Coastal Features Research Articles

Incorporation of coarse-grained dredged material into marsh and shoreline restoration projects in coastal New Jersey

Millions of cubic yards of sediment are dredged every year in coastal New Jersey for the operation and maintenance of an extensive marine transportation system stretching from the New Jersey Harbor south along the Atlantic Coast from Sandy Hook to Cape May and north up the Delaware River. Dredged material from these public and private projects has been managed using a variety of placement approaches and technologies, from open-water disposal to landfilling to construction materials. For the past several decades, the State of New Jersey has advocated for and implemented a policy of beneficial use of dredged material rather than its disposal. The New Jersey Department of Transportation’s Office of Maritime Resources (NJDOT/OMR) is the lead state agency for research and implementation of beneficial use statewide. NJDOT/ OMR is also responsible for the recovery of the 200-mile network of shallow-draft navigation channels along the Atlantic coast of New Jersey that was damaged by a series of severe coastal storms, most notably Superstorm Sandy in 2012. For the past decade, considerable effort has been made to develop methods that use clean dredged material from the Atlantic region to rebuild and improve coastal features such as marshes, dunes, and beaches, thereby retaining the sediment in the ecosystem. Although there have been a number of successful beneficial use projects, concerns remain about the long-term sustainability of the program due to high cost, timelines, scalability, habitat sensitivity, resiliency, aesthetics, and other factors. This paper explores some of these issues and proposes solutions. It focuses on the use of available coarse-grained material as a way to provide resiliency to these restored features while increasing scale and efficiency, protecting aesthetics, and providing increased habitat value.

Pacific Islands Countries Declare Permanent Maritime Baselines, Limits and Boundaries

Abstract The Pacific Island countries are in the front line of adverse impacts from sea level rise. For the last decade the South Pacific Forum Members have been seeking ways to preserve their entitlements to their maritime zones and resources in the event of inundation of coasts and coastal features as a result of sea level rise. The issue was explored by the International Law Association in its 2018 Report and is being considered by a Study Group of the International Law Commission. This 2021 Declaration by the 18 Members of the South Pacific Forum purporting to fix permanently their maritime entitlements represents a major development in State practice for the region.

Morphological evidences of eustatic events in the last 14,000 years in a far-field site, East-Southeast Brazilian continental shelf

The post-LGM transgression was marked by eustatic variability events, comprising periods of increased sea-level rise, triggered by meltwater pulses (MWP) on polar regions, preceded by periods of stillstand. Several studies highlight the influence of such events on the geomorphology of far-field continental margins worldwide by mapping drowned relict features. However, there is still a lack of information in the South Atlantic and a major discussion about the global distribution of MWP-1B. The present work aims to investigate morphological evidences in the east-southeast Brazilian continental shelf (Abrolhos and Espírito Santo shelf), by examining shelf morphology using regional bathymetric data and high-resolution seismic sections. The analytical strategy involved comparing depth signatures of interpreted relict features with a set of sea-level curves. The results suggested the predominance of depositional process in shoreline sectors under closer influence of fluvial discharges during the Younger Dryas (YD). During YD stillstand or low sea-level rise rates (~60 m deep), it was possible to recognize the occurrence of a lagoonal system with shallow water/shoreface features (sandbanks, sand ribbons, or other bedforms) associated with tidal channels in the Abrolhos Shelf Depression and erosive features such as coastal cliffs. In the Espírito Santo outer shelf, the YD coastal features were characterized by barrier island systems associated with incised valley mouths and possible fringing reefs, in a context of a marginal shallow marine environment. All these features tend to be preserved in the modern shelf morphology due to a fast increase in the accommodation space that defines the end of the YD due to the onset of MWP-1B. In general, morphological interpretation revealed that MWP-1B caused the overstepping or drowning of those coastal features. Erosive features, defining the YD period, were also identified far from the influence of fluvial input. In these areas, coastal erosive processes prevailed and are morphologically expressed as abrasion terraces developed since the YD onset ~70 m and features like a paleo-sea cliff. During MWP-1B, the presence of shallow water reefs in the Abrolhos shelf is hypothesized, experiencing backstepping until their complete submersion. Despite the lack of additional data on composition, age and 3D geometry of the features, the morphological approach proposed here strongly supports the concept that eustatic events, triggered mainly in the Northern Hemisphere, influenced the shelf geomorphology and sedimentary processes evolution in the South Atlantic, during the last deglaciation.

