Boulevard Park shoreline improvements project:environmental impact assessment

The purpose of the Boulevard Park Shoreline Improvements Project is to remove fill, riprap, and sod from the shoreline along Boulevard Park and replace this hardened shoreline with sloping gravel, sand beaches, and rock groins. Ultimately, this alteration of the shoreline will hinder erosion, improve habitat, improve public access to the bay, and decrease the impact of storm surges

Historical shoreline response to inlet modifications and sea level rise (M.S. Engineering Thesis)

This thesis examines the historical shoreline response to inlet modifications and sea level rise. Inlet modifications are considered to be the geographic stabilization and training (through the use of structures) of natural inlets and the creation and further modification of artificial inlets. Shoreline response to natural and artificial processes must be understood in order to predict the performance of the coastline. The tendency for creating and modifying inlets increases as industry and population growth demands. Sea level rise is a natural process which cannot be controlled at this time. Current theoretical approaches to predicting shoreline response indicate that sea level rise and inlet modifications can cause substantial shoreline impact. Florida, with roughly a century of shoreline position and relative sea level data, provides a basis for examining past trends and comparing them with theory. The shoreline of Florida was found to be accreting with the greatest accretion along the east coast. Shoreline responses within the boundaries of the erosional influence of inlets due to their creation and/or modification were examined for 19 inlets around the coast of Florida. The differences in the shoreline response before and after the initial modification of each inlet show the erosional strain that inlets apply on the nearby shoreline. The effect on shoreline response due to the human intervention (unnatural processes) of modifying inlets was isolated and examined. The shoreline response due to this "human intervention" was erosional, thereby showing the negative impact that modified inlets have on shorelines. This induced erosion is responsible for the loss of roughly 21.6 million cubic yards of sand from the shoreline that is within the erosional influence of Florida's east coast inlets. Combining the shoreline changes due only to natural processes with sea level rise data allows for comparison with the commonly accepted Bruun Rule for shoreline response as a result of a changing sea level. This comparison and the effects of including a lag time between a rise in sea level and a change in shoreline along the east coast of Florida during the last century show no agreement with the Bruun Rule and no correlation with a specific lag time. (153 pp.

Morphological changes, beach inundation and overwash caused by an extreme storm on a low-lying embayed beach bounded by a dune system (NW Mediterranean)

The geomorphological evolution of a low-lying, micro-tidal sandy beach in the western Mediterranean, Pals beach, was characterized using airborne Light Detection and Ranging (LiDAR) data. Data were collected in prior to and six months after the impact of an extreme storm with a return period of approx. 50 years, with the aim of characterizing the beach's response to the storm. The use of repeated high-resolution topographic data to quantify beach geomorphic changes has allowed assessment of the accuracy of different proxies for estimating beach volume changes. Results revealed that changes in the shoreline position cannot accurately reproduce beach volume changes on low-lying beaches where overwash processes are significant. Observations also suggested that volume estimations from beach profiles do not accurately represent subaerial volume changes at large profile distances on beaches with significant alongshore geomorphological variability. Accordingly, the segmentation of the beach into regularly spaced bins is proposed to assess alongshore variations in the beach volume with the accuracy of the topographic data. The morphological evolution of Pals beach during the study period showed a net shoreline retreat (- 4 m) and a significant sediment gain on the subaerial beach (+ 7.5 m3/m). The net gain of sediment is mostly due to the impact of the extreme storm, driving significant overwash processes that transport sediment landwards, increasing volume on the backshore and dunes. The increase of volume on the foreshore and the presence of cuspate morphologies along the shoreline also evidence post-storm beach recovery. Observed morphological changes exhibit a high variability along the beach related to variations in beach morphology. Changes in the morphology and migration of megacusps result in a high variability in the shoreline position and foreshore volume changes. On the other hand, larger morphological changes on the backshore and larger inundation distances occur when the beach and the dunes are lower, favouring the dominance of overwash. The observed storm-induced morphological changes differ from predicted beach storm impacts because of spatial and temporal variations in the beach morphology, suggesting that detailed morphological parameters and indicators used for predicting beach vulnerability to storms should be regularly updated in order to represent the pre-storm beach conditions. Finally, observed morphological changes in Pals Bay evidenced a different behaviour between natural and urban areas, with better post-storm beach recovery on natural areas where the beach is not artificially narrowed.Peer ReviewedPostprint (author's final draft

