Decade-scale coastal bluff retreat from LiDAR data: Lake Erie coast of NW Pennsylvania, USA

Bluff retreat is an ongoing problem on the southern Great Lakes coast of the United States where Pleistocene unconsolidated sediments overlie Devonian bedrock. This retreat results in loss of sediment from the coastal zone and a decrease in coastal water quality, and is of concern because evaluating landslide hazards and developing regulations on coastal construction setbacks must account for spatial variability in coastal retreat. The goal of this pilot study is to explain and quantify short to medium term spatial variability in bluff-retreat patterns, magnitudes, and rates along a 6 km littoral cell on the Pennsylvania coast of Lake Erie. High-resolution LiDAR data covering a one-decade time frame (1998–2007) permit mapping of the bluff-crest position on two comparable, high-quality data sets. The rates of bluff retreat range from unresolvable (~20% of coast) to 2.2 m/year, averaging 0.22 ± 0.1 m/year. Average-annual change rates and 9-year net movement values show an along-coast periodicity, with a spatial wavelength of ~1 km and an amplitude of 0.2 m/year. Observed variability is inferred to occur because variations in surface watershed size and groundwater recharge area, topographic shielding of the bluff from overland flow, and groundwater-table topography, cause groundwater discharge and overland flow to the bluff face to vary along the coast. In addition, short ravines (<300 m in length) fed by groundwater seepage distort groundwater equipotential lines and cause locally enhanced bluff retreat. While other factors likely influence bluff retreat spatially along this coast, their roles are relatively minor at the scale of this study.     

Mapping Shoreline Variability of Two Barrier Island Segments Along the Florida Coast

Recent projections of global climate change necessitate improved methodologies that quantify shoreline variability. Updated analyses of shoreline movement provide important information that can aid and inform likely intervention policies. This paper uses the Analyzing Moving Boundaries Using R (AMBUR) technique to evaluate shoreline change trends over the time period 1856 to 2015. Special emphasis was placed on recent rates of change, during the 1994 to 2015 period of active storm conditions. Small segments, on the order of tens of kilometers, along two sandy barrier island regions on Florida’s Gulf and Atlantic coasts were chosen for this study. The overall average rate of change over the 159-year period along Little St. George Island was ??0.62?±?0.12 m/year, with approximately 65% of shoreline segments eroding and 35% advancing. During periods of storm clustering (1994–2015), retreat rates along portions of this Gulf coast barrier accelerated to ??5.49?±?1.4 m/year. Along the northern portion of Merritt Island on Florida’s Atlantic coast, the overall mean rate of change was 0.22?±?0.08 m/year, indicative of a shoreline in a state of relative dynamic equilibrium. In direct contrast with the Gulf coast shoreline segment, the majority of transects (65%) evaluated along the oceanfront of Merritt Island over the long term displayed a seaward advance. Results indicate that episodes of clustered storm activity with fairly quick return intervals generally produce dramatic morphological alteration of the coast and can delay natural beach recovery. Additionally, the data show that tidal inlet dynamics, shoreline orientation, along with engineering projects, act over a variety of spatial and temporal scales to influence shoreline evolution. Further, the trends of shoreline movement observed in this study indicate that nearshore bathymetry—the presence of shoals—wields some influence on the behavior of local segments of the shoreline.     

An analysis of beach profile changes subsequent to the Colombo Harbor Expansion Project,Sri Lanka

Man-made coastal structures directly affect sediment balance and sediment dynamics on the surrounding beaches. The Colombo Harbor Expansion Project has created about 5-km-long breakwater nearly perpendicular to the beach. The present study is focused on quantitatively and qualitatively analyzing the effect of the Colombo Harbor Expansion Project on economically important beaches in and around Colombo city area. In this study, the authors measured monthly variations of beach width, beach profile and the mean grain-size of the sediments at mean sea level for complete annual monsoon cycle. Data were analyzed to establish site-specific erosion vulnerability. Monitoring results show that cumulative beach erosion has increased after the construction of the breakwater (rate = 0.7 m/year from May 2000 to April 2011 and rate = 28.2 m/year from April 2011 to June 2012). In addition, the cumulative and site-specific sand accretion and erosion patterns have a clear relationship with the monsoon seasonality. Beaches were narrower during the stormy southwestern monsoon, whereas beaches were wider during fair weather of northeast monsoon and inter-monsoon periods. In contrast, the constructed breakwater obstructs natural longshore sediment dynamics. For example, a significant amount of sediments from the Kelani-Ganga River were buried in the Colombo Harbor due to alteration of prominent longshore sediments transportation on the western coast of Sri Lanka. Therefore, this study shows enhancement of coastal erosion in the studied southern beaches due to a lack of sediment deposition.     

