Search

Williams, H.F.L., 2024. Testing digital elevation model of difference (DoD) estimation of washover fan thickness, Matagorda Peninsula, Texas. Journal of Coastal Research, 40(5), 852–859. Charlotte (North Carolina), ISSN 0749-0208. Washover fans are a fundamental component of coastal sediment budgets. While fans can be relatively easily delineated on air photos to obtain fan area, measurement of fan thickness, which is required for volume estimation, is problematic. Field surveys can be conducted, but fieldwork can be labor-intensive, costly, and time-consuming and have access problems. This study used pre- and poststorm LIDAR digital elevation models (DEMs) to create a digital elevation model of difference (DoD), which was then used to estimate the mean thicknesses of 10 Hurricane Harvey washover fans on Matagorda Peninsula, Texas. The accuracy of the LIDAR-derived fan thicknesses was assessed by comparing the LIDAR results to fan mean thicknesses based on pits excavated into fans. Seven out of 10 LIDAR-based thicknesses underestimated pit-based thicknesses, suggesting the presence of systematic bias in the LIDAR-derived DEMs. Underestimation of fan thicknesses was in the range of 36% to 56%. The source of the suspected bias is uncertain; it is possible that compaction of marsh sediments by the washover fans lowered the fans and reduced their apparent thicknesses. It is concluded that pre- and post-storm LIDAR DEMs can be used to estimate washover fan thickness, but in areas of compactible substrates, such as coastal marshes, steps should be taken to identify, evaluate, and address potential bias in the DEM data. [ABSTRACT FROM AUTHOR]

Yu, J.J.; Kim, D.W.; Lee, E.J., and Son, S.W., 2022. Mid- and short-term monitoring of sea cliff erosion based on structure-from-motion (SfM) photogrammetry: Application of two differing camera systems for 3D point cloud construction. Journal of Coastal Research, 38(5), 1021–1036. Coconut Creek (Florida), ISSN 0749-0208. Sea-level rise due to climate change is influencing coastal areas globally, which represent an important food and recreational resource for humanity. Accordingly, coastal monitoring is of vital importance. Recently, coastal erosion monitoring has been performed using various methods related to structure-from-motion (SfM) photogrammetry. In coastal topography, sea cliffs can have high elevations and uneven surfaces, making them challenging to model using SfM photogrammetry when capturing images using a single device from one direction owing to occluded areas during the construction of a three-dimensional point cloud (3D PCD). Therefore, in this study, two types of cameras were used to construct an appropriate 3D PCD of sea cliffs. Sea cliffs were photographed by an unmanned aerial vehicle (UAV) and by terrestrial cameras, and the resulting 3D PCD was constructed using fusion and integration methods during image processing. Sea cliff monitoring was performed separately for mid- (9 mo) and short-term (pre- and posttyphoon) periods, during which geomorphological changes could be monitored using the multiscale model-to-model cloud comparison (M3C2) technique. The proposed method effectively reduced the occluded area while sufficiently detecting geomorphological changes in the sea cliffs. [ABSTRACT FROM AUTHOR]

Greipsson, S., 2022. Spatiotemporal patterns of Leymus arenarius nebkhas during early primary succession on the subArctic coastal sand plains of Iceland. Journal of Coastal Research, 38(2), 269–278. Coconut Creek (Florida), ISSN 0749-0208. A spatiotemporal analysis of phytogenic mounds (nebkhas) of the pioneer dune building grass Leymus arenarius was assessed during primary succession on three coastal sand plains in Iceland. Extensive sand plains were formed on the study sites due to catastrophic glacial river floods associated with sub-glacial volcanic activities. Present and past spatial patterns of Leymus-nebkhas were examined by the use of satellite images and high resolution aerial photographs and confirmation through field work. The colonization patterns of the nebkhas were studied from the initial phases and up to a maximum period of 54 years on the sand plains Skeidararsandur, Myrdalssandur, and Skogarsandur. The hypothesis was that nebkhas would be clustered and nonrandom in early phases of the primary succession but would have random configurations at later stages. Average density of nebkhas was low within 10 years of colonization on Skeidararsandur (0.55–0.67 dunes ha–1) and the spatial configuration was found to be highly nonrandom (clumped). Following the initial colonization of L. arenarius, the increase of nebkha density with time followed a similar nonrandom pattern on Myrdalssandur with final average density of 6.12 nebkha ha–1. On Skogarsandur, the spatial configuration of nebkhas was random with final average density of 7.08 nebkha ha–1. Nonlinear cubic polynomial regression analysis showed a very strong relationship (R2 = 0.989) for the average density of nebkha for 60 years on Skogarsandur. On the coastal sand plains, the spatial configuration of nebkha was observed to progress with time from nonrandom towards random distribution. This study supports the view of deterministic spatiotemporal pattern of nebkhas during early primary succession on the coastal sand plains. The nebkha density was most likely a function of sand drift on the plains, significantly decreasing (R2 = 0.93) away from the sand source of the glacier river Jökulsa on Skogarsandur. The results are discussed in relation to ecological restoration. [ABSTRACT FROM AUTHOR]

González Rodríguez, S.V.; Valdecantos, V.N.; Diez, J.J.; del Campo, J.M., and Antón, M.M., 2021. Comparing the effects of erosion and accretion along the coast of Cartagena De Indias, Colombia. Journal of Coastal Research, 37(6), 1204–1223. Coconut Creek (Florida), ISSN 0749-0208. This research paper is a study of the transformation of the coastal landscape. It is based on the modification of the coastline as the symbolic and dynamic border between the continent and the ocean. The methodology is a comparison of two cartographic maps from different time periods. The first map is from the General Archive of the Colombian Nation published in 1822, and the second is the result of an assembled image based on aerial photographs obtained with Google Earth during 2018. The procedure is divided into three stages. In the first stage, the maps were georeferenced using QGis and then vectorized using the design software AutoCAD. In the second stage, a superimposition was made to identify the changes in the coastline. Finally, the differences in areas were calculated and quantified by grouping them as appropriate in accretion or erosion. The obtained results suggest that the erosion in Cartagena de Indias during the evaluated period is higher with respect to the area of accretion obtained. A discussion comparing these results with different studies previously performed was had. It was concluded that Cartagena de Indias lost land, where its majority corresponds to mangroves and coral reefs. [ABSTRACT FROM AUTHOR]

Swanson, R.L.; Giglio, K.W., and Chi, L., 2021. Restoring a degraded, sentinel New England salt marsh to mid-20th century conditions (Flax Pond, New York, U.S.A.). Journal of Coastal Research, 37(5), 993–1011. Coconut Creek (Florida), ISSN 0749-0208. Flax Pond, located between Crane Neck and Old Field Point on the north shore of Long Island, is designated as a Significant Coastal Fish and Wildlife Habitat by the U.S. Fish and Wildlife Service and as a Scenic Recreational Reserve by the New York State Department of Environmental Conservation. The pond's tidal prism has been reduced about 18% over the past half-century as its inlet has shoaled and its tidal range diminished 33%, 0.6 m, all in low water. Reduced flushing has led to loss of wetlands, reduced water quality, increased pond salinity, and nighttime summertime hypoxia with concomitant reduction in pH. Historic charts, topographic surveys, and vertical aerial photographs were used to study the evolution of the pond's inlet from Long Island Sound (LIS). Tide, tidal current, and water quality observations were made and/or historical measurements were acquired at these locations: the pond's inlet, a proposed seawater intake for the Flax Pond Marine Laboratory, and the U.S. Geological Survey (USGS) water quality station some 650 m into the pond. The flux of water through the inlet from LIS and the change in bed slope through the pond inlet were measured. USGS data within the pond were used to determine when hypoxic conditions are likely to occur: an increase in bottom-water salinity of 2.1 in 9 years and in the elevation of low water of 18 mm y–1 from 2008–14. The environmental benefits of reconfiguring the inlet to increase the tidal prism to that of the 1970s were explored. This would reduce the existing flushing time by more than 50%. The design of the cross-sectional shape for the inlet is based on this tidal prism and a compatible depth entering LIS; it should stabilize the inlet opening and improve much needed pond flushing. [ABSTRACT FROM AUTHOR]

