Coastal Fringe Research Articles

KUALITAS PELAYANAN PUBLIK DI KANTOR CAMAT RUMBAI PESISIR

Public services at the district office coastal fringe. The quality of public services can be measured include the following elements: the turnaround time of service, details of fees or tariffs, procedures, facilities and infrastructure. In the implementation of public services in the district during the coastal fringe still constraints in implementing the four elements of the charter, because of the lack of openness to the public, although the sub-district officials had to undertake socialization activities that also involve the public. Although officially a maximum service is 15 minutes, the findings in the field expressed ketidaksusuaian with what has been set. The factors that affect the quality of services at the district office coastal fringe is: 1. Work Motivation bureaucracy and apparatus; 2. The ability of the apparatus; 3.pengawasan / social control; 4. The behavior of bureaucracy / apparatus; 5. Communication, disposition and bureaucratic structure and organizational communication climate and the flow of information; and 6. Restructuring the organization.

Total and extractable elemental composition of the intertidal estuarine biofilm of the Río de la Plata: Disentangling natural and anthropogenic influences

Estuarine transitional waters constitute regions affected by or at risk of anthropogenic impact due to urbanization and industrial development. The elemental composition of the intertidal biofilm sediment is an excellent marker for the detection of any impact, and may exert a bottom-up influence by natural concatenation to higher organization levels (e.g. molecules, cells, organisms, communities). The distribution pattern of elemental composition (total and bioavailable fraction) along the estuary axes was analyzed, disentangling potential shifts produced by human activities. We predict that most abundant elements in the Rio de la Plata estuary are the natural earth-crust components and that these will not show any evident gradient along the estuarine axis. Elements involved in human related processes will shape concentration gradients from the most probable source (i.e. cities) indicating estuarine pollution. The research strategy involved the sampling of intertidal biofilm along the entire estuary and the registration of environmental variables and the total and bioavailable elemental composition. Sampling sites represent pristine, agricultural, and urbanized areas along a 428-km-long coastline comprising the inner, middle and outer Río de la Plata estuarine zones and a coastal fringe of oceanic beaches of Uruguay (South America). Biofilm sediment samples were collected in Autumn 2011 and digested for total and extractable (bioavailable) elements quantification measured by ICP-OES. Mercury (Hg) sediments were digested with aqua regia and quantified by cold vapor atomic absorption (CVAAS). The most abundant elements measured were Al, Fe, and Ca in all sampling. Anthropogenic marker elements such as Hg, Cr, Pb, Zn, and Cu were found, even at potentially toxic levels, at urban beaches at the city of Montevideo. The ordination of samples highlights the distinctive characteristics of urban beaches, placed in a particular location along the first principal component. This position is mainly driven by human impact marker metals and C/N ratios. The results highlight the value of bioavailable elemental composition analyses of benthic biofilm as a tool for detecting shifts in estuarine systems.

Factors controlling groundwater salinization and hydrogeochemical processes in coastal aquifers from southern Spain.

In detrital coastal aquifers, seawater and surface water may interact with groundwater in multiple ways. Understanding the interference of water fluxes in this type of environment is essential to effectively manage the groundwater resources in water-stressed regions, such as the Mediterranean coastal fringe. In this research, the characterization of the main hydrogeochemical processes and the interaction between surface water and groundwater in the Marbella-Estepona coastal aquifers (southern Spain) have been carried out by means of the combined use of different hydrogeochemical indicators along with isotope data. The results show that the diversity of source lithologies (peridotite, carbonate and/or metapelitic) substantially conditions the groundwater geochemistry. The analysis of ionic deltas made it possible a preliminary screening of the geochemical reactions that occur in the Marbella-Estepona aquifers, while the Discriminant Analysis allowed for a consistent classification of sampled groundwater types. The dissolution of calcite and dolomite determines the chemical composition of the groundwater from the eastern sector that are more conditioned by the rainwater infiltration. The dissolution of magnesium-bearing minerals (predominantly forming peridotite rocks) is observed in groundwater samples from the western and central sectors, whose chemical composition showed a greater influence of surface water. The spatial analysis of rCl-/Br- in groundwater has permitted to corroborate that saline intrusion is negligible, hardly affecting to its original water quality. The irregularly distributed recharge by precipitation (seasonal effect) and the atmospheric circulation of cloud fronts (coastal/continental effect) explains why most of groundwater sampled is isotopically impoverished with respect to the rainfall signature. The isotope approach also suggests the hydraulic relationship between surface water and groundwater in the study site. A deeper knowledge of spatial hydrogeochemical variations in coastal groundwater and the influence of water sources over them are crucial for a sustainable groundwater management and global change adaptation in equivalent Mediterranean water-stressed regions.