What Drives Property Owners to Modify their Shorelines? A Case Study of Gloucester County, Virginia

This analysis uses data from a survey of shoreline property owners combined with data on shoreline modification permits to examine whether and how property owners modify their estuarine shorelines. We find that shoreline armoring is very popular among property owners that choose to modify their shoreline. While living shorelines are less common, applications for them are increasing both in absolute numbers and as a percentage of all shoreline modification requests. A number of different issues factor into the shoreline modification decision including effectiveness, cost, aesthetics, and property values. More valuable parcels are more likely to be modified, as are parcels that have been owned longer. Parcels with a high percentage of natural cover or agricultural use are less likely to be modified. Parcels with primary structures that are closer to the shoreline are more likely to have some sort of armoring. Regardless of their choice of shoreline modification, almost all survey respondents believe that their choices have had a neutral or positive impact on erosion and the health of the Chesapeake Bay

Deep uncertainties in shoreline change projections: an extra-probabilistic approach applied to sandy beaches

ABSTRACT:Global mean sea level rise and its acceleration are projected to aggravate coastal erosion over the 21st century, which constitutes a major challenge for coastal adaptation. Projections of shoreline retreat are highly uncertain, however, namely due to deeply uncertain mean sea level projections and the absence of consensus on a coastal impact model. An improved understanding and a better quantification of these sources of deep uncertainty are hence required to improve coastal risk management and inform adaptation decisions. In this work we present and apply a new extraprobabilistic framework to develop shoreline change projections of sandy coasts that allows consideration of intrinsic (or aleatory) and knowledge-based (or epistemic) uncertainties exhaustively and transparently. This framework builds upon an empirical shoreline change model to which we ascribe possibility functions to represent deeply uncertain variables. The model is applied to two local sites in Aquitaine (France) and Castellón (Spain). First, we validate the framework against historical shoreline observations and then develop shoreline change projections that account for possible (although unlikely) low-end and high-end mean sea level scenarios. Our high-end projections show for instance that shoreline retreats of up to 200m in Aquitaine and 130m in Castellón are plausible by 2100, while low-end projections revealed that 58 and 37m modest shoreline retreats, respectively, are also plausible. Such extended intervals of possible future shoreline changes reflect an ambiguity in the probabilistic description of shoreline change projections, which could be substantially reduced by better constraining sea level rise (SLR) projections and improving coastal impact models. We found for instance that if mean sea level by 2100 does not exceed 1m, the ambiguity can be reduced by more than 50%. This could be achieved through an ambitious climate mitigation policy and improved knowledge on ice sheets.This research has been supported by the BRGM, IHCantabria and the ERA4CS-ECLISEA project (grant no. 690462)

Capacity-building activities related to climate change vulnerability and adaptation assessment and economic valuation for Fiji

The Terms of Reference for this work specified three objectives to the Fiji component: Objective 1a: to provide a prototype FIJICLIM model (covered under PICCAP funding) Objective 1b: to provide training and transfer of FIJICLIM Objective 1c: to present and evaluate World Bank study findings and to identify future directions for development and use of FIJICLIM (2-day workshop) Proceedings of the training course and workshop were prepared by the Fiji Department of Environment. The summaries from these proceedings reflect a very high degree of success with the contracted activities

Impacts of sea-level rise-induced erosion on the Catalan coast

The final publication is available at Springer via http://dx.doi.org/10.1007/s10113-016-1052-xThe Catalan coast as most of the developed Mediterranean coastal zone is characterized by the coincidence of stresses and pressures on the natural system with a high exposure and low adaptive capacity. Due to this, climate change-induced effects will increase natural hazards and aggravate their associated impacts and, in consequence, it is necessary to assess their effects for proper long-term management. In this work, we assess the impact of sea-level rise (SLR)-induced shoreline retreat on the Catalan coast for three scenarios ranging from 0.53 to 1.75 m by the year 2100. Implications are analysed in terms of affectation of two main functions provided by beaches, i.e. recreation and protection. Obtained results show that CC will be a serious threat to analysed functions since the expected enhanced shoreline retreat will severely decrease the recreational carrying capacity and the capacity of protection in the near future under tested scenarios. The actual level of development along the coastal zone reduces the natural resilient capacity of beaches to SLR in such a way that the lack of accommodation space can be identified as a main factor for the estimated impacts.Peer ReviewedPostprint (author's final draft