The Arctic Coastal Dynamics Database: A New Classification Scheme and Statistics on Arctic Permafrost Coastlines

Arctic permafrost coasts are sensitive to changing climate. The lengthening open water season and the increasing open water area are likely to induce greater erosion and threaten community and industry infrastructure as well as dramatically change nutrient pathways in the near-shore zone. The shallow, mediterranean Arctic Ocean is likely to be strongly affected by changes in currently poorly observed arctic coastal dynamics. We present a geomorphological classification scheme for the arctic coast, with 101,447?km of coastline in 1,315 segments. The average rate of erosion for the arctic coast is 0.5?m? year^?1 with high local and regional variability. Highest rates are observed in the Laptev, East Siberian, and Beaufort Seas. Strong spatial variability in associated database bluff height, ground carbon and ice content, and coastline movement highlights the need to estimate the relative importance of shifting coastal fluxes to the Arctic Ocean at multiple spatial scales.     

Drainage patterns in southeast Queensland: the key to concealed geological structures?

Southeast Queensland's geomorphology is characterised by northwest – southeast-trending trunk drainage channels and highlands that strongly correlate with the distribution of geological units and major faults. Other geomorphological trends strongly coincide with subsidiary faults and geological domains. Australia is presently under compressional stress. Seismicity over the past 130 years records 56 earthquakes of >2 magnitude indicating continuing small-scale earth movements in the Moreton region. Highlands in this region are dominated by Paleozoic to Triassic metamorphic and igneous rocks, and are generally 20 – 80 km from the coastline. Coastal lowlands are largely dominated by Mesozoic sedimentary basins and a veneer of surficial sediments. The eastern coast of Australia represents a passive margin; crustal sag along this margin could be expected to produce relatively short, high-energy, eastward-flowing drainage systems. We performed a geomorphological analysis to characterise the drainage patterns in southeast Queensland and identify associations with geological features. Anomalous channel, valley and escarpment features were identified, which failed to match the anticipated drainage model and also lacked obvious geological control. Despite their proximity to the coast (base level), these features include areas where drainage channels flow consistently away from, or parallel to, the coastline. Although many channels do coincide with geological structures, the drainage anomalies cannot be directly related to known structural discontinuities. Anomalous drainage patterns are suggested to indicate previously unidentified structural features and in some cases relatively young tectonic control on the landscape. Recent seismicity data have also been analysed to assess spatial correlations between earthquakes and geomorphological features. Our results show that structure largely controls drainage patterns in this region, and we suggest that a presently unmapped and potentially active, deep-seated structure may exist parallel to the coast in the northern coastal region. We propose that this structure has been associated with uplift in the coastal region of southeast Queensland since mid-Cenozoic times.     

Response of west Indian coastal regions and Kavaratti lagoon to the November-2009 tropical cyclone Phyan