Using large scale surveys to investigate seasonal variations in seabird distribution and abundance. Part II: The Bay of Biscay and the English Channel

Seabird distributions and the associated seasonal variations remain challenging to investigate, especially in oceanic areas. Recent advances in telemetry have provided considerable information on seabird ecology, but still exclude small species, non-breeding birds and individuals from inaccessible colonies from any scientific survey. To overcome this issue and investigate seabird distribution and abundance in the eastern North Atlantic (ENA), large-scale aerial surveys were conducted in winter 2011-12 and summer 2012 over a 375,000km2 area encompassing the English Channel (EC) and the Bay of Biscay (BoB). Seabird sightings, from 15 taxonomic groups, added up to 17,506 and 8263 sightings in winter and summer respectively, along 66,307km. Using geostatistical methods, density maps were provided for both seasons. Abundance was estimated by strip transect sampling. Most taxa showed marked seasonal variations in their density and distribution. The highest densities were recorded during winter for most groups except shearwaters, storm-petrels, terns and large-sized gulls. Subsequently, the abundance in winter nearly reached one million individuals and was 2.5 times larger than in summer. The continental shelf and the slope in the BoB and the EC were identified as key areas for seabird conservation, especially during winter, as birds from northern Europe migrate southward after breeding. This large-scale study provided a synoptic view of the seabird community in the ENA, over two contrasting seasons. Our results highlight that oceanic areas harbour an abundant avifauna. Since most of the existing marine protected areas are restricted to the coastal fringe, the importance of oceanic areas in winter should be considered in future conservation plans. Our work will provide a baseline for the monitoring of seabird distribution at sea, and could inform the EU Marine Strategy Framework Directive.

Plants show more flesh in the tropics: variation in fruit type along latitudinal and climatic gradients

Fruit type has a major impact on seed dispersal, seed predation and energy allocation, but our understanding of large‐scale patterns in fruit type variation is weak. We used a dataset of 4008 Australian species to provide the first continental‐scale tests of a series of hypotheses about the factors that might affect fruit type. We found a significant latitudinal gradient in the proportion of fleshy‐fruited species, with the percentage of fleshy‐fruited species rising from 19% at 43.75°S to 49% at 9.25°S. Species bearing fleshy fruits were more frequent on the coastal fringes of Australia, while species bearing non‐fleshy fruits became more frequent toward the arid centre. Wet, warm and stable climates favoured fleshy‐fruited species, with the two best predictors of the proportion of fleshy‐fruited species being maximum precipitation over five days (R2 = 0.40), and precipitation in the wettest month (R2 = 0.25). These results remained consistent after accounting for phylogenetic correlation among species. A combined model including variables of precipitation, temperature, and climatic variation explained 67% of the variation in the proportion of fleshy‐fruited species. Our results are consistent with the idea that plant reproductive strategies are more often tied to conditions during the parts of the year in which they grow than to conditions during the harsh parts of the year. Overall, our findings demonstrate strong relationships between plant reproductive traits and environmental gradients, and improve our understanding of the factors that shape large‐scale patterns in plant ecological strategies.

