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Psuty, N.P.; Ames, K.; Liu, G., and Habeck, A., 2020. Interactive geomorphological resilience of sediment pathways and coastal features, post-Hurricane Sandy, Fort Tilden, New York. Journal of Coastal Research, 36(4), 694–708. Coconut Creek (Florida), ISSN 0749-0208. Geomorphological resilience is an essential concept in dynamic coastal systems, incorporating the recovery and regeneration of the dune/beach system and the interaction between these systems, anthropogenic forces, and ecological factors. Recovery of the coastal geomorphological system at the Fort Tilden site after Hurricane Sandy was influenced by the wooden bulkhead and the variety of groins interacting with the sediment budget. Monitoring of the recovery revealed that the alongshore coastal dune/beach system response (one-dimensional, two-dimensional, and three-dimensional metrics) was strongly related to the 11 groin sectors and that the total volume losses increased downdrift. Hurricane Sandy resulted in a general inland displacement of the dune feature along the entire site, mean of –32 m, and a landward displacement of the shoreline, mean of –3 m. There was a volumetric loss of 81,000 m3; 29,000 m3 of this was from the dune feature. Post-Sandy to Fall 2018, the dune was displaced 2 m seaward and had a volumetric gain of 10,580 m3. Comparison of the dune displacement and sediment budget metric indicated that through the six-year recovery period, the dune feature was accumulating sediment but that it was not shifting seaward to its former position despite updrift beach nourishment totaling ∼3,180,000 m3 in the period 2010–18. The inland displacement and retention of the beach-dune system under a negative sediment budget is consistent with geomorphological theory, indicating a geomorphological resilience to rebuild while shifting inland. Accordingly, the former position of Shore Road along Fort Tilden is deemed unsuitable for reconstruction in place because of increased exposure in the Post-Sandy environment. [ABSTRACT FROM AUTHOR]

The trend and episodes of erosion at Great Kills Park, part of the National Park Service, are products of the origin of the park's location and the impact of a negative sediment budget. Management response to the impacts of erosion is somewhat limited by National Park Service philosophy, but some options remain because the negative sediment budget is a product of barriers to sediment transport updrift of the Park. The erosional situation is exacerbated by an exposure of an antecedent backmarsh feature within the Park that is affecting the inshore pattern of incident waves. Recent monitoring data indicate planform conformity to an updrift log-spiral erosional bluff that extends downdrift to a site with beach and dune features. Despite a general net negative sediment budget in the profile, the dune feature is increasing in volume as it shifts inland, fitting models of foredune development. Seasonal monitoring of the topography records that storms cause a stepwise inland displacement of an updrift portion of the Park and a more linear displacement in the downdrift portion. Among the options consistent with management policy responding to the negative sediment budget issue is an opportunity to work within the scale of the small sediment transport cell and backpass sediment toward the updrift margin of the cell. [ABSTRACT FROM AUTHOR]

The geomorphological map offers a snapshot of the landforms generated through topographical response to physical process drivers within a given landscape. A comparison of geomorphological maps with consistently and objectively identified landform boundaries allows for the assessment of spatiotemporal variations in process-response dynamics that represent the fundamental nature of geomorphological evolution, and form a basis to derive quantitative metrics of landform development. Two geomorphological maps of Fire Island National Seashore created from LiDAR datasets and orthophotography collected prior to and immediately following Hurricane Sandy were compared according to consistent and objective criteria. The mapped geomorphology and the LiDAR elevation data facilitated the use of regional-residual separation methods to assign sediment volumes to specific processes and landforms. This led to the calculation of sediment volumes deposited as beaches, foredunes, and washover deposits before and after the storm and to the quantification of the changes associated with the storm across the entire 50 km stretch of barrier coastline that comprises Fire Island. The temporal comparisons indicated that different portions of Fire Island exhibited variable geomorphological responses to a major storm. Notably, the central and western portion of the island, from 6 km to 36 km from the mouth of Fire Island Inlet, experienced substantial losses to coastal dunes — on the order of 2.9 × 106 m3 of sediment. The beaches in this segment of the coastline gained volume (~86,000 m3) in the storm indicating that the dunes provided a source of sediment to the beach, both buffering erosion and supplying sand to the littoral system. The eastern third of the island experienced beach erosion (~540,000 m3) and erosion of the dunes (~350,000 m3), as well as a significant amount of overwash deposition (~250,000 m3) that represents a transfer of sediment from the beach/dune reservoir to the backbarrier. This mode of geomorphological evolution adds elevation to the backbarrier at the expense of sediment available to buffer the shoreline position. Two 6 km strecthes of Fire Island coastline, Bellport/Old Inlet and Talisman/Watch Hill, exemplify the geomorphological response of the eastern and central potions of the island to the impact of Hurricane Sandy: 1) at Bellport/Old Inlet, overwash deposition was partially sourced from beach deposits adding elevation to the backbarrier at the expense of the shoreline position; and 2) at Talisman/Watch Hill, sediment stored in dune systems was transferred to the beach to slow storm induced shoreline retreat, and the dune buffer and its associated resilience was reduced. In quantifying the system response of a barrier island to a major storm event like Hurricane Sandy, we demonstrate the feasibility and utility of deriving metrics of geomorphological change from geomorphological maps. This approach of quantifying process-response outcomes through mapping is broadly applicable to a variety of geomorphological settings and timescales given a consistent means of boundary determination and using regional-residual separation. [ABSTRACT FROM AUTHOR]