Response of the coastal regions of eastern Arabian Sea (AS) and Kavaratti Island lagoon in the AS to the tropical cyclonic storm `Phyan??, which developed in winter in the south-eastern AS and swept northward along the eastern AS during 9?C12 November 2009 until its landfall at the northwest coast of India, is examined based on in situ and satellite-derived measurements. Wind was predominantly south/south-westerly and the maximum wind speed (U<sub>10</sub>) of ~16 m/s occurred at Kavaratti Island region followed by ~8 m/s at Dwarka (Gujarat) and ~7 m/s at Diu (located south of Dwarka) as well as two southwest Indian coastal locations (Mangalore and Malpe). All other west Indian coastal sites recorded maximum wind speed of ~5?C6 m/s. Gust factor (i.e., gust-to-speed ratio) during peak storm event was highly variable with respect to topography, with steep hilly stations (Karwar and Ratnagiri) and proximate thick and tall vegetation-rich site (Kochi) exhibiting large values (~6), whereas Island station (Kavaratti) exhibiting ~1 (indicating consistently steady wind). Rainfall in association with Phyan was temporally scattered, with the highest 24-h accumulated precipitation (~60 mm) at Karwar and ~45 mm at several other west Indian coastal sites. Impact of Phyan on the west Indian coastal regions was manifested in terms of intensified significant waves (~2.2 m at Karwar and Panaji), sea surface cooling (~5°C at Calicut), and moderate surge (~50 cm at Verem, Goa). The surface waves were south-westerly and the peak wave period (T <sub>p</sub>) shortened from ~10?C17 s to ~5?C10 s during Phyan, indicating their transition from the long-period `swell?? to the short-period `sea??. Reduction in the spread of the mean wave period (T _z) from ~5?C10 s to a steady period of ~6 s was another manifestation of the influence of the cyclone on the surface wave field. Several factors such as (1) water piling-up at the coast supported by south/south-westerly wind and seaward flow of the excess water in the rivers due to heavy rains, (2) reduction of piling-up at the coast, supported by the upstream penetration of seawater into the rivers, and (3) possible interaction of upstream flow with river run-off, together resulted in the observed moderate surge at the west Indian coast. Despite the intense wind forcing, Kavaratti Island lagoon experienced insignificantly weak surge (~7 cm) because of lack of river influx and absence of a sufficiently large land boundary required for the generation and sustenance of wave/wind-driven water mass piling-up at the land?Csea interface.     

Availability of coastal groundwater discharge as an alternative water resource in a large-scale reclaimed land,Korea

This study was conducted to identify the availability of coastal groundwater discharge (CGD), subsurface fluids flowing from inland through the coastal area to sea, as an alternative water resource for a large-scale reclaimed land. The behaviors of stable isotopes indicated that groundwater originated from inland precipitation and traveled as CGD along the coast line. Most of the groundwater samples collected from domestic wells installed along the old coast line were considered to be relatively fresh from the correlation analysis among chemical constituents. The average electrical conductivity (EC) values of the samples were identified as averaging 1,125–1,297 μS cm^?1, corresponding to appropriate crop growth. A weathered-rock layer in a small catchment within the reclaimed land was proved to be a main CGD pathway, with electrical resistivity anomalies ranging from 7 to 14 Ω m. Five monitoring wells were placed in this catchment to delineate the occurrence of CGD. Long-term vertical EC profiling results for the monitoring wells indicated that CGD occurs within a depth of 30 m below the ground surface. Annual monitoring data for groundwater level and EC demonstrated that the water quality of CGD was improved by introducing fresh terrestrial groundwater. A remarkable improvement in water quality (EC decrease of 900–1,600 μS cm^?1) of CGD was observed during the saline water pumping test that explains how CGD could be an alternative water resource for the reclaimed land.     

Erosion and Flooding—Threats to Coastal Infrastructure in the Arctic: A Case Study from Herschel Island,Yukon Territory,Canada

Arctic coastal infrastructure and cultural and archeological sites are increasingly vulnerable to erosion and flooding due to amplified warming of the Arctic, sea level rise, lengthening of open water periods, and a predicted increase in frequency of major storms. Mitigating these hazards necessitates decision-making tools at an appropriate scale. The objectives of this paper are to provide such a tool by assessing potential erosion and flood hazards at Herschel Island, a UNESCO World Heritage candidate site. This study focused on Simpson Point and the adjacent coastal sections because of their archeological, historical, and cultural significance. Shoreline movement was analyzed using the Digital Shoreline Analysis System (DSAS) after digitizing shorelines from 1952, 1970, 2000, and 2011. For purposes of this analysis, the coast was divided in seven coastal reaches (CRs) reflecting different morphologies and/or exposures. Using linear regression rates obtained from these data, projections of shoreline position were made for 20 and 50 years into the future. Flood hazard was assessed using a least cost path analysis based on a high-resolution light detection and ranging (LiDAR) dataset and current Intergovernmental Panel on Climate Change sea level estimates. Widespread erosion characterizes the study area. The rate of shoreline movement in different periods of the study ranges from ?5.5 to 2.7 m·a^?1 (mean ?0.6 m·a^?1). Mean coastal retreat decreased from ?0.6 m·a^?1 to ?0.5 m·a^?1, for 1952–1970 and 1970–2000, respectively, and increased to ?1.3 m·a^?1 in the period 2000–2011. Ice-rich coastal sections most exposed to wave attack exhibited the highest rates of coastal retreat. The geohazard map combines shoreline projections and flood hazard analyses to show that most of the spit area has extreme or very high flood hazard potential, and some buildings are vulnerable to coastal erosion. This study demonstrates that transgressive forcing may provide ample sediment for the expansion of depositional landforms, while growing more susceptible to overwash and flooding.     

