Orla marítima em regiões de grande especulação imobiliária no extremo sul da Bahia

caracterização de mudanças no uso de solo e mapeamento de acessos públicos às praias.

Abstract

This study focused on the waterfront of the neighborhoods of Arraial d’ Ajuda, Trancoso and Caraíva, located in the municipality of Porto Seguro, Bahia. Three objectives were set: 1 - To assess the variation of vegetation cover on the seafront of the aforementioned districts between the years 2017 and 2020; 2 - Map public access to the region's beaches and 3 - Generate subsidies for integrated coastal management based on an ecosystem perspective. Based on Sentinel satellite images (2017 and 2020), vegetation cover was evaluated by the NDVI index. In the district of Arraial d'Ajuda, the NDVI ranged from -0.44 to 0.83, with a median equal to 0.57 in 2017, in 2020 it ranged from -0.57 to 0.79, with a median equal to 0, 47. In Trancoso, it ranged from -0.28 to 0.82 in 2017, with a median equal to 0.63, while in 2020 the NDVI ranged from -0.21 to 0.78, with a median equal to 0.54. In Caraíva it ranged from -0.42 to 0.82 with a median equal to 0.57 in 2017 and in 2020 it ranged from -0.34 to 0.78 with a median equal to 0.47. The NDVI values ​​of each pixel were extracted to perform a temporal analysis where significant differences were evidenced in the comparison between the years 2017 and 2020, in the neighborhoods of Arraial d'Ajuda (Kruskal-Wallis: X2 = 3936.6; p< 00 .1), Trancoso (Kruskal-Wallis: X2 = 6408.3;p<0.01) and Caraíva (Kruskal-Wallis: X2 = 9707.8;p<0.01). This result suggests that there was a loss of plant biomass throughout the analyzed period in all the studied districts. The mapping of public accesses to the beaches was carried out with the use of GPS, in three field trips (10/30/2020, 02/24/2021 and 09/01/2021). Nine public access points were identified in 14.8 kilometers of the coast of Trancoso, 11 points of public access in 12.1 kilometers of the coast of Arraial and 23 points in the 29.5 kilometers of coast of Caraíva. It was observed that most of the coastline of the studied districts is dominated by private developments, which limits access to beaches, mainly in Trancoso and Arraial d'Ajuda.