The coastal geomorphological processes of alongshore transport and tidal currents are interacting with the attendant influences of sea-level rise and sediment supply to generate morpho-sedimentary units in selected estuarine systems. Constrained by the conditions promoted by microtidal situations in barrier island settings, vectors of sediment transport have established spatial sequences of morphologies and sediment types that are components of shellfish habitats. Greater depth and decreasing grain-size toward the mainland are common characteristics in five northeastern U.S. estuarine systems. The patterns are repeated at various scales among the lagoon-type estuaries as well as within the estuarine settings to establish geospatial associations of geomorphology and habitat. [ABSTRACT FROM AUTHOR]

The habitats of La Mancha Lagoon, located midway along the coast of Veracruz, Mexico, are responding to the change of sediment supply reaching its primary inlet at the Gulf of Mexico. Until several decades ago, an abundant alongshore supply of sediment created a periodic opening and closing of the La Mancha inlet. The hydrologic regime of the lagoon consisted of raised water level and lower salinity during the closures, whereas the open inlet favored lower water level, higher salinity, and sediment accumulation in the flood tidal delta. Currently, diminished alongshore sediment supply has affected the inlet morphology and the discharge regime. Associated with the reduced sediment supply, the inlet is open longer in its periodic cycle, the water level variation is reduced, the salinity contrasts are reduced, and the rate of sedimentation in the flood-tide delta is increased. This combination of alterations to the inlet area is changing the flooding regime and affecting the conditions in a very well-developed mangrove habitat at the lagoon margins as well as conditions within the aqueous portions of the lagoon. Management options produce a conflict between supporting the direction of change or preserving the existing habitats. [ABSTRACT FROM AUTHOR]

Abstract: A century of human manipulation of sediment transport and sediment supply at Sandy Hook spit has generated an evolving suite of geomorphological responses and shoreline management approaches at this public coastal resource. Eventually a major erosion problem was created in a portion of the Gateway National Recreation Area knows as the “Critical Zone”, a location immediately downdrift of the end of a lengthy seawall. In the last three decades, the management approach was to apply beach nourishment to replace the eroded volumes. Projects emplacing from 20000 m3 to 1.7 million m3 of sand in the Critical Zone attempted to counter the erosional trend. However, evolving Park policy sought to identify alternatives to the massive emplacements of sand from offshore sources. Starting in 1997, detailed topographical surveys were begun to track sediment budget in the eroding Critical Zone, and subsequently at Gunnison Beach, a site of sediment accumulation. A new management philosophy of smaller scale restoration of sediment supply in the Critical Zone has emerged. At present, the Gunnison Beach area on Sandy Hook is being monitored to determine its potential for sediment backpassing to the Critical Zone as a means to balance its local sediment budget, create a relatively consistent topography, and maintain the recreational resources. [Copyright &y& Elsevier]

The article discusses the contributions of Jim Allen as coastal geomorphologists at the U.S. National Park Service. Allen devoted his career in scientific inquiry, evaluation of management actions and activities, conservation of coastal national parks' heritage. He is considered as an expert in causes and forecasts of shoreline change, beach/dune dynamics, historical alterations, coastal habitat and evolution of geographical information system. His efforts have tremendous impact on coastal parks in the eastern U.S.

Examines the eolian transport triggered by beach nourishments in Riells, Spain. Geomorphological impacts associated with eolian processes; Sediment mobilization within the nourishment area; Coastal sedimentation.

Studies the Holocene sedimentation and sea level rise in the Sado estuary in Portugal. General geomorphologic developmental history of the Sado estuary; Features of cores along the southern margin of the estuary; General characteristics of the sediment types; Results from carbon dating.