Tectonic Subsidence of California Estuaries Increases Forecasts of Relative Sea-Level Rise

Even along the generally uplifting coast of the Pacific US, local geologic structures can cause subsidence. In this study, we quantify Holocene-averaged subsidence rates in four estuaries (Carpinteria Slough, Goleta Slough, Campus Lagoon, and Morro Bay) along the southern and central California coast by comparing radiocarbon-dated estuarine material to a regional sea-level curve. Holocene-averaged rates of vertical motion range from subsidence of 1.4?±?2.4, 1.2±0.4, and 0.4?±?0.3 mm/year in Morro Bay, Carpinteria Slough, and Goleta Slough, respectively, to possible uplift in Campus Lagoon (?0.1?±?0.9 mm/year). The calculated rates of subsidence are of the same magnitude as rates of relative sea-level rise experienced over the late Holocene and effectively double the ongoing rates of relative sea-level rise experienced over the last five decades on other parts of the coast. The difference in rates of vertical motion among these four estuaries is attributed to their geological settings. Estuaries developed in subsiding geological structures such as synclines and fault-bounded basins are subsiding at much higher rates than those developed within flooded river valleys incised into marine terraces. Restoration projects accounting for future sea-level rise must consider the geologic setting of the estuaries and, if applicable, include subsidence in future sea-level rise scenarios, even along the tectonically uplifting US Pacific Coast.     

Sinkhole formation and subsidence along the Dead Sea coast,Israel

More than 4,000 sinkholes have formed since the 1980s within a 60-km-long and 1-km-wide strip along the western coast of the Dead Sea (DS) in Israel. Their formation rate accelerated in recent years to >400 sinkholes per year. They cluster mostly in specific sites up to 1,000 m long and 200 m wide, which align parallel to the general direction of the fault systems associated with the DS Rift. The abrupt appearance of the sinkholes reflects changes to the groundwater regime around the shrinking DS. The eastward retreat of the shoreline and the lake-level drop (1 m/year in recent years) cause an eastward and downward migration of the fresh/saline groundwater interface. Consequently, a subsurface salt layer, which was previously enveloped by saline groundwater, is gradually being invaded and submerged by relatively fresh groundwater, and cavities form due to the rapid dissolution of the salt. Collapse of the overlying sediments into these cavities results in sinkholes at the surface. An association between sinkhole sites and land subsidence is revealed by interferometric synthetic aperture radar (InSAR) measurements. On a broad scale (hundreds of meters), subsidence occurs due to compaction of fine-grained sediments as groundwater levels decline along the retreating DS shoreline. At smaller scales (tens of meters), subsidence appears above subsurface cavities in association with the sinkholes, serving in many cases as sinkhole precursors, a few weeks to more than a year before their actual appearance at the surface. This paper overviews the processes of sinkhole formation and their relation to land subsidence.     

Long-and short-term variations in shore morphology of Van Island in gulf of Mannar using remote sensing images and DSAS analysis

Trends of shoreline changes need a scientific study as erosion affects the coastal ecosystem and environment. This study focuses on the trends of shoreline changes along the Van Island, Gulf of Mannar, during the period from 2000 to 2016 using the Digital Shoreline Analysis System model of a tool in Arc Map. Shorelines were extracted from the Landsat OLI and ETM+ satellite data from the years 2000, 2005, 2010 and 2015 and short-term changes obtained by TSS with the help of GPS. The rates of changes were calculated by the standard method of end point rate based on 157 transects lines and baseline. The average value of EPR observed was ?5.03 m/year during the study period. Statistics of EPR further calculated the average long-time intervals during the period of 15 years and also short-term changes. It is noted that the study area of Van Island’s degradation is very rapid. The analysis shows that the surveyed years from 2015 to 2016 record the highest erosion and retreat of shoreline changes in December 2014 to May2015 than in May2015 to December 2015. Based on the predicted EPR value of ?125 m/year of erosion in the next 25 years, it is concluded that the Van Island will vanish.     