Decadal decline in demersal fish biomass coincident with a prolonged drought and the introduction of an exotic starfish

Between 1990 and 2011, Port Phillip Bay in southern Australia experienced 2 major ecological disturbances: a prolonged drought from 1997 to 2010, and the introduction of the invasive starfish, Asterias amurensis. The drought reduced land-based nitrogen inputs by 64%, and the biomass of A. amurensis in the deep centre of the bay peaked at 56% of the resident fish biomass in 2000. The impacts of these disturbances on fish were assessed using a demersal trawl time-series spanning 2 decades (1990 to 2011). The timing and spatial extent of changes to fish biomass were analysed using ANCOVA and change point analysis. During the drought, fish biomass declined by 69% in the deep centre of the bay, by 50% at intermediate depths, and showed no significant change around the shallow fringes. This spatial pattern is consistent with hydrodynamic modelling, which suggests that during the drought a greater proportion of the (lower) nitrogen input was retained near the coastal fringe. Most of the decline in fish biomass was attributed to the cumulative effects of reduced productivity during the 12 yr drought. However, declines in 3 species in the deep region were attributed to competition with A. amurensis. Each of these species exhibited high dietary overlap with A. amurensis and displayed sharp declines in biomass coinciding with the peak abundance of A. amurensis in 2000.

Disappearance of the New Moore Island from the Southernmost Coastal Fringe of the Sundarban Delta - A Case Study

Loss of two small estuarine islands, Lohachara and Suparibhanga has been reported earlier from the Indian Sundarban lying adjacent to the northern Bay of Bengal. The present paper reports the loss of another offshore island, New Moore, popularly known as Purbasha at the border of India and Bangladesh. The island came into existence after a cyclone in 1970. This study reveals the loss of New Moore Island within the time period of 1985 to 2000 from the analysis of multi-temporal satellite images. The rate of erosion, of two other offshore islands, Jambu Dwip (0.187 sq. km yr.−1) and Maya Dwip (0.508 sq. km yr.−1) situated along the same latitude of New Moore, were also estimated within the same time period. A close relationship was observed between the rate of erosion of small islands and the rate of rising sea level in this region as measured from the tide data at the Sagar Island and other observatories during the study period. The sea surface temperature analysis from the year 1990 to 1998 showed a slight increase (~ 0.8 °C increase), indicating the thermal expansion of the sea surface. Moreover, the sea surface height analyzed during the period 1993–2000 using satellite altimeter data of TOPEX/POSEIDON revealed a steady increase of 1.23 cm yr.−1 sea level acceleration.

Challenges in groundwater resource management in coastal aquifers of East Africa: Investigations and lessons learnt in the Comoros Islands, Kenya and Tanzania

Abstract Study region Coastal areas of Kenya (Kilifi County), Tanzania (Kilwa district) and Comoros (Ngazidja island), East Africa. Study focus Research aimed to understand the physical and societal drivers of groundwater accessibility and identify critical aspects of groundwater access and knowledge gaps that require further monitoring and research. Interdisciplinary societal, environmental and hydrogeological investigations were consistently undertaken in the three areas considered as exemplars of the diversity of the coastal fringes of the wider region. This paper focuses on the hydrogeological outcomes of the research, framed within the principal socio-environmental issues identified. New hydrological insights Results confirm the fundamental importance of coastal groundwater resources for the development of the region and the urgent need to match groundwater development with demographic and economic growth. Hydrogeological knowledge is fragmented, groundwater lacks a long-term monitoring infrastructure and information transfer from stakeholders to users is limited. Current trends in demography, climate, sea-level and land-use are further threatening freshwater availability. Despite possessing high-productivity aquifers, water quality from wells and boreholes is generally impacted by saltwater intrusion. Shallow large-diameter wells, following the traditional model of these areas, consistently prove to be less saline and more durable than deeper small-diameter boreholes. However, promoting the use of large numbers of shallow wells poses a significant challenge for governance, requiring coherent management of the resource at local and national scales and the engagement of local communities.