From its ancestral home in Indo-Burma, the mango was spread into the Western Hemisphere by the Portuguese and Spanish during the period of exploration and discovery. It was brought into Florida over a century ago and, through intermittent periods of wax and wane, mango production has become concentrated on the crestal portions of a Pleistocene limestone surface in southeastern Dade County. The Pleistocene surface, however, is also highly valued for residential development, and the mango groves are gradually being converted to urban land use. Although the groves are being displaced, many trees are retained in the urban setting and continue to produce fruit for the commercial market. [ABSTRACT FROM AUTHOR]

The largest Gulf coast alluvial plain in Mexico lies primarily in the state of Tabasco. Although predominantly a fluvial-deltaic plain the coastal landforms contribute beach-ridge topography which extends inland up to twenty miles. Beach ridges attain fullest development adjacent to distributory channels and reflect periods of active discharge. Trenching of the ridges disclosed their internal stratification to comprise forest units which suggest sequences of washover deposits. [ABSTRACT FROM AUTHOR]

Beach nourishment was applied at three fetch-restricted sites along the estuarine margin of Delaware Bay, New Jersey. Evaluation of geomorphological performance of the nourishment project was conducted through seasonal monitoring to track linear features (shoreline, dune crest, peat edge) and to create digital elevation models (DEMs). Comparisons of the DEMs yielded sediment budgets of the updrift, fill area, and downdrift zones as well as the spatial and temporal evolution of the tidal flat, beach, and dune features within the zones. Through four years, Moore's Beach lost all of the emplaced fill as well as an additional −5446 m3 from the fill area. The shoreline position shifted inland −12.78 m, and the foredune crest shifted inland −9.23 m. The fill area at Pierce's Point lost all of the fill and an additional −3810 m3. The shoreline and dune crest shifted inland −7.35 m and −1.17 m, respectively. The Reed's Beach study area benefited from beach fill updrift that more than offset the losses in the fill area, a net gain of 2107 m3. There was a major contrast in volumetric change between the updrift and downdrift portions. Sediment budget calculations established alongshore transport was an important factor in the fetch-restricted estuarine environment driving the variable geomorphological responses in the updrift, fill, and downdrift zones. [ABSTRACT FROM AUTHOR]

Tróia peninsula, located on the western coast of Portugal, is undergoing tourism development, including construction of a marina. The marina basin was created by dredging a coastal stretch on the northern terminus of the peninsula on the estuarine side, making available beach-quality sediment for nourishment. A study was carried out to identify potential applications and opportunities to place the dredged sand in a beneficial manner. Many variables were considered in the study design in incorporating pre-project beach profile surveys and sediment sampling. Beach-fill design and placement procedures were proposed according to the purpose and constraints of the particular site, while recognizing the implications of the nourishment in a regional sediment management context. Between October 2006 and March 2007, 286,000 m3 of sand was placed along four beach sectors with a total alongshore extent of 1,700 m in the vicinity of the new marina and the Tróia Roman Ruins archeological site. The emplacements included dune, beach berm, and beach face nourishment, providing restoration of beaches and dunes and also increased buffering capacity in an area of damage to cultural resources of the peninsula. A monitoring program was deployed to assess performance and impacts of the nourishment on adjacent areas, and to identify problems and their causes. The surveys of August 2007 indicate that a significant part of the emplaced sand had been mobilized alongshore promoting the spreading of the fill material to down-drift areas while inducing a general reduction in the beach face slope, and attaining a more natural beach profile. [ABSTRACT FROM AUTHOR]

Barrier islands provide a host of critical ecosystem services to heavily populated coastal regions of the world, yet they are quite vulnerable to ongoing sea level rise and a potential increase in the frequency and intensity of oceanic storms. These islands are being degraded at an alarming rate, in part because of anthropogenic attempts at stabilization. In this article, we outline a possible sustainability strategy that incorporates the natural degree of substrate instability on these sedimentary landscapes. We recommend placing the focus for managing barrier islands on maintaining ecosystem function and process development rather than emphasizing barrier islands as structural impediments to wave and storm energy. [ABSTRACT FROM AUTHOR]