Coastal Wetlands of China: Changes from the 1970s to 2007 Based on a New Wetland Classification System

A new classification of coastal wetlands along the coast of China has been generated that is compatible with the Ramsar Convention of 1971. The coastal wetlands have been divided into two broad categories with overall nine subcategories. On this basis, a series of coastal wetland maps, together covering the coast of mainland China, have been produced based on topographic maps acquired in the 1970s and satellite images acquired in 2007. These document substantial wetland losses over this period. In the 1970s, the total coastal wetland area in China was 5.76?×?10⁴?km², whereas in 2007, it was 5.36?×?10⁴?km², indicating a loss of 7 %. Over this approximately 40-year period, the area of natural coastal wetlands decreased from 5.74?×?10⁴ to 5.09?×?10⁴?km², while that of artificial coastal wetlands increased from 240 to 2,740 km². Due to shoreline and sea-level changes, newly formed coastal wetlands amounted to 2,460 km², while coastal wetland loss amounted to 6,310 km² in the period from the 1970s to 2007. When excluding shallow coastal waters (depths between 0 and ?5 m), nearly 16 % of Chinese coastal wetlands have been lost between the 1970s and 2007.     

Indirect economic losses of drought under future projections of climate change: a case study for Spain

This study presents the results of numerical simulations of the 2004 Indian Ocean earthquake and tsunami in the Bay of Lhok Nga (northwestern coast of Sumatra, Indonesia) integrating sediment erosion and deposition. We investigate the transport of sediment both by suspension and by bedload under different scenarii of long breaking dispersive waves through a series of numerical experiments. The earthquake source model used by Koshimura et al. (Coast Eng J 51:243–273, 2008) with a 25-m dislocation better reproduces the wave travel time, flow depth and inundation area than the other models tested. The model reproduces realistically the pronounced coastal retreat in the northern part of Lhok Nga Bay (retreat ranging between 50 and 150 m), where Paris et al. (Geomorphology 104:59–72, 2009) estimated a mean retreat of 80 m. There is also a good agreement between the simulated area of coastal retreat (195,400 m²) and the field observations (203,200 m²). The simulation may underestimate the volume of tsunami deposits (611,700 m³ vs. 500,000–1,000,000 m³ estimated by Paris et al. (2009). The model fully reproduces the observed thickness of tsunami deposits when considering both bedload and suspension, even if bedload transport dominates. Limitations are due to micro-scale topographic, anthropic features (which are not always represented by the DEM) and the amount of debris which may influence flow dynamics and sediment transport.     

Tidal controls on coastal groundwater conditions: field investigation of a macrotidal system

Previous studies of coastal groundwater resources have not properly explored the hydraulic conditions at coastal and estuarine boundaries, despite recognised influences of oceanic and estuarine water-level fluctuations (e.g. tides and waves) on groundwater near these boundaries. Such influences may have important implications for determining submarine groundwater discharge and seawater intrusion. In this paper, oceanic and estuarine controls on the hydrology of coastal aquifers are characterised for a macrotidal system—the Pioneer Valley coastal plain, northeastern Australia. The tidal water-table over-height (tide-induced increase in average water-table height at the coastline) is quantified at three locations and compared with theoretical estimates, which assume simplified physiographical conditions compared with those encountered at the field sites. The results indicate that local geological conditions, beach morphology and characteristics of tidal forcing control the behaviour of nearshore groundwater within the system. Existing analytical and numerical solutions that are commonly applied as first-pass estimates are found to be insufficient for predicting observed tidal water-table over-height in the Pioneer Valley, due to the sediment heterogeneities, non-uniform beach slopes and large tidal ranges of the system. The study reveals the spatial and temporal variability in tidally influenced hydraulic heads at the estuarine and coastal boundaries of the aquifer, and provides estimates of tidal water-table over-height up to 2.41 m during spring tides. These findings highlight the complexity of coastal groundwater systems, and the need to incorporate appropriate nearshore and near-estuary boundary conditions in models of regional groundwater flow in coastal aquifers.     