Jaramillo, C.; Sánchez-García, E.; Jara, M.-S.; González, M., and Palomar-Vázquez, J.M., 2020. Subpixel satellite-derived shorelines as valuable data for equilibrium shoreline evolution models. Journal of Coastal Research, 36(6), 1215–1228. Coconut Creek (Florida), ISSN 0749-0208. The analysis and prediction of shoreline variability are two of the main challenges in coastal engineering. Evaluating coastal behaviour in a target area usually requires access to long data series of high-resolution shoreline positions. Therefore, coastal engineers must have access to different data sources, such as topographic-bathymetric field campaigns, digital orthophotos, aerial photographs, video-camera monitoring systems, and satellite imagery. This last data source is the only one that has the great advantage of covering large areas of the world and including regular coverage of most coasts during all climates and seasons. However, mid-resolution satellite images have been neglected because the resolution available to the public is too coarse to provide information on most coastal morphodynamic changes. The aim of this study was to explore the applicability of mid-resolution satellite imagery with a subpixel acquisition method for the calibration and validation of equilibrium shoreline evolution models. The models' performance was assessed by means of a comparative analysis between shoreline-position data sets obtained from video-camera systems and satellite imagery at two beaches on the Mediterranean coast of Spain. Almost 4 months of shoreline measurements were considered for validation purposes of the models at Nova Icaria Beach, and more than 1.5 years of shoreline measurements were analyzed at Cala Millor Beach. The results show that the general erosion-accretion trend is adequately represented by the models compared to the shoreline measurements at a qualitative and quantitative level. [ABSTRACT FROM AUTHOR]

O'Leary, M. and Gottardi, R., 2020. Relationship between growth faults, subsidence, and land loss: An example from Cameron Parish, Southwestern Louisiana, USA. Journal of Coastal Research, 36(4), 812–827. Coconut Creek (Florida), ISSN 0749-0208. This study investigates the relationship between faulting, subsidence, and land loss in coastal Louisiana. A methodology that integrates three-dimensional (3D) seismic data, well logs, high-resolution topographic mapping (LIDAR), and historical aerial photography is successfully developed to identify fault-related geomorphic changes in southwestern Louisiana's Chenier Plain. Analysis of a 3D seismic survey and well logs reveals the presence of 10 normal faults that form an east-west graben in the middle of the study area. Well logs were used to further constrain the geometry of the faults. Shallow water well logs were used to map the faults at shallow depth, below the resolution of the seismic survey. Fault traces were extrapolated to the surface by maintaining constant dip and projected on LIDAR data. Elevation profiles derived from the LIDAR were conducted across the different faults, and results show that a distinct difference between the upthrown and downthrown sides of the faults occurs. Historical aerial photographs were used to investigate any change in geomorphology from 1953 to 2017 within the study area. Results reveal the occurrence of water bodies on the immediate downthrown sides of suspected fault traces. These findings suggest that faulting influences and focuses areas where subsidence is happening and subsequent land loss may occur, and detailed understanding of active shallow faulting in coastal areas can be used to identify regions that are at risk of land loss. [ABSTRACT FROM AUTHOR]

Laporte-Fauret, Q.; Castelle, B.; Marieu, V.; Bujan, S.; Michalet, R., and Rosebery. D., 2020. Coastal dune morphology evolution combining Lidar and UAV surveys, Truc Vert beach 2011-2019. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 163–167. Coconut Creek (Florida), ISSN 0749-0208. In the context of climate change, coastal dunes, which provide significant ecosystem services, are one of the most vulnerable coastal environments. Moreover, the lack of high resolution and large spatial scale data limits our understanding of coastal dunes, which are subject to important morphological variations over a wide range of spatial and temporal scales. This study is focused on combining non-intrusive remote sensing methods including a series of historical aerial photographs, airborne Lidar and UAV surveys in order to better understand the coastal dune morphodynamic on a wide range of spatial and temporal scales. On the time scale of decades, aerial photos indicate a reasonably stable coastal dune position, with large anthropogenic reprofiling and vegetation planting resulting in a reasonably alongshore-uniform morphology. On shorter time scales, the combination of Lidar and UAV 4-km surveys between 2011 and 2019 shows a quasi-steady dune volume increase by approximately 64 m3/m, associated with a foredune crest growth and a landward migration reaching 1.1 m and 0.54 m in average, respectively. On the other hand, the dune foot shows a more complex dynamics, dominated by a large landward migration (shoreline erosion) of approximately 20 m during the outstanding winter of 2013/2014 followed by a slow seaward migration (recovery). This study provides new insight into coastal dune morphological changes driven by both Aeolian and marine processes from the time scale of storm to approximately a decade, highlighting the relevance of UAV surveys for such applications. [ABSTRACT FROM AUTHOR]

Muñoz-Reinoso, J.C.; Villafuerte Jordán, R; Tejada-Tejada, M., 2020. Analysis of spatio-temporal changes in the vegetation cover of the coastal landscape of Doñana. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 113-117. Coconut Creek (Florida), ISSN 0749-0208. The analysis of changes is an important component in the understanding of the ecology of complex landscapes. The aim of this work was to study the long-term changes in the vegetation of the sands of Doñana since 1970 until present, in order to know their causes and processes. Repeated detailed photointerpretation of historical aerial images (1970, 1984, 2002, 2016) was used to map the most extended vegetation types in the Doñana sands. All the series were referenced, photointerpreted and normalized, and then processed to describe the changes produced in landcover/use. Observed vegetation changes in the protected area responded to changes in regional landscape management, as well as to local interactions in plant communities, and management. Thus, groundwater abstraction for cropping and urban supply benefited the most xerophytic plant communities, while the building of a tourist site and of a spit in the Tinto-Odiel estuary seems to be responsible for the stabilization of the mobile dunes. The expansion of Phoenicean junipers shows a successional process while the encroachment of stone pines responds to an invasion process triggered by forestry works. [ABSTRACT FROM AUTHOR]

Nahirnick, N.K.; Costa, M.; Schroeder, S., and Sharma, T., 2020. Long-term eelgrass habitat change and associated human impacts on the west coast of Canada. Journal of Coastal Research, 36(1), 30–40. Coconut Creek (Florida), ISSN 0749-0208. Eelgrass (Zostera marina) forms a critical nearshore marine habitat in temperate coastal ecosystems. For three small estuaries in the Southern Gulf Islands of British Columbia, changes in eelgrass area coverage and shape index (over the period of 1932–2016) were assessed using historical aerial photographs and unoccupied aerial system (UAS) imagery. In addition, changes in eelgrass area and shape index were evaluated in relation to landscape-level coastal environmental indicators, namely shoreline activities and alterations and residential housing density. All three eelgrass meadows showed a deteriorating trend in eelgrass condition; on average, eelgrass area coverage decreased by 45.1%, while meadow complexity as indicated by the shape index increased by 66.3%. Shoreline activities (boats, docks, log booms, and armoring) and residential housing density increased markedly at all sites over the study period and were strongly correlated to eelgrass area coverage and shape index. Changes in these landscape-level indicators over this period corroborate the observed decline in eelgrass habitat condition, because they suggest an overall deterioration of coastal environmental health in the Salish Sea due to increased use of the coastal zone, as well as declines in water quality due to urbanization. [ABSTRACT FROM AUTHOR]

The behavior of the shelly beach ridge system forming a more or less continuous barrier lying along the southern coast of the hypertidal Mont-Saint-Michel bay (NW France) is examined using a set of various data including aerial photographs since 1947, sediment cores collected in back-barrier salt marshes, ground penetrating radar profiles, and differential digital elevation models (DEMs). The latter shows that since the middle of the 20th century, the tidal flats extending in front of the ridge system experience erosion and accretion that alternate spatially according to cross-shore corridors. The shelly ridges are better developed on line with the erosional bands. The reasons for this erosion/accretion compartment pattern are not totally elucidated. It probably results from the combined influence of shellfish farms, tidal channels and reef present on the tidal flats on wave and current dynamics. At the decadal to pluri-decadal scale, the shelly beach ridge system behavior as well as its internal organization can partly be related to the fluctuations of hydrodynamic conditions controlled by the 18.6 years nodal tidal cycle. Periods of intense landward migration alternate with periods of relative stability during the peak and the trough of the cycle respectively. This general scheme is complicated due to variations in storm wave dynamics. The most morphogenic events happen potentially during coinciding nodal cycle peaks and enhanced storminess. Such conditions actually occurred around 1995-2000, resulting in the most prominent washover fan deposit preserved within the back-barrier infilling successions. These sediment successions evidence as well that no beach ridge system older than the 19th century is preserved in front of the Medieval dike built during the 11th century on a relict beach ridge, and on which the present-day system is backed. We suggest that the enhanced storminess conditions of the Little Ice Age provoked the reworking of beach ridges formed between the 11th and 19th centuries. Changes in quantity and type of mollusk shells, related to the shellfish farming development during the 20th century are also thought to have had positive consequences on the barrier building and stability. [ABSTRACT FROM AUTHOR]