Coastal overwash is one of the most important hazards affecting the coastal zone and therefore has been the focus of several studies related to the establishment of setback lines. However, studies of extreme overwash (EO) events along urban beaches backed by a seawall or structure are scarce, and reveal the difficulties associated with its assessment, measurement and validation. The Nazaré coastal urban area (located on the west coast of Portugal) is developed adjacent to an embayed reflective beach and is subject to frequent and localized inundation due to EO events capable of overtopping the protection seawall. The current work develops a methodological approach to simulate total water levels (TWL) and seawall overtopping occurrences in time and space, with the ultimate goal of identifying the factors that govern the extreme overwash regime. The method uses multi-decadal time series of site-specific wave and tide, and high-resolution topo-bathymetric data, and recreates the TWL time series for a 36-year period. The model is successfully validated against video imagery and maximum swash line data that provide information on the reach of the water levels measured during modal and extreme TWL conditions along the studied beach. This study establishes the importance of the interaction of the modal and extreme hydrodynamic processes with the beach and backshore morphology. The Nazaré embayment is in equilibrium with the alongshore-varying modal wave conditions, resulting in higher vulnerability of the most sheltered sector during extreme events. [ABSTRACT FROM AUTHOR]

Geoindicators are used to describe reference situations and measure changes and trends in physical environment over time. They provide a simplified form to communicate complex data and information, and constitute a facilitator mechanism in the dialog among stakeholders. In this work, a review on the use of geoindicators in sandy coastal environments is performed. It was found that, despite the obvious advantages in reporting the state of the coast using geoindicators, their generalized adoption seems to be stalled and is limited to a few management settings and particular projects. The existence of a myriad of coastal geoindicators, that frequently are poorly defined, is identified as the major difficulty in their widespread use. The present work aims to contribute towards the establishment of a common framework for coastal geoindicators, focusing on sandy coastal environments. The main objective of the compilation and definition of the indicators herein presented is to simplify and clarify their designations, and objectively present the measurement and reporting criteria aiming at a consensus-based approach. Sixteen coastal geoindicators are identified as relevant for the description of the state of beach, coastal dunes, and coastal barrier environments. This effort contributes to the adoption of coastal geoindicators as an effective communication tool leading to a more standardized report on the state of the coastal zone. [ABSTRACT FROM AUTHOR]

Silveira, T.M., Carapuço, A.M., Sousa, H., Taborda, R., Psuty, N.P., Andrade, C. and Freitas, C., 2013. Optimizing beach topographic field surveys: matching the effort with the objectives In any study design, the surveying approach should match the objectives, thereby limiting the effort to focus on the purpose of the inquiry. Often, in beach geomorphological research, study design is based on expert judgment, that does not assure the optimization of the field surveys. In this study, several dimensions of survey strategies were evaluated to compare the outcomes and uncertainties associated with field data collection. The objective of this work is to assess the accuracy of the derived volumes achieved by different survey strategies, including cross- and alongshore lines, with varying density and spatial distribution, to optimize the field survey effort. A number of survey strategies are simulated, covering a range of data resolutions and configurations, replicating a number of possibilities for field data gathering. Topographical data from different field surveying approaches were analyzed for a 4 km long coastal stretch in Portugal. Measures of beach volume were computed from cross-shore as well as alongshore information, and the errors associated with each approach evaluated. Results show that beach volume varies with the adopted survey strategy. As an example, beach volume change can be adequately portrayed and survey effort minimized either through the surveying of 3 alongshore lines, or through 200 m spacing beach profiling. This work highlights the importance of the study design in beach contexts because of its inevitable influence on the results of volumetric change analyses. [ABSTRACT FROM AUTHOR]

Spatial variations in sedimentation during individual tidal cycles were investigated using filter paper traps. The mean mass of sediment deposited in each tidal cycle was higher at the levee edge than at the inner marsh. The mass of sediment decreased with distance from the head of the estuary. There were weak relationships between tidal regime and sediment accumulation. Spatial variations of annual accretion rates were investigated with marker plots. The annual accretion rate at the inner marsh was higher (1.5 to 3.5 cm/y) than that at the tidal river levee edge (0.8 to 3.0 cm/y). Total suspended sediment (TSS) concentrations in the tidal water column indicated that the accretion rate was affected by vegetation. TSS concentrations in the water column leaving the vegetation cover during ebb tidal flows dramatically decreased. There were strong relationships between the concentration of suspended load and accretion rate. The spatial pattern of sedimentation processes at different timescales was mostly due to erosion of the levee edge by tidal flow. The major findings are: (1) The spatial patterns of sedimentation processes at various timescales are different, (2) vertical accretion rates ranged from 0.9 cm/y to 3.5 cm/y, (3) the study area has a depositional regime over the timescale of the present data, (4) the mean and minimum deposition rates in the study area are higher than other cited systems, and (5) the high accretion rate of this area is related to human-induced environmental change, and the sedimentation trajectory is now evolving to a new equilibrium. [ABSTRACT FROM AUTHOR]