Assessing the impact of coastal flooding along the northern Yucatan Peninsula associated to sea level rise under different shared socio-economic pathways

Abstract

Sea level rise (SLR) inundation threats were evaluated across four barrier island coastal socio-ecosystems in the northwestern Yucatan Peninsula. Firstly, a 2-D hydrodynamic model was implemented, using a high-spatial-resolution LIDAR Digital Elevation Model, and was forced with SLR projections (17th- 83rd percentiles) for the year 2100 under three Shared Socio-economic Pathways (SSP) (SSP1-2.6, SSP2-4.5, and SSP5-8.5) along with the local micro tide. Model results suggest important impacts in these coastal communities, particularly under the worst-case flood scenario (SSP5-8.5 83rd percentile; spring high tide), projecting flooding in 22–64% of city blocks of those towns by 2100. Moreover, rapid population growth over the past ten years has further increased flood risks. Further analysis focusing on Progreso, the largest coastal town in the study region, flood, population, and land use cover maps were overlaid to exhibit exposed elements to floods. This analysis reveals that large portions of forests (43.45%), shrublands (32.35%), grasslands (21.68%), and artificial surfaces (2.51%), and numerous city blocks in the lee side of the barrier island could be flooded under this worst-case flood scenario. Secondly, different alternatives to reduce the exposure to coastal flooding (levees, inhabitant’s relocation, land elevation build-up, and stilt houses) are discussed. This methodology can be useful to decision-makers for prevention, preparedness, mitigation of SLR impacts, and updating land use in northern Yucatan and other similar coastal regions.