Mud supplied by the Amazon River forms large banks that migrate along the Amazon-Orinoco Guianas coast under the influence of waves and currents, separated by 'inter-bank' zones (phases). Bank-welding onto the coast creates new land, followed by rapid mangrove colonization, and westward deflection of the mouths of the smaller rivers. A fine example is Pointe Isère, a mud cape that deflected the mouth of the Mana River in French Guiana. During inter-bank phases, higher wave energy can result in rapid and massive shoreline erosion, except where sandy-shelly cheniers develop from winnowing of coarse-grained bedload from the surrounding muddy matrix. In order to contribute to a better understanding of the rates and scales of shoreline change on the French Guiana coast, we conducted a GIS analysis on Pointe Isère using a >60-year record of aerial photographs and satellite images. The results show significant and quasi-continuous erosion of this mud cape at the multi-decadal timescale. A phase of massive retreat of the shoreline (>1 km between 1955 and 1972), was followed by much slower erosion up to 2015, probably due to: (1) the alongshore passage of several mud banks, and (2) the formation of a sandy chenier through concentration, by waves, of contemporary sand of fluvial origin stored in the inner mud-dominated shoreface, and of sand derived from erosion of an old inland chenier exposed as a result of shoreline retreat. The new chenier has also been characterized by a westward-elongating spit. The progressive demise of Pointe Isère finally resulted, in 2001, in a breach that created a new direct outlet for the Mana River, and sealing of the former outlet through downdrift distal spit welding onshore. Over the study period (1955–2017), the demise of Pointe Isère has involved a loss of 41.8 km2, much of it mangrove wetlands. This corresponds to about 8% of the total area of mangroves in French Guiana in 2015. Since 2015, a new phase of large-scale muddy accretion has been associated with the on-going isolation of the active sandy chenier. This probably heralds a new cycle of mud-cape formation in the vicinity of the mouth of the Mana that will lead to a new westward diversion of this river. During the continuous erosion of Pointe Isère, the longshore passage of several mud banks did not mitigate or counter erosion. This has important implications regarding the unpredictability of shoreline change on the Amazon-Orinoco coast, and the need to go beyond the common vision of such change in terms of mudbank (shoreline accretion) and inter-bank (shoreline erosion) phases that cover timescales of the order of years to a decade. [ABSTRACT FROM AUTHOR]

This paper aims to highlight the evolution of the Pays de la Loire sandy coast. No global synthesis has been done on the evolution of this coast and its rates of change at various periods of time. Furthermore, to our knowledge, no synthetic research has been carried out using this methodology, which enables the release of surface statistics per unit of time. The shoreline's evolution has been measured over various periods since 1950: from 1950 to 2010, the intermediate periods being 1950-1970, 1970-1990, 1990-2010 and finally 1990-2000 and 2000-2010. These dates are among the only ones to allow complete air coverage by aerial photographs. The photographs are used to finely analyze changes in 60 to 10-year periods of time, in order to target non-linear rates of change. Our methodology is rigorously applied as follow: (1) we create of a database of exhaustive aerial photographs, (2) we define and digitize the shoreline, (3) we estimate the error margins, (4) we calculate a regular segmentation of the shoreline per surface unit (which are regularly spaced at 25m along the coast), (5) we intersect the shorelines and these spatial units to measure the surfaces between each shoreline inside each spatial unit. Various linear and surface statistics expressing erosion or accretion rates are then calculated for each of the 6652 spatial units. Global statistics are presented at the regional level. They are then presented in more detail at the level of the sedimentary cells, and finally at the level of the spatial units constituting the sedimentary cells. This approach permits us to present a global sedimentary balance at various scales through (i) the rates of evolution converted in linear meter (ii) and especially the emphasis of the evolution of surfaces between these shorelines. This leads us to estimate precisely the accreting, eroding and stable or insignificant sectors per period. It appears that the Pays de la Loire region has a sandy coast which is usually in sedimentary accretion even though some local sectors have been in chronic erosion over the last 60 years. [ABSTRACT FROM AUTHOR]

This paper examines the spatial and temporal variations of cliff retreat rates over multi-temporal data of the Normandy cliffs. Data are derived from historical maps and aerial photographs and from recent lasergrammetry and photogrammetry monitoring. The diachronic analysis of all these data gives retreat rates of -0.1 to -0.5 m/yr. in line with the international literature. The spatial variations of the cliff retreat rates, at the Normandy scale, can be explained by geological structure, especially at the cliff foot, but also by the influence of cliff collapses or anthropogenic obstacles that disrupt the longshore drift. Multi-temporal data shows that the evolution of the cliffs occurs on scales from 10 to 70 years according to the lithology. The high resolution and frequency monitoring also provide information about the factors responsible for triggering gravitational landslides (rockfalls, slides, debris falls). The study proposes a regional warning threshold for the cliff characterized by landslides, under the dominating influence of rainfall and groundwater level evolution. In this respect the monitoring is inconclusive for chalk and limestone cliffs, because the origin of evolutions is more multifactorial (combination of more continental and marine processes). [ABSTRACT FROM AUTHOR]

Lee, K. and Lee, W., 2023. Temperature accuracy analysis of land cover around urban rivers using thermal infrared sensor-mounted UAV. In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 215-219. Charlotte (North Carolina), ISSN 0749-0208. With rapid industrialization and urbanization, city centres experience a higher temperature than the surrounding suburbs, a phenomenon known as the Urban Heat Island (UHI). Efficient management of the permeable surface of a city is necessary to reduce UHI. Rivers are the representative permeable surfaces of a city and require steady management. However, monitoring around rivers requires a higher spatial resolution of satellite images and aerial photographs. For a Thermal Infrared (TIR) sensor, obtaining high-accuracy information is difficult in a small area because of the low spatial resolution. As an alternative, high-resolution data can be obtained using an Unmanned Aerial Vehicle (UAV) mounted with a TIR sensor. However, none of the studies have assessed the accuracy according to the angle and shooting height. Therefore, it is necessary to study the method of acquisition of data according to the shooting height and sensor angle around the river area using the TIR sensor. In this study, TIR images were acquired for two rivers using UAV-mounted TIR sensors to evaluate the accurate shooting height and TIR sensor angle. Land Surface Temperature (LST) data were obtained by generating orthophotos using the acquired TIR images. Therefore, the most accurate LST data was obtained at a shooting height of 50 m and a sensor angle of 80°. Based on our analysis, an 80° sensor angle and a low shooting height was recommended for acquiring ground LST, depending on the shooting situation. [ABSTRACT FROM AUTHOR]

Sherwood, C.R.; Warrick, J.A.; Hill, A.D.; Ritchie, A.C.; Andrews, B.D., and Plant, N.G., 2018. Rapid, remote assessment of Hurricane Matthew impacts using four-dimensional structure-from-motion photogrammetry. Timely assessment of coastal landforms and structures after storms is important for evaluating storm impacts, aiding emergency response and restoration, and initializing and assessing morphological models. Four-dimensional multiview photogrammetry, also known as structure from motion (4D SfM), provides a method for generating three-dimensional reconstructions of landscapes at two times (before and after events) using only photos and existing information for ground control points. Here, these techniques were applied using National Oceanic and Atmospheric Administration (NOAA)-obtained oblique aerial photos taken before (2015) and immediately after Hurricane Matthew (2016) to assess coastal changes near Matanzas, Florida. This work demonstrated that 3D digital elevation models can be constructed within 48 hours of postevent photo collection without on-site ground control measurements. One advantage of timely SfM elevation-change assessments is that they avoid confusion of storm impacts with changes that occur after the event but before LIDAR surveys can be performed. The accuracy and precision of the 4D SfM maps were assessed a posteriori using the first-available LIDAR data, which were collected more than a month after the hurricane, and 11 independent ground-truth survey points measured a week after the hurricane. Horizontal coordinates of the 4D SfM reconstruction were biased by an average of 0.79 m (0.83 m root-mean-square difference; RMSD) compared with the ground-truth points, but vertical elevations were more accurate. They were biased from the LIDAR by −0.09 to −0.25 m, with ∼0.20 m RMSD from both the LIDAR data and five ground-truth points with good vertical positioning and 0.25 m RMSD from LIDAR data along a 60-m stretch of pavement. This level of precision was sufficient to quantify geomorphological change that was often in excess of 1 m. The methodology is conducive for rapid assessment of changes along short stretches (tens of kilometers) of coast with modest resources and could be scaled up for larger regions. [ABSTRACT FROM AUTHOR]

Bitoun, R.E.; Collin, A.; James, D., and Pioch, S., 2018. Modelling Saltmarsh Spatial Evolution at High Resolution from 1948 to 2100. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 676–680. Coconut Creek (Florida), ISSN 0749-0208. Saltmarshes are boundary sea-land-air ecosystems which are globally threatened despite the plethora of ecosystem services they provide. Their evolution is spatially complex and multifactorial, influenced mostly by ecological and physical drivers such as tidal range, wave energy, hydrologic components and climatic conditions. Saltmarshes can respond positively to climate change due to their adaptiveness especially in areas provided with high tidal energy. While the conditions and determinants of marsh evolution are known locally, the spatial mapping of such processes across time is strongly expected. It is hereby proposed to study the interactions of the spatial evolution of Beaussais' Bay saltmarsh (France) from 1948 to 2013 by means of ocean-climate data. Time series of the saltmarsh spatial response, based on five high resolution aerial photographs, were explained by a multiple linear regression on continuous temperature, precipitation and mean sea level data. The model significantly explained the average horizontal accretion of the marsh platform by local warming and rising sea-level (Pearson's correlation coefficient r=0.63, RMSE=5.22). The increase in temperature explains best the model (R2=0.88), while sea-level and precipitation are secondary predictors (R2=0.16 and R2=0.11, respectively). The model enabled fine-resolution mapping to be predicted based on both IPCC ocean-climate scenarios and historical trends of the marsh surface up to 2100. The findings confirm the trends observed so far, enhancing the importance of saltmarsh conservation as a coastal protection. Spatial modelling of the marsh platform evolution constitutes therefore an intuitive framework and accessible communication tool for coastal planners. [ABSTRACT FROM AUTHOR]