Morphology and sedimentary architecture of a beach‐ridge system (Anholt,the Kattegat sea): a record of punctuated coastal progradation and sea‐level change over the past ∼1000 years

Flakket on the island of Anholt in Denmark is a cuspate foreland facing the microtidal Kattegat sea. It is composed of a number of beach ridges typically covered by dune sand and separated by swales and wetlands. OSL dating indicates that the evolution of Flakket began c. AD 1000. Foreland growth was punctuated by a major episode of coastal reorganization leading to coastal retreat c. AD 1800. Coastal retreat led to the formation of an erosion surface that separates older and higher‐lying beach‐ridge and swale deposits from younger and lower‐lying deposits. The palaeo‐sea level is deduced from the architecture of the deposits, and interpretation of ground‐penetrating radar data and geomophological observations indicates that relative sea level was about 1.90±0.25 m above present sea level c. AD 1000, but about 0.00±0.25 m relative to present sea level c. AD 1830 and c. AD 1870. Anholt is situated at the margin of the uplifted Fennoscandian area; assuming uplift to be about 1.2 mm a^?1 it follows that absolute sea level was about +0.70±0.25 m at AD 1000, but around ?0.22±0.25 m at AD 1830 and around ?0.17±0.25 m at AD 1870. Within the uncertainties of the age control, the sea‐level indicators mapped by ground‐penetrating radar reflections and the variability of estimates of uplift found in the literature, the result obtained for AD 1000 is consistent with findings from the Stockholm area in Sweden and with a recently published global sea‐level curve.     

Water budget management of a coastal pine forest in a Mediterranean catchment (Marina Romea, Ravenna, Italy)

In Mediterranean coastal catchments, water management for preservation of pine forests and other natural areas faces particular challenges. Limited rainfall, water consumption by vegetation as well as subsidence, drainage and salt water intrusion all play an important role. Traditionally forest and water management are carried out independent of one another and do not consider water budget calculations. We show with this study that is very important to have quantitative information of all the components of the water budget as well as the size of the fresh water lenses in the aquifer to be able to integrate the water- and forest management. We use an integrated hydrologic-ecologic methodology based on easily attainable data to assess the monthly water budget of a coastal catchment, Marina Romea (Ravenna, Italy). We present detailed monthly water table records, rainfall data, drainage data, tree density and tree perimeter and use published sap flow measurements of single pine trees (Pinus Pinea) to quantify the actual transpiration of single pine trees in different periods of the year. Transpiration amounts to 10–30 l per day per tree. These values are confirmed by independent estimates of tree transpiration based on our water budget calculations: 9–34 l/tree/day. Because typically there are so many trees in planted pine forests, the total transpiration rates over the whole watershed take up a large percentage (up to 200 %) of the precipitation. In Marina Romea, four monitoring periods out of twelve, the tree transpiration is larger than precipitation. In nine monitoring periods, drainage in the watershed is larger than precipitation or tree water transpiration. The measurements and calculations show that not much freshwater is left to recharge the fresh water lens underneath Marina Romea. Monthly monitoring of groundwater table elevation and salinity in the pine forest of Marina Romea from March 2007 to February 2008 shows that the groundwater table strongly fluctuates and groundwater salinity is constantly very high (up to 17.7 g/l). Analytical calculations based on the Ghyben Herzberg Dupuit principle suggest that even a small continuous annual recharge of 15 mm could form a 2-m deep freshwater lens in the unconfined aquifer. This freshwater lens is not present in the study area and this is due to the fact that tree water transpiration and drainage take out most of the fresh water coming into the watershed. In catchments like Marina Romea, water consumption by the (natural) vegetation and seasonal differences as well as the fact that fresh water lenses are limited in salty surroundings should be taken into account in water and forest management.     

