Global climate change: an opportunity for coastal dunes??

Abstract

The predictions for coastal change under the scenario of global sea-level rise offer impending disaster for the variety of coastal morphologies, their associated habitats, and the accompanying infrastructure. However, the predictions tend to ignore the role of sediment budget in the maintenance of coastal morphology and the dynamics of sediment transfers in the beach-dune sand-sharing system. Accepting that shoreline displacement may be an outcome of sea-level rise and a negative sediment budget, conditions are presented that could lead to a positive or equilibrium sediment budget in the coastal foredune and the retention of the foredune system even as it is being displaced. Accommodation space is a key requirement for the continued functioning of the foredune morphologies during periods of sea-level rise.

Environmental Impacts—Coastal Ecosystems

“…Other more realistic rule-based approaches for predicting shoreline change have been provided by Ranasinghe et al (2012) and Rosati et al (2013), but these have not yet been tested on North Sea sandy shores. Beach profile adjustments to accelerated SLR are more likely to involve significant alongshore components and variations as well as greater sensitivities to local changes in sediment budgets (Psuty and Silveira 2010). Even though projections of the North Sea wave climate suggest no to minor change, it is possible that accelerated SLR and changes in wave direction may still aggravate coastal erosion.…”

“…The precise response of the nearshore zone to climatic change and its consequent impact on adjacent coastal dunes is therefore ambiguous and probably subject to substantial regional variation, as in some areas the hydrodynamic boundary conditions may not change very much, while in other areas the coastal sediment budget system will be undergoing complex adjustments. Paradoxically, while sandy beaches in the worst case may get narrower and squeezed between human pressure and accelerated SLR (Carter 1991;Schlacher et al 2007), the remobilisation and increased dynamics in sediment exchange across the nearshore profile as it is adjusting to SLR may in fact yield an opportunity for reinvigorating coastal dune development (Psuty and Silveira 2010), as illustrated in Fig. 9.2.…”

Low-Cost UAV for High-Resolution and Large-Scale Coastal Dune Change Monitoring Using Photogrammetry

“…After the onset of sediment deficit in most coastal areas in the mid-20th century, many observations highlighted that coastal dunes buffer storm waves and greatly enhance beach resilience (e.g., reference [24]). In the context of Climate Change (sea level rise, increase in storminess) and increasing anthropogenic pressure, dunes are therefore more than ever a critical component to the future of our coasts [25,26]. Vegetated coastal dunes also host leisure activities and provide outstanding ecosystem values and services such as nest or incubation sites, filtering of pollutants and ecological niches for plants that are adapted to dynamic conditions [27].…”

Geomorphology and sedimentology of Porto Pino, SW Sardinia, western Mediterranean

“…More recent studies conducted about these co-dependent systems reveal that they often have correlated morphodynamics with strongly coupled sedimentary fluxes (e.g. Peterson et al, 2010;Psuty & Silveira, 2010;Sherman & Bauer, 1993;Short & Hesp, 1982). De Muro and De Falco (2015) described some of the natural processes affecting coastal systems in Sardinia, highlighting the interaction between beach and dune systems.…”