Kombiadou, K.; Matias, A.; Carrasco, R.; Ferreira, Ó.; Costas, S., and Vieira, G., 2018. Towards Assessing the Resilience of Complex Coastal Systems: Examples from Ria Formosa (South Portugal). In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 646–650. Coconut Creek (Florida), ISSN 0749-0208. The present paper contributes to assessing the resilience of a complex barrier island environment, namely of the Ria Formosa multi-inlet system in southern Portugal. The long-term morphologic evolution of four study areas during the last 60 years (1947 to 2014) is analysed based on aerial photographs, including the environments of oceanic and backbarrier beaches, dunes and salt marshes. The results show that each study area responded to external drivers (inlet stabilisation works, storms, etc.) differently, evolving in distinct patterns during the study period. All four study areas appear resilient to external pressures and/or forcing conditions, since they are either transforming (Barreta and Culatra islands), or adapting (Cabanas island and Cacela peninsula) or remaining stable at a near-equilibrium state (Tavira island). Based on the analysis of the multi-decadal evolution of the sites, four resilient barrier states are identified, related to the maturity and growth of the barrier. In the next stages, the research will focus on the relation between medium to short-term changes, aiming at understanding the response and feedbacks of the environments to specific drivers of change and relating them to resilience indicators. [ABSTRACT FROM AUTHOR]

The Kandelia candel (L.) Druce mangrove forest in the Kuantu Nature Reserve, North Taiwan, has experienced rapid expansion since 1978. This study assesses the current extent and historical expansion of the mangroves by means of aerial photograph interpretation. An analysis of a time series of aerial photographs, covering the period from 1978 to 2012, has revealed major changes in the distribution of mangroves in relation to the geomorphic changes in the Kuantu Nature Reserve. The results indicate that the area-increasing rate was highest (2.27 ha/y) during the 1986-94 period, meaning the most rapid encroachment of mangroves into the habitats of Cyperus and Phragmites saltmarshes. Based on the Shannon diversity index t test, with the encroachment of Kandelia, the landscape composition in the Kuantu Nature Reserve has been dominated by the mangrove swamp of Kandelia. The geomorphic changes in the area of accretion and erosion were derived from the 0-m contour in the 1:5000 topographic maps in 1978, 1986, 1994, and 2005. Based on a review of related literature, the possible driving forces of geomorphic changes are explained by human impacts (e.g., land subsidence because of the overpumping of groundwater and collapse triggered by sand pumping) and natural forces (e.g., increased accretion induced by mangroves and headward expansion of tidal creek and typhoon-induced erosion). The complicated interplay between vegetation and landform in the Kuantu Nature Reserve is discussed from the viewpoint of biogeomorphic succession. Similar mangrove expansion cases are also examined. [ABSTRACT FROM AUTHOR]

Takamura, M.; Udo, K.; Sato, M., and Takahashi, K., 2016. Analysis of Coastal Erosion due to the 2011 Great East Japan Tsunami and Its Recovery Using Ground Penetrating Radar Data. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 477-481. Coconut Creek (Florida), ISSN 0749-0208. The 2011 Great East Japan Tsunami caused severe beach erosion along the Pacific coast. Eroded beaches began to recover rapidly after the tsunami, but the rate of beach recovery declined recently. We conducted a ground-penetrating radar (GPR) and borehole survey at Yamamoto Beach, which was eroded by the 2011 tsunami, to understand the tsunami recovery process using a new method that combines GPR, satellite images or aerial photographs, and tidal data. We compared reflective surfaces with geological layers observed using the GPR and borehole survey, respectively, to investigate the relationship between the recovery process data obtained from the proposed method and the actual underground structure. The result of the GPR survey at Yamamoto Beach suggests that the estimated profiles from April 4, 2011 to November 2012 maintain a gradient ranging 0.05-0.13 and that recovery speed decelerated with time after the tsunami. The sedimentary structure after November 2012 differs from the previous structure as a result of levee construction. Boundaries formed by a layer between the sand and the sand with gravel layers were observed and found to be nearly consistent with the GPR reflection planes. GPR results identified differences in the water content ratio between the layers owing to changes in grain size. Moreover, GPR reflections appear where layer boundaries are not observed. This also suggests that GPR is capable of recording differences in soil properties that cannot be identified visually. [ABSTRACT FROM AUTHOR]

Adnan, F.A.F.; Hamylton, S.M., and Woodroffe, C.D., 2016. A Comparison of Shoreline Changes Estimated Using the Base of Beach and Edge of Vegetation Line at North Keeling Island. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 967 - 971. Coconut Creek (Florida), ISSN 0749-0208. The vulnerability of reef islands is often assessed by measuring changes in shoreline positions over time. Historical aerial photographs provide valuable information of past shoreline dynamics and are commonly incorporated in shoreline change assessment. Edge of vegetation line is the most common shoreline proxy adopted for assessments of reef island change because it is a visually distinguishable feature in aerial photographs, when compared to other coastal features such as high water line and base of beach. This study assesses shoreline changes of North Keeling Island from aerial photographs taken in 1987 and 2011 to evaluate the implications of adopting edge of vegetation line (EVL) and base of beach (BB) as shoreline proxies. The Digital Shoreline Analysis System (DSAS) (ArcGIS 10.2) method was applied to calculate shoreline changes using both proxies. Results indicate that EVL and BB generated different rates of change and variations of shoreline behaviour were observed at different locations around the island. The EVL indicated that the surface area of the island reduced in size over the 24 years, while in contrast, BB indicated that the island had accreted. Findings of this study imply that reef island shorelines are dynamic features which vary spatially and an improved understanding of the processes that underlie shoreline behaviour requires a geographical spread of sites for shoreline proxies when assessing shoreline change. [ABSTRACT FROM AUTHOR]

Natural and anthropogenic controls contribute to coastal change at diverse temporal and spatial scales. This study presents an analysis of storminess and a correlation with the medium-term shoreline erosion rates in two sand spits of the Gulf of Cadiz (SW Spain). Recession rates were assessed by means of aerial photographs and orthophotographs considering the dune foot as an appropriate proxy. Storm events were obtained from a combination of coastal wave buoy data and the hindcast database of the HIPOCAS project. The characteristics of the storms were compared with shoreline changes determined using the aerial photographs, and the correlation between them was estimated and discussed. The best agreement between storms and shoreline change was observed in section 1 of Sancti Petri sand spit, while Valdelagrana sand spit showed a lower dependence between shoreline erosion and storminess. This is related to the contrasting exposure of both sites, with Sancti Petri being more exposed and thus more sensitive to storm impact. It is suggested that the main causes of retreat in Valdelagrana are human interventions performed on the coast and in the nearby rivers (breakwaters, jetties and dams). Nevertheless, storminess contributes to modulate recession rate, so that erosion rates increase when the number of storms is higher. [ABSTRACT FROM AUTHOR]

Suursaar, Ü., Alari, V., Tõnisson, H., 2014. Multi-scale analysis of wave conditions and coastal changes in the northeastern Baltic Sea. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 223-228, ISSN 0749-0208. Temporal variations of shoreline changes have been analyzed and interpreted in three differently exposed Estonian coastal sections. Using coastline contours that have been recorded frequently over the last twelve years, as well as recently digitized aerial photographs, orthophotos and old topographic maps (some of them dating back to 1900), all overlaid in the Mapinfo software, areal changes over different sub-periods were calculated. To explain the shoreline changes, two different wave modelling approaches were used and mutually compared. Both the BaltAn65+ reanalysis (an ERA-40 refinement) forced SWAN model hindcast (1965-2005) and the point model runs (1966-2012), locally and independently calibrated against extensive wave measurements in these coastal study sites, confirmed specifically higher (and increasing) intensity of coastal processes in the westerly exposed study sites, and a decrease in northerly exposed sites. Some common quasi-periodic cycles with high stage approximately in 1985-1995, and probably also from 2007 can be found. However, the role of a few randomly occurring extreme winter storms (such as in 1967, 2005, 2007 and 2012) was often decisive within the sub-periods. [ABSTRACT FROM AUTHOR]

