la mer devrait favoriser des stratégies de retraite et d'accommodement.     

The dynamics of mangrove ecosystems,changes in sea level and the strategies of Neolithic settlements along the coast of Oman (6000–3000 cal. BC)

This paper focus on the Holocene palaeogeography of the Ja'alan coast from the 6th to the 4th millennium cal. BC, integrating the dynamics of mangroves, lagoons, khors-estuaries and deltas, with sea-level change and the evidence from Neolithic shell middens. The distribution and maturation of mangrove ecosystems along the Arabian coasts has varied considerably, affected by physical forces such as sea-level changes, climate, tidal amplitude and duration as well as the quantity of fresh water inflow associated with the monsoon systems along the Arabian coast. Palaeo-mangroves and lagoons, today replaced by large sabkhas, appear to be correlated to mid-Holocene fossil deltas and estuaries that currently function episodically, depending on the rhythm of winter rains. All these parameters have determined and impacted the location of settlement networks and the economic strategies of the first Arabian farmers along the eastern Arabian coast. The mid-Holocene sea-level highstand stability (5th millennium BC) can be considered to be an optimum period for mangrove development and can be correlated with Neolithic sites around the mangroves. The decline of mangroves since 3000/2500 cal. BC and further degradation is mainly attributed to the prevailing arid climate that reduced summer monsoon effects in the tropical area by favouring the extension of sabkhas. We discuss these aspects based on new archaeological surveys, excavations and geoarchaeological studies.     

Application of Quantitative Mineralogical Analysis in Archaeological Micromorphology: a Case Study from Barrow Is., Western Australia

This study assesses the use of the Tescan Integrated Mineral Analyser (TIMA) platform, which integrates scanning electron microscopy—energy dispersive spectroscopy (SEM-EDS) chemical analysis with mineral identification software, to quantitatively determine the mineralogical composition of sediments in archaeological research. Ten samples, spanning 50,000 years of sedimentation, were examined from archaeological excavation profiles in the Boodie Cave, Barrow Island, Western Australia. TIMA mineral abundance data show a gradual change from a polymineralogic quartz-rich assemblage from ~50–12 ka to a more simple carbonate-dominate assemblage from the terminal Pleistocene. This trend is consistent with a decreasing contribution of reworked terrestrial siliciclastic sediments derived from the mainland and an increase in carbonate sediments of marine derivation, as the exposed coastal plain become submerged during post-glacial sea-level rise. SEM-EDS analysis has also provided empirical data on cultural materials, mainly bone and shell fragments that similarly reflect the increasing contribution of marine fauna into the Holocene sediments. Particularly useful is the ability of mineral mapping function of the TIMA outputs to help distinguish 16 sub-units representing sections of the main nine stratigraphic units, including at least three contiguous midden events. The SEM-EDS data indicate that the redeposited sediments were derived from the overlying midden unit, with layering reflecting differential settling of mineral phases. This study demonstrates that automated mineralogy studies using TIMA can clearly aid the identification of provenance and processes within archaeological sediments and soils.     

Possible fossil impression in sandstone from the late Palaeoproterozoic-early Mesoproterozoic Semri Group (lower Vindhyan Supergroup), central India

The Lower–Middle Ordovician Zitai Formation of the South China palaeoplate consists of a succession of purple red, nodular argillaceous limestones. Palaeogeographically, it is distributed along the southeastern margin of the Yangtze Platform, and is of late Floian to Dapingian age, correlative with the Dawan Formation of the Middle and Lower Yangtze Platform. In Shitai County, Anhui Province, East China, the Zitai Formation is rich in conodonts, enabling the recognition of four biozones based on first appearance data. Detailed palaeontological and biostratigraphical study of these conodonts reveals that the Ordovician conodont radiation in the Lower Yangtze Platform attained its first diversity peak low in the Oepikodus evae Biozone. This diversification is generally consistent with macroevolutionary trends of brachiopods of South China and graptolites of the Upper Yangtze Platform, but was earlier than that of trilobites and acritarchs of the same palaeoplate. Correlation with the sea-level curve for South China suggests that conodont diversity change during the Ordovician radiation was mainly controlled by regional sea-level fluctuations.     

