Long-Term Evolution of the Guadeloupean Shoreline (1950–2017)
Résumé
Insular environments have long been recognized as sensitive to issues linked to natural forces that occur every day (swells, currents, and winds) or that are exceptional (storms and cyclones). However, over the past few decades, additional pressure has arisen throughout many already-fragile islands: anthropization, the modification of natural areas by humans and for human usage. Since the 1970s, the number of tourists visiting Guadeloupe Island has strongly increased, driving coastline modifications (building of houses, hotels, diving clubs, etc.). Using panchromatic and high-resolution aerial imagery, the evolution of the coastline from 1950 to 2017 of 19 Guadeloupean beaches was assessed. This evolution was compared with a coastal vulnerability index to determine the sensitivity to morphological, hydrodynamic, and anthropic factors of each studied beach. The results showed that the Guadeloupe coast has become increasingly urbanized since the 1950s, with a transition from 4% of manmade structures along the shoreline in 1950 to 18% in 2017 across the study sites. Across all beaches, coastal erosion was noted and was caused by the simultaneous action of natural factors (hydrodynamics, storms, etc.) or anthropogenic factors (mass tourism, economic development, etc.). Overall, this study highlights the issue of coastal artificialization in Guadeloupe. To avoid irreversible detrimental effects of coastal degradation on the local population and the country's economy, new decisions favoring natural coastal environment buffers must be made rapidly.