Chaumillon E., Ozenne F., Bertin X., Long N., Ganthy F., 2014. Wave climateand inlet channel meander bend control spit breaching and migration of a new inlet: La Coubre Sandspit, France. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 109-114, ISSN 0749-0208. This study focuses on the mid-term (infra annual and pluri annual; over the period 1999-2013) morphological evolutions of a sandspit (La Coubre Sandspit, West coast of France), with a particular emphasis on spit breaching, new inlet opening and migration. Morphological evolutions are observed from a large number of aerial photographs and satellite images and are compared with wave parameters and extreme events (periods where significant wave height exceeds the 1% largest waves with water level exceeding the 90% highest water level) obtained from a high resolution hindcast wave modelling. It appears that extreme events are likely to be responsible for spit breaching and new inlet opening. Once opened, the new inlet migrates downdrift, but its migration rate is not correlated with the wave climate variations. Detailed geomorphological observations suggest that the main control on downdrift inlet migration is related to orientation of the meander bend of the tidal inlet main channel. When the meander bend is convex in an updrift direction, it counteracts the littoral drift and slows the inlet migration. Oppositely, when the meander bend is convex in a downdrift direction, the meander-induced transport is in the same direction as wave-induced longshore transport, which allows the inlet to migrate much faster. [ABSTRACT FROM AUTHOR]

Kusadasi is one of the most famous tourism centers in Turkey and encompasses agricultural, forest, natural, and coastal areas. The town has been facing rapid urbanization owing to tourism development in the region over the last 20 years. The aim of this study is to analyze and monitor the changes in land use and land cover (LULC) in the Kusadasi urban coastal area between 1993 and 2006. To do so, we will use aerial photographs (dated August 1993) and high-resolution IKONOS (dated July 30, 2001) and Quick Bird (dated July 24, 2006) satellite images. We classify LULC in the study area using manual on-screen digitizing in accordance with CORINE LULC nomenclature. Our results showed that the surface area of artificial, nonagricultural vegetated areas, arable land, permanent crops, forests, scrub, and/or herbaceous vegetation associations and open spaces with little or no vegetation decreased, whereas that of urban fabric, industrial, commercial, and transport units and mine, dump, and construction sites increased within a 13-year period. It is noteworthy that from 1993 to 2006, artificial, nonagricultural vegetated areas, permanent crops, open spaces with little or no vegetation (beaches, dunes, and sand plains) and inland waters turned into urban fabric and industrial, commercial, and transport units. One of the conclusions from the study is that, in the planning works for Kusadasi, decisions need to be made that reduce the effects of urban fabric, industrial, commercial, and transport units on artificial, nonagricultural vegetated areas and permanent crops in the coastal zone. [ABSTRACT FROM AUTHOR]

Human developments along the coastal zone have been increasing greatly during the past decades, and many of those developments are now threatened by coastal erosion. Sea cliff sensitivity to such process can be assessed in different ways, e.g. by coastal morphology, elevation, lithologies, etc. Important parameters controlling rock quality, and hence cliff stability, are its lithology and the presence and characteristics of discontinuities. In this article, a methodological approach is proposed for determining cliff characteristics and the probability of collapse, according to the Bieniawski Method, widely used in geotechnical and applied geologic studies, and for assessing the role of cliff verticality and the presence/absence of protective structures. The vulnerability of human structures depends on their distance from the cliff top, which can be expressed according to their location within the Imminent Collapse Zone and the 10-, 20-, and 30-year, predicted coastline positions obtained from aerial photographs. [ABSTRACT FROM AUTHOR]

Kim, I.H., Lee, H.S. and Song, D.S., 2013. Time series analysis of shoreline changes in Gonghyunjin and Songjiho Beaches, South Korea using aerial photographs and remotely sensed imagery Given the speed and pervasiveness of anthropogenic landcover changes, especially in coastal areas, monitoring shoreline alterations and their impacts is critical for intelligent coastal development and beach use management. In this study, we describe a monitoring and analysis framework that uses aerial photography, remotely sensed imagery, and field surveys to detect changes in beach width and area along Gonghyunjin and Songjiho Beaches in South Korea. We used IKONOS imagery acquired in 2004; aerial photographs captured in 1991, 2005, 2009 and 2010; and field surveys conducted in 2010 and 2011. Based on comparisons of these data sources, we detected widespread erosion on both beaches starting in 2004, resulting in 12% reduction in the plane area of these beaches between 2004 and 2010. Most dramatically, we noted that beach width eroded by 28.5 m at the point 700 m south of Gonghyunjin Harbor, and similar declines occurred at several other locations. Erosion occurred at these locations because extended breakwaters in the Gonghyunjin Harbor either blocked or interrupted drift sand transport processes, causing sand to be carried away from some locations without accretion to replenish it. In addition, according to field surveys, we determined that erosion and accretion processes continued to vary seasonally in 2010 and 2011, resulting in smaller overall changes than those in the study years prior to 2010. However, we suggest that severe erosion may occur in the future at some locations if sand continues to be transported north onto Songjiho Beach without replenishment. Thus, we demonstrated that the construction of artificial structures around the harbor caused changes along the shoreline. Our monitoring framework has important applications for future observation of anthropogenically driven changes to this coastal area and serves as an applicable tool in other coastal regions worldwide. [ABSTRACT FROM AUTHOR]

Cabrera-Vega, L.L., Cruz-Avero, N., Hernández-Calvento, L., Hernández-Cordero, A.I. and Fernández-Cabrera, E., 2013. Morphological changes in dunes as an indicator of anthropogenic interferences in arid dune fields. In: Conley, D.C., Masselink, G., Russell, P.E. and O'Hare, T.J. (eds.) Coastal dunes systems have been widely modified by human activities, especially in recent decades. Some of the changes have modified the aeolian landforms which characterize these environments. The dune systems of the Canary Islands can be considered as arid systems due to its temperature and rainfall levels. For this reason, the speed at which the geomorphologic process (natural or induced by human activities) occur are more significant than in dune systems located at either temperate or tropical regions. In this sense, the Canary Islands beach-dune systems are ideal for testing the effects of human activity on these environments. This work identifies major alterations, from the 60's, on three dune systems where the tourism activity has developed to a considerable extent: Maspalomas (Gran Canaria), Corralejo (Fuerteventura) and Famara (Lanzarote). To analyse these changes, historical and current aerial photographs and orthophotographs were used, as well as field work. Changes have been classified by the causes that induced them: I) urban development; II) beach equipment; III) beach users; IV) maintenance activities; V) a combination of some of these former causes. Results indicate that urban development is the main cause of the alteration of these dune fields. In Maspalomas and Famara less than 35% of their surfaces are free of human actions capable of producing morphological changes, while in Corralejo this percentage reaches 63%. In the analyzed period, the surface of the dune fields have been reduced, some of the existing dunes have been modified, and new morphologies (natural and artificial) have appeared. The latter process is mostly associated with mismanagement in these areas. [ABSTRACT FROM AUTHOR]

Del Río, L., Gracia, F.J. and Benavente, J., 2013. Morphological and evolutionary classification of sandy beaches in Cadiz coast (SW Spain). Sandy beaches are extremely dynamic systems, so gaining insight about decadal patterns of beach change is essential for the adequate management of risks affecting coastal zones. This work aims at improving understanding of the factors that control erosion-accretion processes and evolution of sandy beaches at the intermediate time scale. For this purpose, recent evolution of beaches along the 150 km long Atlantic coast of Cadiz (SW Spain) is investigated in relation to their morphology and dynamics. Dune toe and high water line changes are assessed based on georectified aerial photographs from 1956-2008, using GIS tools. Results show considerable spatial and temporal variability of recent shoreline changes along the study area, with mostly eroding trends along the northern sector and a predominantly stable southern sector. Important exceptions at certain points are related to the heterogeneity of the coast and the diverse natural and anthropogenic factors contributing to shoreline change in the area. A classification of the studied beaches is proposed, based on beach morphology and dynamics, thus helping to understand the way coastal morphological characteristics influence erosion-accretion trends. Rectilinear beaches are predominantly stable or accreting, whereas reef-supported beaches are mostly erosive. Z-bays generally experience erosion at one end and accretion at the opposite end, greatly influenced by local conditions. Enclosed beaches are stable where sediment budget remains unchanged, but rapidly erode or accrete if human interventions alter the balance. The classification allows identifying those beaches which are most sensitive to variations in controlling factors, such as sediment supply. [ABSTRACT FROM AUTHOR]