A Strategic Framework for Monitoring Coastal Change in Australia's Wet-dry Tropics – Concepts and Progress

A strategic framework for monitoring natural and human-induced change in the coastal plains of the Alligator Rivers Region in the wet-dry tropics of northern Australia is presented. The framework also supports refinement of methods used to monitor the vulnerability of coastal areas to change, including human-induced climate change and sea-level rise. The information derived through the framework can be used to assess scenarios, highlight the potential significance and implications of changes, and assist land managers formulate management responses. The framework incorporates several large-scale studies for monitoring atmospheric and hydrodynamic processes as well as mapping and monitoring projects specific to environmental change in the freshwater wetlands and the floodplains of the Region. Monitoring is proposed to address processes influencing the stability and rate of change of the floodplain environments. These include large-scale processes, such as inter-annual variability in weather conditions affecting the morphology of the coastal plains, shoreline and riverbank stabilisation, headward expansion of tidal creeks, and salinisation of freshwater basins. Information management is also addressed, and a Geographic Information System structure proposed for effective data collation, analysis and management. The information management system will facilitate data sharing and participation of multiple agencies and organisations interested in coastal change, especially where a landscape perspective or whole ecosystem approach is advocated.     

Refining Broad-Scale Vulnerability Assessment of Coastal Archaeological Resources,Lough Foyle,Northern Ireland

Increasing evidence indicates that ongoing and future climate change impacts, such as enhanced coastal erosion driven by intensified storms and sea-level rise, will be destructive or problematic for coastal archaeological heritage. Approaches to this problem range from broad-scale GIS-based vulnerability assessments to site-scale monitoring and survey. In all cases, the approach chosen should be based on the best-available data on the local historic environment and pattern of coastal change. Therefore, this paper will demonstrate how such data can be successively acquired and enhanced using an integrated approach that builds on and refines a previously conducted broad-scale vulnerability assessment. This approach was adopted in the study region (Northern Ireland) owing to a lack of coherent and up-to-date information on shoreline change. This approach incorporated the GIS-based Digital Shoreline Analysis System (DSAS) to quantify and analyze local shoreline change. DSAS is a software extension for ESRI ArcGIS which allows calculation of rate-of-change statistics using past shorelines identified from georeferenced historic maps and vertical aerial imagery. Additionally, a field survey was conducted to assess the condition of recorded sites, and identify unrecorded ones. Results revealed a more complex pattern of shoreline change in the study area (Magilligan Foreland, Lough Foyle) than previously anticipated, with zones of significant erosion interspersed with areas of stability or advance. Fifty-one new sites ranging from the prehistoric period to the Second World War were also identified. The new information was used to develop a priority classification based on site significance, condition and risk level which improved significantly on the uniform classification of the original broad-scale assessment.     

The Slate Quarries at Easdale,Argyllshire, Scotland

Abstract

In this article the author draws attention to the little-known slate industry that flourished in the Slate Islands off the west coast of Scotland. From small beginnings in the 17th century, the industry reached a peak around 1900, before declining to extinction in the 1960s. Attention is focused on the unusual location of some of the quarries—below sea-level—and of their consequent vulnerability to natural disasters.     

Luminescence dating of young coastal deposits from New Zealand using feldspar

A new measurement protocol has been tested on K-feldspars from Whanganui Inlet and Parengarenga Harbour, New Zealand. A Single Aliquot Regenerative (SAR) dose protocol, using two successive infrared (IR) stimulations (post-IR IR SAR protocol) is setup for these young (<1000 years) coastal sediments. Significant anomalous fading (g _2days =7 %/decade) is observed using the conventional IR signal measured at 50°C. In contrast, the fading rate of the IR signal measured at elevated temperature (150°C) after the IR stimulation at 50°C (a post-IR IR signal) is not significant (g _2days ≤ 1 %/decade). Surprisingly low residual infrared stimulated luminescence (IRSL) signals were observed for a surface sample, suggesting that accurate ages as young as ∼50 years can be obtained for these recent deposits. IRSL ages ranging between 48±6 years and 1050±50 years are obtained from six samples, indicating that sediment accumulation has occurred at the two sites during the last millennia, despite a falling trend in relative sea-level in Whanganui Inlet and a stable relative sea-level at Parengarenga Harbour.     

SahulTime: Rethinking Archaeological Representation in the Digital Age

SahulTime is an experimental development project to explore how archaeological knowledge might best be represented within a digitally native mode. The system incorporates an interactive, zoomable timeline with a changing geographic view, time-aware icons and detail-boxes that can themselves express temporal visualisations. The core knowledge domain currently represented is Australian archaeology in the context of changing sea-level, but the visualisation concepts developed are more generally applicable at a global level on all timescales, and may offer a first step towards the ‘Digital Earth’ vision of a top-down interface for exploring the world and its history.