Biogeochemical and Hydrological Drivers of Heterogeneous Nutrient Exports From Subterranean Estuaries

Submarine groundwater discharge (SGD) to coastal zones contributes terrestrial freshwater and nutrients that may support harmful algal blooms (HABs). The magnitude of nutrient exports via SGD depends on volumes of fresh groundwater discharge, its chemical composition, and modifications by biogeochemical processing within subterranean estuaries. Thus, the ability to upscale SGD exports requires knowing the range of chemical composition of inland groundwater and how those compositions may be transformed as fresh and saltwater mix within subterranean estuaries. These processes may create heterogeneous magnitudes of solute exports, even at small spatial scales, and such heterogeneities have rarely been assessed for regional or global SGD nutrient export estimates. To evaluate heterogeneity in subterranean estuary processes and nutrient export, we collected seasonal pore water samples in 2015–2016 at three proximal (<20 km) subterranean estuary sites in Indian River Lagoon, FL. Sites have homogenous hydrogeological settings, but differ in land use and coastal features, and include a mangrove site, an urban site, and a site offshore of a natural wetland. All sites exhibit little variation through time in nutrient concentrations and modeled SGD rates. In contrast, each site exhibits significantly different nutrient concentrations of potential fresh groundwater sources, fresh groundwater discharge volumes, and nutrient transformations within subterranean estuaries. Groundwater specific discharge correlates with nutrient concentrations, suggesting that higher residence times in the subterranean estuary increase biogeochemical transformations that reduce anthropogenic nutrient loads but increase in situ nutrient sources derived from organic matter remineralization. The differences in transformations lead to SGD nutrient contributions that differ by orders of magnitude between sites and have N:P ratios that are greater than the Redfield ratio (15) for the mangrove (29) and urban sites (28), but less than the Redfield ratio for the wetland site (8). These results indicate that heterogeneity of both absolute and relative nutrient export via SGD complicates integration of nutrient fluxes across regional coastal zones and evaluations of its impacts to coastal ecosystems. A better understanding of the drivers of heterogeneity, including subterranean estuary processes, land use, coastal topography, and vegetation dynamics could improve assessments of regional nutrient loading and upscaling for estimates of global solute cycles.

Postglacial sea-level lowstand on Cumberland Peninsula, Baffin Island, Nunavut

This study investigates the postglacial sea-level history of eastern Cumberland Peninsula, a region of Baffin Island, Nunavut, where submerged terraces were documented in the 1970s. The elevation gradient of emerged postglacial marine-limit deltas and fiord-head moraines led Arthur Dyke to propose a conceptual model for continuous postglacial submergence of the eastern peninsula. Multibeam mapping over the past decade has revealed eight unequivocal submerged deltas at 19–45 m below present sea level (b.s.l.) and other relict shore-zone landforms (boulder barricade, spits, and sill platform) at 16–51 m b.s.l. Over a distance of 115 km from Qikiqtarjuaq to Cape Dyer, the submerged coastal features increase in depth toward the east, with a slope (0.36 m/km) less than that of the marine-limit shoreline previously documented (0.58–0.62 m/km). The submerged ice-proximal deltas, deglacial ice limits, and radiocarbon ages constrain the postglacial lowstand between 9.9 and 1.4 ka cal BP. The glacial-isostatic model ICE-7G_NA (VM7) computes a lowstand relative sea level at 8.0 ka, the depth of which increases eastward at 0.28 m/km. The difference between observed and model-derived lowstand depths ranges from 1 m in the west to 10 m in the east and the predicted tilt is significantly less than observed (p = 0.0008). The model results, emerging data on Holocene glacial readvances on eastern Baffin Island, and evidence for proglacial delta formation point to a Cockburn (9.5–8.2 ka) age for the lowstand, most likely later in this range. This study confirms the 1970s conceptual model of postglacial submergence in outer Cumberland Peninsula and provides field evidence for further refinement of glacial-isostatic adjustment models.