Shoreline change was measured along the beaches of Kauai, Oahu, and Maui (Hawaii) using historical shorelines digitized from aerial photographs and survey charts for the U.S. Geological Survey's National Assessment of Shoreline Change. To our knowledge, this is the most comprehensive report on shoreline change throughout Hawaii and supplements the limited data on beach changes in carbonate reef-dominated systems. Trends in long-term (early 1900s- present) and short-term (mid-1940s-present) shoreline change were calculated at regular intervals (20 m) along the shore using weighted linear regression. Erosion dominated the shoreline change in Hawaii, with 70% of beaches being erosional (long-term), including 9% (21 km) that was completely lost to erosion (e.g., seawalls), and an average shoreline change rate of − 0.11± − 0.01 m/y. Short-term results were somewhat less erosional (63% erosional, average change rate of − 0.06 ± 0.01 m/y). Maui, Hawaii, beaches were the most erosional of the three islands with 85% of the beaches erosional, including 11% lost, and an average change rate of -0.17 ± 0.01 m/y. Seventy-one percent of Kauai, Hawaii, beaches were erosional, including 8% lost, with an average change rate of -0.11± 0.01 m/y. Most (60%) of the Oahu, Hawaii, beaches were erosional, including 8% lost, with an average change rate of -0.06 ± 0.01 m/y. Short-term results for Maui, Hawaii, and Oahu, Hawaii, were roughly the same as those found in the long term. Short-term analysis for Kauai, Hawaii, was less conclusive with an accretional average rate, but most of the beaches were erosional. Spatially, shoreline change is highly variable along the Hawaii beaches (length scales of hundreds of meters). Areas of chronic erosion were identified on all sides of the islands. [ABSTRACT FROM AUTHOR]

Coastal areas are naturally dynamic with changes occurring over periods of time. When the shoreline moves landward, coastal erosion becomes a serious problem, and the rate of change has to be calculated. Coastline retreat is one of the best indicators of coastal erosion. Here, the geographic information systems (GIS) platform (ArcGIS® 9.3.1; Esri software) is used to study the long-term (last 59 years) shoreline change in the area of Hardelot-Plage and Sainte Cécile-Plage (a north-south 14-km-long beach), in northern France. The primary aim of this study was to develop a methodology for calculating shoreline change using ArcGIS Modelbuilder and aerial photographs. Changes in 14 coastlines over the course of 59 years (from 1946 to 2005) were digitized and represented in ArcGIS 9.3.1 platform. Two hundred and ninety-two transects perpendicular to the shoreline were used to estimate coastal erosion and deduce the recession rate. The Modelbuilders (two models) created and used in this work are generic models that can be used for geoprocessing linear features. One model can be used to ascertain the intersection between linear features (transects and shorelines), adding a new field to the attribute table and calculating the geometry of the intersection points. A second model can be used to add a new field to the attribute table and calculate the distance on the transect lines between the linear reference feature and other linear features, in this study between the baseline (established adjacent to the series of shoreline positions) and the shoreline. The results show that the shoreline change rates between 1947 and 2005 along the Hardelot and Sainte Cécile coasts are generally negative; 82.2% of transects have values less than zero (i.e., retreat) and outside of the error margin (±10 m). Nevertheless the shoreline change shows successive phases of advance and retreat over the same period. [ABSTRACT FROM AUTHOR]

Beach hydromorphological classification is a complex subject. Different beach classification models were presented by several authors. However, fundamental parameters are usually unavailable. Therefore, a morphological analysis using remotely sensed data and image processing techniques is a good approach to identify and to classify beach hydromorphologies. Remote sensing data is an increasingly important component of natural resources monitoring programs. Its usefulness can be maximized by understanding the constraints and capabilities of the imagery and change detection techniques, related to the monitoring objectives. The aim of this study was to explore different remotely sensed data (aerial photographs and a satellite image) and different image processing algorithms in order to identify coastal forms/patterns and further classify beach hydromorphological stage. To achieve that, different image processing techniques were applied to remotely sensed data: pixel and object-based classification algorithms and a pattern recognition approach using artificial neural networks. A stretch of the northwest coast of Portugal was chosen as the study area. The data used in this study consisted in aerial photographs and an IKONOS-2 image. Based on the obtained results two main conclusions could be taken: the pixel-based classification (supervised classification algorithms) showed better results than the object-based classification algorithms; and the pattern recognition approach is the most effective and accurate methodology. Therefore, the association of remote sensing data and image processing techniques is very useful in identifying coastal forms/patterns regarding the classification of beach morphological stage. [ABSTRACT FROM AUTHOR]

Information regarding the present condition, historical status, and dynamics of mangrove forests is needed to study the impacts of the Gulf of Mexico oil spill and other stressors affecting mangrove ecosystems. Such information is unavailable for Louisiana at sufficient spatial and thematic detail. We prepared mangrove forest distribution maps of Louisiana (prior to the oil spill) at 1 m and 30 m spatial resolution using aerial photographs and Landsat satellite data, respectively. Image classification was performed using a decision-tree classification approach. We also prepared land-cover change pairs for 1983, 1984, and every 2 y from 1984 to 2010 depicting ''ecosystem shifts'' (e.g., expansion, retraction, and disappearance). This new spatiotemporal information could be used to assess short-term and long-term impacts of the oil spill on mangroves. Finally, we propose an operational methodology based on remote sensing (Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer [ASTER], hyperspectral, light detection and ranging [LIDAR], aerial photographs, and field inventory data) to monitor the existing and emerging mangrove areas and their disturbance and regrowth patterns. Several parameters such as spatial distribution, ecosystem shifts, species composition, and tree height/biomass could be measured to assess the impact of the oil spill and mangrove recovery and restoration. Future research priorities will be to quantify the impacts and recovery of mangroves considering multiple stressors and perturbations, including oil spill, winter freeze, sea-level rise, land subsidence, and land-use/land-cover change for the entire Gulf Coast. [ABSTRACT FROM AUTHOR]

Most migrant shorebirds require coastal and estuarine habitat in the nonbreeding season and their overwinter survival is contingent upon the composition and quality of these winter sites. The purpose of this study was to investigate the relationship between the distribution and abundance of the piping plover, a federally threatened and endangered shorebird, and its nonbreeding habitat along the Gulf of Mexico coastline. We identified sites consistently used by wintering piping plovers and quantified landscape and anthropogenic features within a subset of those locations. Using published literature, we documented that piping plovers consistently winter at 49 locations on the U.S. Gulf of Mexico coast (Marco Island, Florida to Padre Island, Texas). At 31 sites, we conducted a remote analysis of aerial photos for 11 features (e.g., intertidal area, urban area, beach). Linear regression was used to test correlations between plover abundance and landscape characteristics. We found that certain shoreline features (e.g., landform, inter-tidal area, total area) and measures of urbanization (e.g., urban area, length of roads) were significantly correlated, positively and negatively, respectively, with piping plover abundance across the Gulf of Mexico coastline. This information is critical to prevent or mitigate negative impacts of urbanization and subsequent coastal landscape change on shorebird populations. [ABSTRACT FROM AUTHOR]

Cabo Falso is located on the southern coast of the Baja California peninsula. The beach is broad and wide with a steep face and tall foredunes on the backshore. Landwards, an active, predominantly parabolic dune field has developed with average heights of 30 m. Part of the field is used by recreational all-terrain vehicles. The main goal of this study was to identify the principal morphodynamic characteristics of the deposits influenced by these recreational activities and affected by Hurricane Juliette in 2001. The morphology of the study area was monitored using seasonal topographic profiles, examination of aerial photographs from 1972 and 1993, and on-site photographs (November 1999 to April 2002). The topographic profiles indicated that the erosion period for both the beach and the dunes was June to December. Hurricane Juliette was the responsible for most of the observed erosion. The greatest sediment accumulation occurred between December 2001 and February 2002, associated with the onset of the natural recovery process of the beach-dune system. The photographs revealed that the dunes have lost vegetation cover because of the activities of all-terrain vehicles, which erode paths perpendicular to the dune crests. This in turn allows increased sediment movement, resulting in instability of the dune field system. [ABSTRACT FROM AUTHOR]

Over the past 20 years, fractal geometry has gained acceptance as a valid quantitative method for describing complex geomorphic patterns in nature. One goal of geomorphology is to relate geologic processes to the development and evolution of landforms. The processes (factors) that shape a landform might produce a characteristic geometry that can be interpreted through fractal analysis. The geometry of a shoreline is often cited as an example of a fractal pattern. Previous studies on shoreline geometries have used relatively small-scale maps and aerial photographs, and have not studied the changing geometry of a shoreline over time. This study, in contrast, examines the fractal geometry of six wave-dominated marsh shorelines in Rehoboth Bay, Delaware, at a relatively large scale, and investigates how these geometries change over time. The results help to understand the relation between geomorphic features and processes. An automated box-counting method was used to calculate fractal D values for each shoreline. D values ranged from 1.01 to 1.19, which are lower than previous shoreline studies. The greater D values are associated with sites that experienced the greatest wave erosion. Furthermore, the geometric complexity of these shorelines did not change over 3 years. In comparison, D values obtained from a tide-dominated marsh shoreline were greater (1.27), suggesting that the dominant formative process (e.g., tides vs. waves) may be distinguished through geometric analysis. However, to use fractal data as a comparable geomorphic tool, it is necessary to choose features of a similar size (scale) and from a similar geomorphic setting. In this way landform complexity (D) is likely due to either (1) the type of shaping process in different geographic settings, or (2) the magnitude of a single shaping process within a single geographic setting. [ABSTRACT FROM AUTHOR]

