Shoreline Change and Coastal Erosion: An Analysis of Long and Short-Term Alterations and Mitigation Strategies on the Coast of Icapuí, Northeast Brazil

Sandy beaches play a crucial role as natural barriers against climate change and hold significant socioeconomic value. In the municipality of Icapuí, on the eastern coast of Ceará, erosion has affected some of its beaches since the 2000s, impacting structures near the Shoreline (SL), such as schools, inns, and residences. This article analyzed the SL dynamics on the beaches of Barreiras de Baixo, Barreiras de Cima, and Barrinha, located in the mentioned municipality, using two scales of analysis: in the short term, with in situ surveys using geodetic receivers between 2015 and 2023, and in the long term, with orbital images from 2002 to 2024. For statistical analysis, the End Point Rate (EPR) and Linear Regression Rate (LRR) methods were applied in ArcGIS software using the Digital Shoreline Analysis System (DSAS) version 5.1 extension. The short-term analysis revealed an average EPR of 0.0 m/year, with a maximum progradation of 7.1 m/year and maximum erosion of 6.4 m/year. The LRR showed an average of -0.2 m/year, with a maximum progradation of 7 m/year and maximum erosion of 6.7 m/year. The long-term analysis showed an average EPR of -1.1 m/year, with a maximum progradation of 0.5 m/year and a minimum erosion of 3.9 m/year, while the LRR indicated an average of -0.7 m/year, with maximum erosion of 3.6 m/year and maximum progradation of 1.6 m/year. These results indicate a more pronounced retreat of the SL over time. The analysis also revealed that containment structures, such as Rip-rap, have replaced wooden stakes and sandbags previously used by local communities, stabilizing 63.2% of the SL. The forecasts obtained through this study for the years 2034 and 2044 indicate shoreline retreat in areas still without protection, highlighting the urgent need for effective participatory planning. It is essential to align this planning with the Municipal Climate Change Adaptation Plan and the Integrated Coastal Management Plan (ICMP). Maintaining protection structures and conducting continuous monitoring is crucial to adapting coastal management strategies, protecting vulnerable communities and ecosystems.