Environmental isotopic and hydrochemical study of water in the karst aquifer and submarine springs of the Syrian coast

The groundwater of major karst systems and submarine springs in the coastal limestone aquifer of Syria has been investigated using chemical and isotopic techniques. The δ¹⁸O values of groundwater range from ?6.8 to ?5.05‰, while those for submarine springs vary from ?6.34 to +1.08‰ (eastern Mediterranean seawater samples have a mean of +1.7‰). Groundwater originates from the direct infiltration of atmospheric water. Stable isotopes show that the elevation of the recharge zones feeding the Banyas area (400–600 m a.s.l.) is higher than that feeding the Amrit area (100–300 m a.s.l.). The ¹⁸O_extracted (¹⁸O content of the seawater contribution) for the major submarine springs suggests a mean recharge area elevation of 600–700 m a.s.l., and lower than 400 m a.s.l. for the spring close to Amrit. Based on the measured velocity and the percentage of fresh water at the submarine springs outlet, the estimated discharge rate is 350 million m³/year. The tritium concentrations in groundwater (1.6–5.9 TU) are low and very close to the current rainfall values (2.9–5.6 TU). Adopting a model with exponential time distribution, the mean turnover time of groundwater in the Al-sen spring was evaluated to be 60 years. A value of about 3.7 billion m³ was obtained for the maximum groundwater reservoir size.     

Water table fluctuation analyses and associated empirical approach to predict spatial distribution of water table at Yeşilköy/AgiosAndronikos aquifer

The groundwater of the deep Ye?ilköy aquifer is the only water resource for agricultural and domestic consumption at the Karpaz Peninsula of Cyprus, which stretches approximately 100 km from the northeast of capital Nicosia to the northern tip of Cyprus. During the last decade, over-pumping and following dry periods have depleted the groundwater resources and the water surface elevation of the aquifer has dropped. The aim of this study is to understand the behavior of the Ye?ilköy aquifer in the last decade for the proper management of groundwater resources. This has been achieved based on well survey and field survey studies, monitoring programs followed by pumping tests, and safe yield analysis. Most of the research effort has been focused on field and well survey studies to quantify agricultural water consumption and abstraction rates from the aquifer. A long-term groundwater level monitoring program, short-term continuous groundwater monitoring and pumping tests provided information for the regression analyses while deriving a sixth order polynomial relationship between the period parameter and the head parameter. The equation was helpful to predict the short-term behavior of the water level when the present hydrogeological conditions prevail. The pumping test results satisfied the hydraulic properties of calcarenite formation yielding T = 1,782 m²/day and S = 0.0012. The results of safe yield analysis show that the annual deficit of the aquifer is 0.496 million cubic meters (MCM), which is equivalent to a 0.6 m drop in groundwater levels per year. Finally, the resultant annual safe yield of the aquifer is estimated as 0.84 MCM.     

Threatened archaeological,historic, and cultural resources of the Georgia Coast: Identification,prioritization and management using GIS technology

Archaeological sites in beach and estuarine environments are continually threatened by diverse natural marine processes. Shoreline erosion, bluff retreat, and sea level rise all present potential for site destruction. Using historic maps, aerial imagery, and field survey methods in a GIS, 21 potentially significant archaeological sites on Georgia barrier islands were selected for determination of site‐specific rates of shoreline change using a powerful, new, moving‐boundary GIS analysis tool. A prioritized list of sites, based on the order of site loss from erosion, was generated to assist coastal managers in identifying and documenting sites most at risk. From the original selection of 21 sites, 11 sites were eroding, 8 shorelines were stable, and 2 shorelines were accreting. The methodology outlined here produces critical information on archaeological site loss rates and provides a straightforward means of prioritizing sites for detailed documentation. © 2010 Wiley Periodicals, Inc.     

International viewpoint and news

The investigations were carried out in order to evaluate change of the beaches profile during the period 1993–2008 and to elucidate main trends of the coastal dynamics. Morphometric indicators (beach width, height and inclination) were measured every year during the period 1993–2008 in 70 measuring stations located along the coastline. It was determined that the dynamic shoreline of the mainland during 1993–2008 receded by 10.2 m and the dynamic shoreline of the Curonian Spit advanced into the sea by 8.3 m. The different morphometric beach indicators changed to varying extents over the period 1993–2008, but comparison of values for 1993 and 2008 showed that those changes were small. The average beach width increased by 1.2 m on the mainland coast and by 0.5 m on the Curonian Spit coast. The average beach height also increased negligibly: by 0.5 m on the mainland coast and by 0.1 m on the Curonian Spit coast. The average beach slope inclination increased by 0.012 (from 0.065 to 0.077) on the mainland coast and by 0.005 (from 0.073 to 0.078) on the Curonian Spit coast. The measurements show that, despite being the most dynamic elements in the coastal system, these beaches managed to retain their morphometric indicators almost unchanged during the period of observation.