Coastline Modeling Using Stacked Curve Spline Tension Interpolation

The coastal area is a dynamic environment influenced by atmosphere, land, and ocean interactions. Similarly, the position of coastlines is also changing due to natural and human-induced components, for instance, erosion, wave, daily tide, storm, and coastal development. In literature, coastline position can be identified based on proxies such as coastal features identified from an aerial photo or very high-resolution image and tidal datum-based indicators extracting from a ground survey. This research proposed a method in deriving datum-based coastline by integrating various bathymetric data, including single beam and multibeam echo sounding data, the National Digital Elevation Model, the national bathymetry data, as well as satellite-derived bathymetry data. The stacked curve spline tension method was applied to assimilate those various bathymetric data, and finally, the coastline was generated. Based on the accuracy assessment conducted, coastline similarity accuracy varies; namely, the LAT coastline had an accuracy of 29.28%, the MSL coastline was 65.45%, and the HAT coastline was 47.48%. These variations are due to several reasons, including the lack of input data, the density of depth data that varies greatly, the difference in data acquisition time between the data used for the LPI map and the data used in this study. Although the accuracy values obtained were not sufficiently high, the proposed method was quite promising to adopt. The method can be used as an alternative for the coastline model and overcome data, time, and cost limitations in providing national coastlines

Geomorphology of the seafloor north east of the Maltese Islands, Central Mediterranean

ABSTRACT This paper presents a geomorphological map of the seafloor north east of the Maltese Islands (Central Mediterranean) at a scale of 1:50,000. The map was compiled following the integration, analysis and interpretation of several high-resolution seafloor bathymetry datasets. Several structural features, coastal and marine landforms and anthropogenic features have been mapped. Most of the mapped submerged landforms – including fluvial, gravity-induced and karst landforms – appear to have been formed during the sea-level lowstand of the last glacial cycle. The map provides valuable insights on the submerged landscape of the Maltese Islands and its evolution since the Last Glacial Maximum.

Assessing the coastal sensitivity to oil spills from the perspective of ecosystem services: A case study for Canada's pacific coast

Coastal environment is one of the most important ecological and socioeconomic areas. However, increasing energy demand and economic development lead to a continuous gas and oil exploration, production, and traffics, which notably raise the risk of oil spill accidents in coastal areas. Sensitivity assessment aiming to determine the coastal features that would be severely impaired by spill incidents is a crucial part of the response planning. In this study, an innovative framework for coastal sensitivity mapping that incorporated ecosystem service (ES) valuation and multidimensional assessment was proposed. Sensitivity was computed by valuing physical, biological, and social-economical indicators from ES perspective and separating each indicator into specific coastal domains. For different ES typologies, provisioning services contributed most to the overall ES value followed by culture services, supporting services, and regulating services. For ES value in different coastal domains, the highest value was recorded in the water column followed by water surface, shoreline, and seabed. However, the shoreline ranked highest regarding the ES value per ha. Sensitivity assessment revealed that sensitive areas differed in different domains, both in distribution and extent. Compared with the scoring method, the ES valuation method showed more coincidence with Ecologically and Biologically Significant Areas (EBSA), representing a more precise and practical approach for sensitivity assessment. A three-dimensional (3D) oil spill model was also applied to generate maps of oil contamination probability in shoreline, water surface, and water column. The obtained results highlighted the significance of incorporating different coastal domains into oil spill responses, and the urgent demand to broaden and deepen our understanding of ecological processes across the vertical coastal zones.

Coastal morphology and heavy mineral accumulation in an upper-macrotidal environment – A geological-mineralogical approach from source to trap site in a natural placer laboratory (Channel Islands, Great Britain)