Estimation of deep infiltration in unsaturated limestone environments using cave lidar and drip count data

Abstract. Limestone aeolianites constitute karstic aquifers covering much of the western and southern Australian coastal fringe. They are a key groundwater resource for a range of industries such as winery and tourism, and provide important ecosystem services such as habitat for stygofauna. Moreover, recharge estimation is important for understanding the water cycle, for contaminant transport, for water management, and for stalagmite-based paleoclimate reconstructions. Caves offer a natural inception point to observe both the long-term groundwater recharge and the preferential movement of water through the unsaturated zone of such limestone. With the availability of automated drip rate logging systems and remote sensing techniques, it is now possible to deploy the combination of these methods for larger-scale studies of infiltration processes within a cave. In this study, we utilize a spatial survey of automated cave drip monitoring in two large chambers of Golgotha Cave, south-western Western Australia (SWWA), with the aim of better understanding infiltration water movement and the relationship between infiltration, stalactite morphology, and unsaturated zone recharge. By applying morphological analysis of ceiling features from Terrestrial LiDAR (T-LiDAR) data, coupled with drip time series and climate data from 2012 to 2014, we demonstrate the nature of the relationships between infiltration through fractures in the limestone and unsaturated zone recharge. Similarities between drip rate time series are interpreted in terms of flow patterns, cave chamber morphology, and lithology. Moreover, we develop a new technique to estimate recharge in large-scale caves, engaging flow classification to determine the cave ceiling area covered by each flow category and drip data for the entire observation period, to calculate the total volume of cave discharge. This new technique can be applied to other cave sites to identify highly focussed areas of recharge and can help to better estimate the total recharge volume.

Salinization process and coastal groundwater quality in Chaouia, Morocco

The coastal aquifer system of Chaouia is recognized as one of the most important aquifers in Morocco that is affected by salinization in the coastal fringe. The purpose of this study is to highlight the origin of salinization by sampling and analyzing groundwater from 44 wells for major elements. This study was carried out in May 2011. The results indicate that, in the central and downstream parts, the dominant facies are Mg2+, Na+ and Cl−, while Ca2+ and HCO3− dominate in the upstream zones. Ion exchange processes, under seawater intrusion, control the concentration of ions such as calcium, magnesium and sodium. Moreover, groundwater is oversaturated with respect to carbonate minerals (calcite and dolomite), and under-saturated with respect to evaporate minerals (gypsum, halite). The contribution of dissolved halite and gypsum in the groundwater mineralization is revealed by their positive correlation between (Na + Cl) and (Ca + SO4), respectively. Furthermore, the comparison of the hydrochemical results to drinking water quality standards by World Health Organization (2008) shows that more than a half of the water sampled is not suitable for drinking purposes, especially with respect to high levels of EC, TDS, Cl− and NO3−. In addition, high mineralization is found to be a consequence of seawater intrusion and anthropogenic activities.

Interaction between spawning habitat and coastally steered circulation regulate larval fish retention in a large shallow temperate bay

Larval retention plays a fundamental role in the persistence of coastal fish assemblages. Here, we examine larval fish distribution and abundance patterns in Palma Bay, a large (∼20 km) wind-driven microtidal bay in the southern coast of Mallorca (Spain, NW Mediterranean Sea). Larval fish assemblage structure in the bay were analyzed during July 2010 and interpreted in the context of the observed circulation patterns, adult habitat distribution and spawning traits. Acoustic Doppler Current Profiler (ADCP) observations showed the presence of retentive flow patterns in the middle of the bay enhancing local larval accumulation and self-recruitment. In consequence, larval abundances were higher in this central part of the bay (∼40 m depth, mean abundance 607.6 ± 383 ind. 10 m−2) than along the coastal fringe (<35 m 113.7 ± 91 ind. 10 m−2). Also, a multivariate predictive approach based on Redundancy Analysis (RDA) revealed differences between the larval fish assemblages in areas inside the bay, constituted by small pelagic and benthopelagic taxa (gobids, Chromis chromis and Serranus hepatus) and offshore larvae, mostly from meso and large pelagic fish. These larval fish assemblages were structured according to depth variations and zooplankton abundance, and remained relatively unmixed because of the circulation patterns in the mouth of the bay that uncouple its dynamics from alongshelf circulation. Even larvae of typically pelagic species that spawn close to the coast (Sardinella aurita, Auxis rochei) were associated with the retentive effect of the bay. Our study highlights the important role of coastal bays in the regulation of coastal fish population dynamics and as hotspots for the maintenance of diversity in the Mediterranean Sea.

