Regional scenarios of sea level rise and impacts on Basque (Bay of Biscay) coastal habitats, throughout the 21st century

Flood-risk mapping for sea-level rise and extreme wave events using bathymetric and topographic lidar within the basque coast

“…An analysis of sea level records from the tide gauge of Santander, located in the SE Bay of Biscay, has revealed that relative mean sea-level has been rising at a rate of 2.08 ± 0.33 m m yr-1, from 1943 to 2004 (Chust et al, 2009); this is consistent with sea-level trends from other tide-gauge measurements within the area and with previous results obtained in the Bay of Biscay (Marcos et al, 2005). The mean sea level in the bay is expected to rise between 29 and 49 cm from 2001 to 2099, as estimated from Atmosphere-Ocean Coupled General Climate Models (AOGCMs) outputs as a result of regional thermal expansion and global ice-melting (Chust et al, 2010). The objective of this contribution is to assess the impacts of the future projected SLR and extreme wave events on Basque coastal habitats (saltmarshes, sandy beaches and dunes, estuaries and urban areas) by generating flood risk maps within the Gipuzkoan coast and the Oka estuary (Basque coast, northern Spain, south-eastern Bay of Biscay.…”

“…This map indicates that 164.1 ha are identified as vulnerable to extreme waves. The relative effects by habitats are shown in Table 1 and compared with the effects of the sea level rise obtained by Chust et al (2010). The effect of the extreme wave run-up will affect especially within the coastline (mainly affecting sandy and shingle beaches, dunes, artificial land and supralittoral rock); whilst the effect of sea level rise will be concentrated over low-lying areas within the inner estuaries, with terrestrial, wetlands and salt-marshes and artificial habitats being the most affected.…”

“…The computed flood level of extreme waves expected for a 50-yr return period was compared with the scenario of mean sea level rise expected by the end of the 21 st Century (i.e. 49 cm; Chust et al, 2010). The increase of extreme Hs by 2050 is 3 cm according to Universidad de Cantabria (2007), hence, it is negligible compared with the mean extreme wave along the coast (8.17 m).…”

“…The Digital Elevation Model (DEM) of Gipuzkoa (available from http://b5m.gipuzkoa.net/web5000/) was extracted using airborne topographic LiDAR (Chust et al, 2010). It has a vertical accuracy of 0.15 m RMS, in low vegetated and low slope areas, and 1 m x 1 m spatial resolution.…”

Sustainable floodplain management for flood prevention and water quality improvement

“…However, other estimates of multi-decadal global rises indicate slightly lower rates (1.5 ± 0.4 mm year -1 ) occurred between 1961 and 2003 (Domingues et al 2008). According to Chust et al (2010), global climate models predict a mean sea level rise of between 0.18 and 0.59 m by the end of the twenty-first century, with high regional variability. The two major causes of global sea level rise are thermal expansion of the waters of the oceans and the loss of land-based ice due to increased melting, both processes being driven by global warming (Bindoff et al 2007;Chust et al 2010).…”