The Isles of Jersey and Guernsey, GB, are situated in the Bight of St. Malo which ranks among the upper-macrotidal environments with one of the highest tidal ranges ever measured on the globe. They are built up of metasedimentary and –magmatic basement rocks followed by a suite of gabbro-diorite-granite intrusive rocks. Based on sedimentological, geomorphological and mineralogical investigations focused on heavy minerals (HM) the coastal environment has been subdivided into three principal coastal types headland-, headland-bay and bay types. Chemical and physical weathering, neotectonics, eustatic sea level changes, wave action, land-derived sediment supply and aeolian processes had not only a strong impact on the various coastal landform series (CLFS) established but also on the variegated HM assemblages casting them into the role of markers for the coastal environment and some kind of an ore guide for marine placer deposits. Tidal-dominated coastal environments under study sculptured exclusively out of crystalline bedrocks are conservative with regard to the economic geology and potential of HM placer-type deposits provided while physical weathering predominates over the chemical one. The tidal processes in context with the other land-forming processes are special importance for the diversity of coastal features within the environment hosting HM on a small- and large-scale. Neotectonics may accentuated or suppress tidally-controlled features in that strong uplift and provokes typical tidal features to get suppressed so that vast tidal flats are missing in a great deal of coastal areas and rocky coasts formed instead with consequences for the accumulation of HM. The “GMS tool (granulometry-morphology-situmetry) has methodologically proved to be very effective for the study of the coastal zones hosting HM in two principal ways. Granulometric and the morphological variation of HM can successfully be used for the host rock environment analysis (“ore guide”). Morphometric studies and situmetric measurements of gravel clasts in the coastal sediments bearing HM accompanied by similar measurement of joints and faults cutting through the bedrock can assist in the localization of HM trap sites in shoreline platforms and their rock veneer. The HM associations in upper-macrotidal environments are variegated in terms of morphology, mineralogical composition and their geomorphological trap sites so that they constitute a natural laboratory for environment analysis in terms of hydrodynamic and (paleo) climate along marine terrigenous shorelines and help better understand the way of HM from source to trap site in modern and paleoplacers.

Estratigrafía, paleoambientes y correlación del Paleozoico Superior en la localidad Río Francia, Cuenca Paganzo, Argentina

The Tupe and Patquía formations are known for their marine, deltaic, river, and eolian deposits that record different Late Paleozoic events in the Paganzo Basin. However, in the area of the Río Francia (Province of San Juan, Argentina), these units are relevant because they are located in a strategic place of connection with the southernmost sedimentary sequences in the Paganzo Basin on the Central Precordillera. The Tupe Formation (which by palynological data would represent the late Serpukhovian-Gzhelian interval) has a minimum thickness of 140 m of bioturbed mudstones with a minor percentage of coarse to fine sandstones intercalated. In this work they are grouped into 3 facies associations: I lagoon; II barrier island and III shoreface. The Patquía Formation (from palynological data, in this locality, of Cisuralian in age), it is a typical succession of red beds with deposits of fine -grained sandstones with cross-bedding, and alternation of sandstones with mudstones. 3 facies associations were differentiated: IV anastomosed fluvial; V eolian and VI playa lake. A correlation analysis between these formations and their lithostratigraphic equivalents provided possible scenarios for the western sector of the Paganzo Basin, showing a lineament of units with coastal environment features for the Tupe Formation and equivalents at these latitudes. On the other hand, the Patquía Formation and their equivalents display a progressive continentalization from north to south.

Semi-Supervised Segmentation for Coastal Monitoring Seagrass Using RPA Imagery

Intertidal seagrass plays a vital role in estimating the overall health and dynamics of coastal environments due to its interaction with tidal changes. However, most seagrass habitats around the globe have been in steady decline due to human impacts, disturbing the already delicate balance in the environmental conditions that sustain seagrass. Miniaturization of multi-spectral sensors has facilitated very high resolution mapping of seagrass meadows, which significantly improves the potential for ecologists to monitor changes. In this study, two analytical approaches used for classifying intertidal seagrass habitats are compared—Object-based Image Analysis (OBIA) and Fully Convolutional Neural Networks (FCNNs). Both methods produce pixel-wise classifications in order to create segmented maps. FCNNs are an emerging set of algorithms within Deep Learning. Conversely, OBIA has been a prominent solution within this field, with many studies leveraging in-situ data and multiresolution segmentation to create habitat maps. This work demonstrates the utility of FCNNs in a semi-supervised setting to map seagrass and other coastal features from an optical drone survey conducted at Budle Bay, Northumberland, England. Semi-supervision is also an emerging field within Deep Learning that has practical benefits of achieving state of the art results using only subsets of labelled data. This is especially beneficial for remote sensing applications where in-situ data is an expensive commodity. For our results, we show that FCNNs have comparable performance with the standard OBIA method used by ecologists.