Assessing relative vulnerability to sea-level rise in the western part of the Mekong River Delta in Vietnam

The Mekong River Delta in Vietnam plays a crucial role for the region in terms of food security and socioeconomic development; however, it is one of the most low-lying and densely populated areas in the world. It is vulnerable to seawater incursion, flood risk, and shoreline change, exacerbated as a consequence of sea-level rise (SLR) related to climate change. This study examined the Kien Giang coast in the western part of the delta, comprising seven coastal districts (namely Ha Tien, Kien Luong, Hon Dat, Rach Gia, Chau Thanh, An Bien, and An Minh), the economy of which is important in terms of agriculture and aquaculture. The analytical hierarchical process (AHP) method of multi-criteria decision making was integrated directly into geographic information systems (GIS) to derive a composite vulnerability index that indicated areas most likely to be vulnerable to SLR. The hierarchical structure comprised three key components: exposure (E), sensitivity (S), and adaptive capacity (A), at level 1. At the next level, 8 sub-components were mapped: seawater incursion, flood risk, shoreline change, population characteristics, land use/land cover, and socioeconomic, infrastructure, and technological capability, beyond which a further 22 variables (level 3) and 24 sub-variables (level 4) related to vulnerability were also mapped. Variables were assigned weights for incorporation into AHP pairwise comparisons after discussion with stakeholders. Maps were generated to visualise areas where the relative vulnerability was very low, low, moderate, high, and very high. Societal data were generally only available at district level; however, several regional patterns emerged. Relatively high exposure to flooding and inundation, salinity, and moderate loss of mangroves occurred along the coastal fringe of each district. This western section of the delta, which is low-lying and remote from the distributaries that carry sediment to the coast, appears to be particularly vulnerable. The most sensitive areas tended to be ethnic households engaged in rice cultivation and with moderate population density. The least adaptable areas consisted of high numbers of poor households, with low income, and moderate densities of transport, irrigation and drainage systems. Most coastal districts were determined to be moderately to relatively highly vulnerable, with scattered hotspots along the coast.

Influence of Grain Size on Burrowing and Alongshore Distribution of the Yellow Clam (Amarilladesma mactroides)

ABSTRACT The yellow clam Amarilladesma mactroides (Reeve, 1854), is an intertidal species that prospers mainly on dissipative sandy beaches along the temperate Atlantic coast of South America, from Brazil to Argentina (24–41° S). This large clam is considered a fast burrower, which lives buried in the sediment, migrating seasonally into the intertidal zone. The present study explores the effect of sediment grain size on the burrowing performance of this species, to elucidate the influence of granulometry on the alongshore distribution of the A. mactroides population. Laboratory trials were performed with clams of different sizes, to study the influence of grain size on the burial rate. Clam distribution was analyzed along a 32 km coastal fringe whose granulometric composition varies from very fine to coarse sand. The values of the mean burrowing rate index, a measurement of clam mobility, suggest that burrowing is fast to very fast in fine and medium sand and becomes slower toward areas with extreme parti...

Malpighia meyeriana(Malpighiaceae), a new species from the NE coast of Cuba

González Gutiérrez P. A.: Malpighia meyeriana (Malpighiaceae), a new species from the NE coast of Cuba [Novitiae florae cubensis 49]. — Willdenowia 45: 443–447. 2015. — Version of record first published online on 16 November 2015 ahead of inclusion in December 2015 issue; ISSN 1868-6397; © 2015 BGBM Berlin.DOI: http//dx.doi.org/10.3372/wi.45.45311Malpighia meyeriana, a new species from the NE coastal fringe of Cuba, is described and compared with other species of the genus occurring in Cuba. Aspects of its distribution and conservation status are discussed.