Four sets of maps and aerial photographs have been integrated into a Geographic Information System (GIS) project to investigate coastal changes along a 60-km-long littoral sector in south Sicily, Italy. The beaches studied recorded significant morphological changes essentially related to the presence of human structures that interrupted littoral drift. Most of the investigated beaches experienced progressive erosion because of sediments being trapped by human structures resulting in the formation of wide beaches on the updrift side and erosion downdrift. The latter has often been counteracted by the construction of breakwaters. However, local planning authorities did not carry out an assessment of the impacts related to the construction of harbours and ports and their successive enlargement. This article proposes alternative actions concerning the possible future erosion management of the studied littoral. [ABSTRACT FROM AUTHOR]

The evolution of the barrier-spit terminus of Skallingen was analyzed on navigational charts and aerial photographs. Between 1654 and 1905, the barrier spit Skallingen built up from a nonvegetated dry sandy ridge to exhibit extensive aeolian dune ridges. After 1910, the barrier-spit terminus slowly started to erode and, between 1945 and 2000, barrier-spit terminus eroded almost 2 km toward the northwest, in the opposite direction of the littoral drift. Cut-off of the sediment bypassing and dredging of the tidal channel is found to be the main reason for erosion of the barrier-spit terminus. Storms have affected the west coast of Skallingen and its barrier-spit terminus very differently, as most erosion at the terminus took place before 1981 and erosion on the west coast mostly took place after 1981. Contemporary with the erosion, a flood tidal delta appeared and it has migrated 1740 m since 1974. The front of the flood tidal delta has increased in height and is close to mean high water spring, and about 380,000 m³ of sediment was deposited within this flood tidal delta east of Skallingen between 1990 and 1999. [ABSTRACT FROM AUTHOR]

A primary purpose of this paper is to quantitatively link variously defined and derived shoreline estimates commonly used for shoreline change analysis. Estimates of shoreline mapping and derivation error, natural shoreline variability, and the relationships between horizontally-derived (proxy-based) shorelines to vertical datums (e.g. MHW) are presented. A series of shoreline repeatability and variability experiments as well as data from a beach monitoring program along the high-energy US Pacific Northwest coast, indicate total uncertainty estimates of the horizontal position of proxy-based shorelines to be approximately ± 50-150 m for T-sheets and aerial photography and approximately ± 15 m for datum-based shorelines derived from ground- or air-based topographic surveys. The ability to obtain reliable shoreline change results depends upon both the selected shoreline definition (e.g. horizontal- or feature-based proxy, or datum-based intercept) and the accuracy of the technique used in mapping or interpreting its position. The position of the selected shoreline on the beach profile determines its inherent temporal and spatial variability, an imporrant consideration that has often been overlooked in the scientific literature on shoreline change. Historical shorelines mapped on NOS T-sheets and aerial photos have commonly identified high water line (HWL)type shorelines, which are shown to be higher on the beach surface than the MHW-datum intercept along coasts subject to wave runup. Analyses of 4.5 years of beach profile data from the southwest Washington coast suggest that both the MHW and HWL-type shorelines have greater natural short-term variability than expected, significantly greater than the variability of shoreline proxies defined farther landward and higher on the beach profile. A model for determining the natural variability of HWL-type shorelines reveals that this short-term variability is the dominant factor in the large total uncertainty values associated with shorelines derived from T-sheets and aerial photographs. The results of these analyses and quantitative comparisons are relevant to determining the significance of historical shoreline changes, as well as to defining the appropriate shoreline proxy or datum and time scale for future shoreline change analysis. [ABSTRACT FROM AUTHOR]

Shoreline salients are low triangular landforms, which project seaward as promontories. The term tombolo is applied when this landform is joined to an island or obstacle. This work presents a literature review of salients and tombolos, with a classification of singular landforms, and discusses the relationships between morphological parameters. It also analyses the planform of these features (sigmoid model and parabolic model) on the coast of the State of Santa Catarina in the south of Brazil. Interpretation of aerial photographs and topographical maps enabled the identification of 15 tombolos and 10 salients. The observed proportions and the symmetry of these landforms are directly related to the geological conditions and predominant wave direction. For salience data, regressions between X/B and B/S presented an R2 of 0.79. Regressions between the obstacle depth (d) and the average length of incident waves were obtained, and the results (B*d / (L2) ~ S*d / (L2)) exhibited high R2 values (0.83 and 0.80) for salients and tombolos for data in the literature. The parabolic model was found to be suitable in the analysis of the planform shape of the feature as this model incorporates geometric and dynamic (wave direction) variables. [ABSTRACT FROM AUTHOR]

Jeong, J.B.; Woo, H.J.; Jung, H.-S.; Park, H.N.; Kim, T.-J, and Lee, J.-H., 2021. Monsoon-influenced deposition systems in a rhodolith beach on Udo Island, Korea. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 41–45. Coconut Creek (Florida), ISSN 0749-0208. A beach on Udo Island, off the coast of Jeju Island, Korea was formed by long-term deposition of rhodoliths, which comprise more than 99% of all deposits on the beach. This phenomenon is very rare on the global scale. This rhodolith beach in 2004 was designated a natural monument to preserve its geoheritage. However, to date, no geological studies have been conducted to examine its sedimentary mechanisms and properties. Recent tourist developments and climate change have raised the possibility of erosion on the rhodolith beach. The objective of the present study was to examine the evolution and sedimentation characteristics of this beach through analysis of grain size and aerial photographs, and seasonal beach surveys. Geomorphologically, the beach is divided into reef areas to the north, with high altitudes and rocks mainly distributed along the coastline, and sandy beach to the south, which is strongly affected by waves and tidal currents. Particle sizes decrease toward the upper part of the beach, with gravel-sized sediments in the south and sand-sized sediments in the north. The mean grain size of deposited sediments increases from spring to autumn. In spring, the beach experiences greater erosion in the north and deposition in the south, whereas in summer, the opposite trends are seen. The sediment deposition volume is largest in autumn. There is also annual variation, where the beach was dominated by erosion in three recent years due to a decrease in sediment volume toward the south. The beach increased in volume from 1985 to 2003, and decreased thereafter. Due to the influence of the East Asian Monsoon, the beach experiences typhoons in summer and north-northwesterly waves and tidal currents in autumn and winter. However, erosion occurs in in the south due to a lack of berm for rhodoliths deposition. [ABSTRACT FROM AUTHOR]

The article provides information on the challenges encountered in two projects in contrasting environments in two different Australian states. It discusses the biggest problem encountered in investigating the evolution of the LeFevre Peninsula in South Australia and the challenges encountered in investigating the sedimentary evidence for Holocene sea-level change on the eastern shores of Cleveland Bay, north Queensland.

Díaz-Cuevas, P.; Prieto-Campos, A.; Fraile-Jurado, P.; Ojeda-Zújar, J., and Álvarez-Francoso, J.I., 2020. Shoreline "proxies" evaluation for mid-term erosion rates calculation in mesotidal and microtidal beaches (Andalusia, Spain). In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1062–1066. Coconut Creek (Florida), ISSN 0749-0208. Coastal erosion is closely linked with the concept of sedimentary balance and traditionally is considered a relevant variable for the assessment of changes related to loss of sediments (usually computed as shoreline retreat). Nevertheless, coastal erosion can be examined through a wide variety of methodologies, each of which has its own characteristics and aims. The 3D (volumetric) method is currently the most accurate, but the lack of historical data series makes difficult a mid/long-term analysis of the phenomenon, so most studies rely on one-dimensional or bi-dimensional analysis based on aerial photographs and the use of indirect indicators (proxies), such as shoreline oscillation, using generally, the mark left by the high water line and, less frequently the backshore/foredune contact. This paper examines different proxies for the analysis of erosion rates in the mid-term in the Andalusian coast, which are exposed to different morphodynamics processes (one is in the Atlantic coast and the other one in the Mediterranean coast). In order to do this, different proxies have been digitized at a 1:2500 scale, and the erosion rates have been calculated for the period 1977-2013. The results suggest that, in general, the use of the backshore/foredune proxy is consistent, especially in Atlantic beaches (mesotidal), while the high water line proxy is used in Mediterranean beaches (microtidal), as long as the morhodynamics conditions remain homogeneous (summer season) for the dates of ortophotographies. However, the erosion rates calculated with proxies in this way should be taken with caution and supported by additional evidence for adequate interpretation. [ABSTRACT FROM AUTHOR]