Last interglacial sea levels within the Gulf of Mexico and northwestern Caribbean Sea

Abstract. During the last interglacial (LIG) the volume of additional water in the world's oceans was large enough to raise global sea levels about 6–9 m higher than present levels. However, LIG sea levels vary regionally and those regional differences hold clues about the past distribution of ice sheets and local rates of subsidence and tectonic uplift. In this study, I used a standardized database template to review and summarize the existing constraints on LIG sea levels across the northern Gulf of Mexico and Caribbean shoreline of the Yucatán Peninsula. In total, I extracted 32 sea-level indicators including the insertion of 16 U-series ages on corals, 1 electron spin resonance age, 2 amino acid racemization ages, and 26 luminescence ages. Most dated sea-level indicators for the northern Gulf of Mexico are based on optically stimulated luminescence (OSL) ages of beach deposits of a mappable LIG shoreline. This shoreline extends from the Florida Panhandle through south Texas but is buried or removed by the Mississippi River across most of Louisiana. A similar feature is observed in satellite images south of the Rio Grande within the Mexican portions of the Gulf of Mexico but has yet to be dated. Elevations measured on portions of this feature close to the modern coast point to sea levels less than 1 m to ∼5 m higher than present for much of the northern Gulf of Mexico. However, a few, albeit undated, portions of the same shoreline located at more inland locations point to sea levels up to +7.2 m, attesting to up to 7 m of differential subsidence between the inland and coastal sites. Across the Yucatán Peninsula, U-series dating of corals has provided the main index points for LIG sea levels. Other carbonate coastal features such as beach ridges and eolianites have also been described but rely on corals for their dating. The maximum elevation of the LIG coral-based relative sea-level (RSL) estimates decrease from around +6 m across the Caribbean shoreline of the Yucatán Peninsula near Cancún, Mexico, to as low as −6 m to the south beneath the southern atolls of Belize, although discussion continues as to the validity of the ages for these southern corals. If these lower-elevation corals are LIG in age, their below-present elevations may be a result of vertical motion along faults dipping into the Cayman Trough. South of Belize only one purported LIG coral has been dated on the Isla de Roatán off the coast of Honduras at a likely tectonically uplifted elevation of 37.2 m. Thus the elevation of LIG sea levels within the inland siliciclastic shorelines of Guatemala and Honduras as well as the southwestern Gulf of Mexico remains poorly constrained and a potential venue for future research. The database described in this paper is available open access in spreadsheet format as Simms (2020), at this link: https://doi.org/10.5281/zenodo.4556163.

A Spatiotemporal Change Detection Analysis of Coastline Data in Qingdao, East China

This study focuses on the coastal features, environments, and dynamics to accurately describe and regularly monitor the Qingdao shoreline in eastern China. It collects categorical ETM+ and OLI data from 2000, 2010, and 2019 on the mainland coastline and explores the characteristics and spatiotemporal differences across the past 19 years by using remote sensing and geographic information system (GIS) technologies. The results show that the length of the Qingdao coastline has increased continuously over the last two decades, for a total increase of 18.14 km. There are different natural and artificial coastlines that have undergone major changes. The human-induced deterioration of coastlines has gradually and substantially risen from 53.63% in 2000 to 68.40% in 2019, while the length of the natural coastlines has decreased dramatically. Jiaozhou Bay focuses on areas with significantly changing coastlines, and major changes have occurred in the west and east of the Qingdao coast. The coastline has largely expanded seaward because of the comprehensive impact of natural and anthropogenic factors. The leading factor in coastal evolution is coastal engineering constructions. In addition, the top three other construction activities are the restoration of the aquaculture pond, salt field, and harbor edifices. The driving force that triggered the shift in the coastline reveals significant temporal heterogeneity.

Influence of manmade effects on geomorphology, bathymetry and coastal dynamics in a monsoon-affected river outlet in Southwest coast of Sri Lanka