Spatial distribution of precipitation annual cycles over South Africa in 10 CORDEX regional climate model present-day simulations

This study presents an evaluation of the ability of 10 regional climate models (RCMs) participating in the COordinated Regional climate Downscaling Experiment-Africa to reproduce the present-day spatial distribution of annual cycles of precipitation over the South African region and its borders. As found in previous studies, annual mean precipitation is quasi-systematically overestimated by the RCMs over a large part of southern Africa south of about 20°S and more strongly over South Africa. The spatial analysis of precipitation over the studied region shows that in most models the distribution of biases appears to be linked to orography. Wet biases are quasi-systematic in regions with higher elevation with inversely neutral to dry biases particularly in the coastal fringes. This spatial pattern of biases is particularly obvious during summer and specifically at the beginning of the rainy season (November and December) when the wet biases are found to be the strongest across all models. Applying a k-means algorithm, a classification of annual cycles is performed using observed precipitation data, and is compared with those derived from modeled data. It is found that the in-homogeneity of the spatial and temporal distribution of biases tends to impact the modeled seasonality of precipitation. Generally, the pattern of rainfall seasonality in the ensemble mean of the 10 RCMs tends to be shifted to the southwest. This spatial shift is mainly linked to a strong overestimation of convective precipitation at the beginning of the rainy season over the plateau inducing an early annual peak and to an underestimation of stratiform rainfall in winter and spring over southwestern South Africa.

Variations in macrobenthic community structure in relation to changing environmental conditions in sandy beaches of Argentina

This study describes for the first time the intertidal macrobenthic community of exposed sandy beaches located near the Bahía Blanca Estuary (38°S) and reports the physical characterization of this coastal fringe. The main objective of the study was to link environmental variables to biotic information, analyzing the results in the context of the Swash Exclusion Hypothesis (SEH) and possible estuarine influence. Four beaches were sampled seasonally at different distances from the mouth of the Bahía Blanca Estuary. To characterize the morphodynamic state of the beaches, the Dean parameter (Ω) was calculated. Multivariate analyses were used to assess benthic community structures and their relationships with physical variables. The two beaches located closest to the Bahía Blanca Estuary were classified as intermediate and those located further from the estuary as dissipative. Richness, diversity and biomass of intertidal macrobenthic communities varied with the SEH, increasing towards the dissipative beaches. However, total density was higher on intermediate beaches, possibly because of nutrient-rich silt-clay sediment input from the estuary, enabling them to maintain a higher density of organisms than dissipative beaches. The estuary acts as a moderator of habitat hardness, which together with the morphodynamic state of the beaches is an important factor in the structuring of the macrobenthic community along this coastal fringe.

Habitat segregation and ecological character displacement in cryptic African malaria mosquitoes.

Understanding how divergent selection generates adaptive phenotypic and population diversification provides a mechanistic explanation of speciation in recently separated species pairs. Towards this goal, we sought ecological gradients of divergence between the cryptic malaria vectors Anopheles coluzzii and An. gambiae and then looked for a physiological trait that may underlie such divergence. Using a large set of occurrence records and eco-geographic information, we built a distribution model to predict the predominance of the two species across their range of sympatry. Our model predicts two novel gradients along which the species segregate: distance from the coastline and altitude. Anopheles coluzzii showed a ‘bimodal’ distribution, predominating in xeric West African savannas and along the western coastal fringe of Africa. To test whether differences in salinity tolerance underlie this habitat segregation, we assessed the acute dose–mortality response to salinity of thirty-two larval populations from Central Africa. In agreement with its coastal predominance, Anopheles coluzzii was overall more tolerant than An. gambiae. Salinity tolerance of both species, however, converged in urban localities, presumably reflecting an adaptive response to osmotic stress from anthropogenic pollutants. When comparing degree of tolerance in conjunction with levels of syntopy, we found evidence of character displacement in this trait.

