Impact of Relative Sea-Level Rise on Low-Lying Coastal Areas of Catalonia, NW Mediterranean, Spain

Uxía López-Dóriga,José A Jiménez

doi:10.3390/w12113252

Abstract

Low-lying coastal areas are high-risk areas regarding sea-level rise (SLR) due to the combination of low elevation, subsidence and currently low sediment supply, on the one hand, and their high natural and socio-economic values, on the other. Because of this, there is a growing need to assess the integrated impact of SLR taking into account the interactions between physical and ecological factors to make more informed decisions for the design of adaptation strategies. This study presents a methodology for improved SLR-induced flood-damage assessments in natural areas which is composed of (i) a pseudo-dynamic method coupling equilibrium-based coastal response and classical bathtub modeling approaches and (ii) a simple method to account for habitat conversion following inundation. This methodology is applied to low-lying coastal areas of Catalonia under different SLR scenarios, which show very different sensitivities depending on the configuration of the water-land border, topography, geomorphology, and degree of human impact on the floodplain. In terms of potential impact, natural habitats will be the most benefited from the likely conversion at the expense of agriculture lands. This can help coastal managers to adopt adaptation strategies where considering the inherent capacity of some coastal landscapes to adapt opens up new alternatives.

Highlights

Sea-level rise (SLR) will significantly alter coastal landscapes through inundation, erosion and salt-water intrusion of low-lying areas worldwide
By 2100, the protection provided by the morphodynamic coastal response decreases, with the inundated area being just 11.3%, 5.1%, and 2% lower than that calculated by using the passive bathtub approach for RCP4.5, RCP8.5, and H+
The inclusion of the capacity for active sandy shorelines to respond dynamically to SLR yielded a smaller inundation extent relative to a passive inundation approach, and this effect was most pronounced under the low-medium RSLR scenarios

Summary

Introduction

Sea-level rise (SLR) will significantly alter coastal landscapes through inundation, erosion and salt-water intrusion of low-lying areas worldwide. SLR coupled with subsidence rates (called relative sea-level rise (RSLR)) will increase the vulnerability of coastal communities and economic sectors to flooding in the near future, causing both environmental and socioeconomic changes [5,6]. Within this context, the Mediterranean coast is especially vulnerable to the impact of RSLR due to the high concentration of sensitive low-lying areas, anthropogenic pressures, and natural hazards [7,8,9]. There exist a large number of risk assessments to RSLR for low-lying environments in this region, such as for the Po delta and other Italian plains [11,12,13], the French Mediterranean coastline [14], and the Egyptian coast [15] among others

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