A complex coastal environment with a river outlet, a sand spit barrier and an estuary of such coastal features is controlled by wave-induced hydrodynamics and sediment dynamics. The coastal dynamics patterns can be changed by natural or anthropogenic activities. This study is mainly focused on understanding the significant changes of geomorphology, bathymetry, and the coastal dynamics originated due to human influences in a monsoon-affected Kalu Ganga (River) outlet in Sri Lanka. In this research project, bathymetric variations before and after the collapse of sand spit barrier were analysed to understand the extent of the erosional and depositional effects. High-resolution satellite images in Google Earth Pro were also used to qualitatively analyse beach boundary changes before the collapse of the sand spit barrier. Temporal and spatial changes of beach boundary positions after collapse of the sand spit barrier were measured using high precision GPS surveying in river outlet including the evolving sand spit barrier. Nested wave model (Delft3D modelling suite) was applied to understand the wave climate changes. The data obtained from all methods were analysed to understand the geomorphological, bathymetric and coastal dynamic changes of the study area. The results show significant and widespread deepening of bathymetry up to 1–2 m extending as far as 2 km offshore from the river outlet initiated after the collapse of the sand spit barrier. Further, the study shows separation from the mainland and buckling of the sand barrier was initiated by anthropogenic activity coupled with the release of riverine floodwater and strong waves during southwest monsoon season. The weakened and buckled sand spit barrier was migrated and welded to the mainland during calm weather of northeast monsoon. This has resulted complete change of coastal dynamics in the Kalu Ganga (River) outlet area. Since the sediment dynamics and hydrodynamics completely changed, even after 2 years, the sand spit barrier across the river outlet has not been recreated naturally. Therefore, important structures in Kalutara coastal area were threatened due to severe erosion. This study shows understanding such coastal morpho-dynamic and hydrodynamic changes are vital to implement proper coastal prevention management strategies.

Evaluation of various image transformation techniques for the delineation of coastal sand dune features in Tamil Nadu, South India

Image transformation techniques such as Principal Component Analysis, Minimum Noise Fraction and Independent Component Analysis were used for extracting information from the satellite image in various fields, but its application in landform mapping seems to be very less. The objective of the study is to demonstrate the viability of less explored image transformation techniques for delineating coastal dune complex and associated features using European satellite Sentinel 2 multispectral data. Based on the difference in lithology and vegetation cover the study sites has been chosen to extract coastal dune complex features such as dune ridges, dune with or without vegetation, swale with or without vegetation and water. Overall results of ICA shows enhanced visualization followed by PCA in bringing up the fine variations, identifying micro landforms within the dune complex from the optimum band combinations. Thus, sentinel data coupled with advanced image processing technique like ICA could identify maximum information about the boundaries and micro landform within the coastal sand dune complex in a cost-effective manner. However, in areas with dense vegetation cover none of these techniques has given good results in identifying the boundary or in identifying the micro landforms.

Prediction of Land Use and Land Cover Changes in Mumbai City, India, Using Remote Sensing Data and a Multilayer Perceptron Neural Network-Based Markov Chain Model

In this study, prediction of the future land use land cover (LULC) changes over Mumbai and its surrounding region, India, was conducted to have reference information in urban development. To obtain the historical dynamics of the LULC, a supervised classification algorithm was applied to the Landsat images of 1992, 2002, and 2011. Based on spatial drivers and LULC of 1992 and 2002, the multiple perceptron neural network (MLPNN)-based Markov chain model (MCM) was applied to simulate the LULC in 2011, which was further validated using kappa statistics. Thereafter, by using 2002 and 2011 LULC, MLPNN-MCM was applied to predict the LULC in 2050. This study predicted the prompt urban growth over the suburban regions of Mumbai, which shows, by 2050, the Urban class will occupy 46.87% (1328.77 km2) of the entire study area. As compared to the LULC in 2011, the Urban and Forest areas in 2050 will increase by 14.31% and 2.05%, respectively, while the area under the Agriculture/Sparsely Vegetated and Barren land will decline by 16.87%. The class of water and the coastal feature will experience minute fluctuations (<1%) in the future. The predicted LULC for 2050 can be used as a thematic map in various climatic, environmental, and urban planning models to achieve the aims of sustainable development over the region.

19세기 이후 러시아의 한반도 주변 조사에 관한 연구: ｢國譯 韓國誌｣를 중심으로

One of the areas of interest that Russian Empire had in Korea was its value as a stable source of food especially beef, as seen in Garin’s travel journal and KOPEИ. Russia named about 200 marine and coastal features of the East Sea via exploration. Most of place names have disappeared, but some remain as marine names near Primorsky state, so toponym users can find those names such as Bukhta Reid Pallada and Zaliv Posiet (Posiet Bay) through Google Earth service. The survey of inland areas seemed to be as an important part as the survey of coastal areas. It is believed that the KOPEИ expresses the direction of the Russian government's interest in Korea. Besides the contents of history, language, administration, and political systems, the contents of the KOPEИ will be sufficiently important enough for geographical research on Korean physical geography, Korea territory, as well as economy and trade until the 19th century.

