Evolução da ocupação dos campos de dunas de Fortaleza -Ceará: causas e consequências para a cidade

Abstract

Dunes are described as eolian reliefs with large sediment availability, which can present a variety of shapes, by having the wind action as the main determinant force. Despite their proven relevance, dune ecosystems are suffering environmental stresses due to urban sprawl, mining, pollution, also recreational and tourist activities that modify the sediment transport, thus, changing the local sediment balance. In the coastal city of Fortaleza, where 72% of its area is built-up, and the understanding about which are the main urban expansion activities responsible for decharacterizing the original dune cover and its respective ecosystem services, is a great key for designing mitigation strategies for the damage over the city. In this study, bibliographical surveys were conducted and remote sensing analyses were applied by comparing three sectors with a large group of dunes at different time intervals (1975, 2003, 2010 and 2020). Dunes of the first sector, located in Barra do Ceará, lost 98.51% of their original covering in 1975, the dunes of sector 2, located in Praia do Futuro and surroundings area, lost 72.54%, and sector 3, located in Sabiaguaba, had the lowest percent of loss for characterization of the dunes, with 36.81% of the dunes area lost. The main activity resulting from urban expansion that may have helped in decharacterizing of the dunes was the residential area, and then the commercial activities. The high level of decharacterization of dunes in coastal cities, resulting from the disorganization of the public management over the urban occupation process, may impact the ecosystemic services provided to the city, such as climate regulation, recreation, and coast protection against climate events.