Moulton, M.A.B.; Hesp, P.A.; Miot da Silva, G.; Keane, R., and Fernandez, G.B., 2020. Effects of the increase in vegetation cover and impact of rabbits on the geomorphology of parabolic dunes (Younghusband Peninsula - SA, Australia). In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 108-112. Coconut Creek (Florida), ISSN 0749-0208. This study examines the geomorphological changes that occurred in a large parabolic dune on the Younghusband Peninsula (YP) dune system (South Australia) due to changes in vegetation cover in the past ∼70 years. Recent studies have shown that vegetation cover has significantly increased due to the control of exotic rabbits by introducing Myxomatosis (1950's) and Rabbit Haemorrhagic Disease Virus (1990's and 2000's). Using a sequence of historical aerial photographs between 1949 and 2018 and LiDAR data (2018), changes in the geomorphological evolution of a typical parabolic dune were analyzed. In 1949 a well-developed transgressive and parabolic dunefield connected to the beach was present. In 1975 (26 years later), the parabolic dune analyzed here experienced partial stabilization by the increase in vegetation cover on the deflation basin and on top of the depositional lobe, where nebkha dunes started to develop. Vegetation of the nebkha eventually connected to the vegetation of the deflation basin, separating the parabolic dune into two. In 2018, a major stabilization of parabolic dunes, now disconnected from the beach by high foredunes, together with an increase of vegetation in the nebkha fields, deflation basin and in the interdune depression were observed. Although a gradual reduction in bare sand area within the parabolic dune and deflation basin was observed, demonstrating a clear stabilization process in the period analyzed, a significant increase in dune migration rate was observed between 1984 and 1995 (9.6 m/y), with was only acceded by the initial period 1949-1956 (14.6 m/y). These two periods correspond to times when European rabbit populations were highest in the YP, suggesting that these exotic herbivores played a significant role in the geomorphological evolution of parabolic dunes. [ABSTRACT FROM AUTHOR]

Sennes, G., Castelle, B., Bertin, X., Mirfenderesk, H. and Tomlinson, R.B., 2007. Modelling of the Gold Coast Seaway tidal inlet, Australia. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 1086 – 1091. Gold Coast, Australia, ISSN 0749.0208 The Seaway entrance is a tidal inlet located on the Gold Coast (Queensland, Australia). Before the 80s, the entrance was highly variable in terms of inlet location and sand bar characteristics. The Seaway stabilisation with two training walls combined with an artificial sand bypassing system were completed in 1986 with the aims of fixing the entrance, maintaining a safe navigable channel, preventing shoreline erosion to the north and a buildup of sand to the south. Despite these training works, the dynamics of the Seaway is still poorly understood: channel infilling problems and navigation issues remain. For these reasons, the present study aims to develop a comprehensive model of the entrance to be used for further dredging and training work issues. The present investigation is carried out in two stages. The first stage is based on historic aerial photograph analysis of the Seaway before training works. It shows that the mouth was periodically driven northward by the longshore drift, with an average cycle time of 10 years. The second stage is based on numerical modelling after training works. Refined Delft3D modelling is undertaken with a 2DH approach on the Seaway area, taking into account the training walls and the sand bypassing system. This local model is coupled with MIKE21 implemented on a regional scale to provide accurate tide and flow forcing at the boundaries. After calibration, the analysis of flow patterns shows that the Gold Coast Seaway is ebb-dominated and that the more intense flow velocities are observed in the northern channel. Morphological evolution of the inlet is also investigated with a qualitative approach. Results indicate the pathways and rate of the sand movement within the tidal inlet in its current configuration and provide information about a planned 400 m extension of the southern training wall. A significant calibration work, involving sediment transport and bathymetry measurement, is required for the model to be used as a comprehensive tool for further dredging and dumping strategies within the entrance. [ABSTRACT FROM AUTHOR]

Bezerra, M.O., Pinheiro, L. and Morais, J.O. 2007. Shoreline Change of the Mucuripe Harbour Zones (Fortaleza-Ceará, Northeast of Brazil) 1972 - 2003. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 1163 – 1167. Gold Coast, Australia, ISSN 0749.0208 This study analyses the space-time evolution along the Fortaleza coast over the past 31 years (1972-2003) with a special emphasis on the Mucuripe port area (Fortaleza, Ceará, Brazil) examining changes in the coastal dynamics produced by the building of the city's port. The construction of the port's jetty interrupted the natural feeding process of the beaches with sediment moving east to west. Sediment was blocked east of this structure leading to an erosion process to the west. This multi-temporal study is based on the analysis of aerial photographs and images from the Quickbird satellite. The objective is to determine the recent evolution of this coastline through calculation of the variation in retrograding and prograding areas. The variation of the city of Fortaleza's dune-beach interface shoreline, which concerns an extension of approximately 30 km of shoreline, revealed a prograding rate of 0.8284 km2/31 years (1972/2003) and a retrograding rate of 0.0701 km2/31 years (1972/2003). Analysis of images of Mansa Beach, located in the Mucuripe port basin, showed that in 1972 Mansa Beach had an area of 0.13843 km2, in 1998 it increased to 0.15307 km2 and in 2003 it reached 0.15455 km2. The analysis revealed that the changes in the shoreline are more subject to shoreline accretion. The analysed period shows a 92% accretion rate and an 8% erosion rate. The results contribute to the improved management of the Fortaleza coast. [ABSTRACT FROM AUTHOR]

Costas, S. and Alejo, I., 2007. Local and Global Influences on the Evolution of a Transgressive Sand Barrier: Cies Barrier, Northwest Spain. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 1121 – 1125. Gold Coast, Australia, ISSN 0749.0208 The decadal evolution and the factors that control the variability of a recent welded barrier located in the northwest of Spain have been investigated. Analysis of the morphological changes and the evolution of the shoreline were carried out using georectified aerial photographs spanning from 1949 to 2003. The barrier shows a complex temporal and spatial behavior. Erosive and constructive, or accretionary stages, alternate over time giving rise to a cyclical evolution. Shoreline behavior differed according to geomorphic setting. In regards to the spatial behavior, the shoreline presented different response patterns depending on the presence of dunes, cliffs or an inlet. The evolution of the sand barrier was related to the effect and variability of global (sea level and climate change) and local factors (storm regime or sediment input). Despite some cyclic behavior between 1949 and 2003, the net shoreline position moved landward approximately 24 m. This was associated with inlet relocation and lagoon infilling. Despite the episodic behavior of the shoreline from 1949 to 2003, the barrier receded around 24 m causing important morphological changes such as the adjacent lagoon infilling or inlet relocation. The evolution of the sand barrier seems to result from the combined effect of different factors such as sediment scarcity, wave exposure, climate oscillation or mean sea level rise. These factors interact so that their combined effect is greater than the sum of their individual effects. [ABSTRACT FROM AUTHOR]

Truong, T.K. and Tanaka, H., 2007. Effects of a river mouth terrace to longshore sediment transport. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 874 – 878. Gold Coast, Australia, ISSN 0749.0208 Recently, beach erosion has become a concern in Japan. Much research has studied the balance of sediment transport and influencing factors, but the influence of river mouths has rarely been of concern. For a coast including an estuary, river mouths can be seen as a source of sediment supply. However, for the case where a consolidated river mouth terrace exists, the longshore sediment transport can be intercepted, as well as the effect of jetty. Therefore, the existence of a river mouth terrace is not only the source of sediment but also intercepts the longshore sediment transport. To estimate these problems, a wide data of the river mouth and surrounding coast was used. The study area includes the Nanakita River mouth, located in the northern part of the Sendai coast, northeast Japan. Aerial photographs, taken every two months from 1990 to 2005, were used to analyze the shoreline changes and the effect of the Nanakita river mouth on longshore sediment transport. The results show that after 1998, the Nanakita river mouth terrace had no further effect of blocking the longshore sediment transport. [ABSTRACT FROM AUTHOR]

Pais-barbosa, J., Veloso-gomes, F., and Taveira-pinto, F, 2007. Coastal features in the energetic and mesotidal west coast of Portugal, SI 50 (Proceedings of the 9th International Coastal Symposium), 459 – 463. Gold Coast, Australia, ISSN 0749.0208 The Portuguese west coast can be classified in three morphological groups: sandy coast, low rocky coast and cliff coast. This coastal zone is very energetic (wave-dominated) and is undergoing severe erosion, especially on the sandy coast. The study area is characterised by an extensive sandy flat area, very dynamic and environmentally fragile, under a mesotidal regime. The main objective of this paper is to identify and classify morphologically (e.g. megacusps, bars, cuspate shorelines, beach cusps) and hydrodynamically (wave breaking, surf-zone processes, rip currents, littoral drift) coastal patterns, based on the analysis of aerial photographs datasets. The identified features and coastal patterns will be compared with the existent morphological beach models and classifications. The preliminary analyses allow the identification of several morphological features such as megacusps; shore attached oblique bars, crescentic bars, cuspate shorelines and beach cusps, as well as the associated hydrodynamic currents. A certain similarity with other tidal regimes (microtidal) was found but in some cases with different spatial scales. [ABSTRACT FROM AUTHOR]