Distribution and cementation characteristics of beachrocks along southern, southwestern and western coast of Sri Lanka

Beachrocks are sedimentary structures where gravelly or sandy beaches have been transformed into rock outcrops formed through precipitation of connective cements amid their interstices. They are well-noted coastal features along the coastal belt of Sri Lanka due to the prevalent tropical climate. This study was aimed at gathering data on surface nature and cementation characteristics of beachrock occurrences along a part of Sri Lankan shoreline through field observations and a series of analyses including X-ray diffraction, X-ray fluorescence, scanning electron microscopy (SEM) techniques and petrographic thin-section analysis. The combined research findings from different techniques are also employed as a preliminary step to determine the formation mechanism of the studied beachrocks. The seaward-inclined low-angle beds running parallel to present shoreline are composed mostly of sandstone with occasional conglomerate. Almost all the beachrocks are made of quartz grains amalgamated by cement. One remarkable feature of Sri Lankan beachrocks is the presence of heavy minerals generally in thin lamina form. The cementing agents are predominantly composed of metastable carbonate phases, high magnesium calcite (HMC) and aragonite (Ar) with varying microfabrics and textures. From SEM examinations and thin-section images, main morphologies identified are acicular Ar, scalenohedral magnesium calcites along with bridge cements and micritic coatings which are typical of a marine-phreatic precipitation with the exception of occasional meniscus cements. Further, the presence of evidences of living organisms may be an indication of influence from the biological aspects which can be confirmed by more detailed analyses.

Bringing Bathymetry LiDAR to Coastal Zone Assessment: A Case Study in the Southern Baltic

One of the major tasks in environmental protection is monitoring the coast for negative impacts due to climate change and anthropopressure. Remote sensing techniques are often used in studies of impact assessment. Topographic and bathymetric procedures are treated as separate measurement methods, while methods that combine coastal zone analysis with underwater impacts are rarely used in geotechnical analyses. This study presents an assessment of the bathymetry airborne system used for coastal monitoring, taking into account environmental conditions and providing a comparison with other monitoring methods. The tests were carried out on a section of the Baltic Sea where, despite successful monitoring, coastal degradation continues. This technology is able to determine the threat of coastal cliff erosion (based on the geotechnical analyses). Shallow depths have been reported to be a challenge for bathymetric Light Detection and Ranging (LiDAR), due to the difficulty in separating surface, water column and bottom reflections from each other. This challenge was overcome by describing the classification method used which was the CANUPO classification method as the most suitable for the point cloud processing. This study presents an innovative approach to identifying natural hazards, by combining analyses of coastal features with underwater factors. The main goal of this manuscript is to assess the suitability of using bathymetry scanning in the Baltic Sea to determine the factors causing coastal erosion. Furthermore, a geotechnical analysis was conducted, taking into account geometrical ground change underwater. This is the first study which uses a coastal monitoring approach, combining geotechnical computations with remote sensing data. This interdisciplinary scientific research can increase the awareness of the environmental processes.

GEOTECHNOLOGY APPLIED TO THE MORPHOLOGICAL ANALYSIS OF ARACATIMIRIM RIVER ESTUARY (TORRÕES - CE)

Abstract. Estuaries are unstable coastal environments of transitional character between the continent and the ocean that plays an important role in fauna reproduction. In general, these types of coastal features have suffered several environmental impacts due to inadequate forms of use and occupation, which result in significant modifications in the morphology of river mouths. This work aims to apply geotechnologies to study the morphological changes at the mouth of Aracatimirim River, Ceará, Brazil, contributing with useful information on the monitoring and environmental management of tropical coastal estuaries. The methodology was divided into three stages: recognition of the study area; field activity and data processing and integration. The Aracatimirim River estuary underwent major changes between 1985 and 2013, where it was possible to identify five evolutionary phases into this period. Previously, built by bar, it evolved to an estuary of coastal plain, accompanied by the progression of Torrões beach and agglutination of "barriers spits" to the continent. It is the main navigable river of the area of Itarema municipality. After the development of this work, it was possible to conclude that the forms of use and occupation in the surroundings of the Aracaratimirim River estuary had a wide growth in the last years, which reflects clearly in the estuary morphology, currently classified as an estuary of coastal plain. The morphological changes within the estuary interfere on not only the environmental conditions, but also in the economy and social conditions of the local community.