Evaluation of groundwater mineralization processes and seawater intrusion extension in the coastal aquifer of Oualidia, Morocco: hydrochemical and geophysical approach

Oualidia city is located on the Moroccan Atlantic coast. Groundwater is the only resource for agriculture irrigation in this area. This operation is done by intensive pumping mainly in the coastal fringe. In this study, hydrochemical and geophysical methods were conducted to evaluate both composition and processes which control groundwater mineralization in Oualidia. For this purpose, 19 samples of groundwater were analyzed in major ions. The results showed that the mineralization is mainly due to sea water intrusion, especially in the first kilometer over the ocean, with abundance of Na+ (651.3 mg/l on average) and Cl− ions (1,425 mg/l on average). Beyond this fringe, 1 km, the mineralization is low, with an abundance of calcium (190.4 mg/l on average) and bicarbonate (241.1 mg/l on average) indicating the rock nature effect. Data interpretation from six profiles of electrical resistivity tomography (ERT), performed in the region, has led to detect seawater intrusion extension. The level assigned to the marine effect is characterized by a resistivity lower than 30 Ω m. Moreover, hydrochemical and geophysical studies were provided information on the mineralization extension in the aquifer of this zone, which is limited to 1 km from the ocean.

The exposure of Sydney (Australia) to earthquake-generated tsunamis, storms and sea level rise: a probabilistic multi-hazard approach.

Approximately 85% of Australia's population live along the coastal fringe, an area with high exposure to extreme inundations such as tsunamis. However, to date, no Probabilistic Tsunami Hazard Assessments (PTHA) that include inundation have been published for Australia. This limits the development of appropriate risk reduction measures by decision and policy makers. We describe our PTHA undertaken for the Sydney metropolitan area. Using the NOAA NCTR model MOST (Method for Splitting Tsunamis), we simulate 36 earthquake-generated tsunamis with annual probabilities of 1:100, 1:1,000 and 1:10,000, occurring under present and future predicted sea level conditions. For each tsunami scenario we generate a high-resolution inundation map of the maximum water level and flow velocity, and we calculate the exposure of buildings and critical infrastructure. Results indicate that exposure to earthquake-generated tsunamis is relatively low for present events, but increases significantly with higher sea level conditions. The probabilistic approach allowed us to undertake a comparison with an existing storm surge hazard assessment. Interestingly, the exposure to all the simulated tsunamis is significantly lower than that for the 1:100 storm surge scenarios, under the same initial sea level conditions. The results have significant implications for multi-risk and emergency management in Sydney.

A glacial cryptic refuge in south‐east Australia: human occupation and mobility from 36 000 years ago in the Sydney Basin, New South Wales

ABSTRACTExcavations across a source‐bordering dune overlooking the Hawkesbury River in north‐west Sydney, Australia, suggest initial occupation of the region by at least 36 ka, with variable but uninterrupted use until the early Holocene; following abandonment, the site was then re‐occupied by ∼3 ka. Along with a handful of other sites, the results provide the earliest reliable evidence of permanent regional populations within south‐eastern Australia, and support a model in which early colonizers followed the coastal fringe with forays along the main river systems. The evidence is consistent with the demographic model of Williams, 2013 (Proceedings of the Royal Society Series B 280: 20130486), which suggested low, but established regional populations before the Last Glacial Maximum (LGM), a population nadir following the LGM and increasing use of the region from ∼12 to 8 ka. The site exhibits increased use at the onset and peak of the LGM, and provides an example of a cryptic refuge as defined by Smith, 2013 (The Archaeology of Australia's Deserts. Cambridge University Press: New York). Specifically, changing artefact densities and attributes show the site was used repeatedly, but for shorter periods through this time, and suggest it formed one of a series of key localities in a point‐to‐point (rather than home‐base) subsistence strategy. This strategy was maintained until the site's abandonment in the early Holocene, despite changing population and climatic conditions through the Terminal Pleistocene.