Shoreline change of the Mucuripe harbour zones (Fortaleza-Ceará, Northeast of Brazil) 1972 - 2003

Abstract

This study analyses the space-time evolution along the Fortaleza coast over the past 31 years (1972-2003) with a special emphasis on the Mucuripe port area (Fortaleza, Ceará, Brazil) examining changes in the coastal dynamics produced by the building of the city’s port. The construction of the port’s jetty interrupted the natural feeding process of the beaches with sediment moving east to west. Sediment was blocked east of this structure leading to an erosion process to the west. This multi-temporal study is based on the analysis of aerial photographs and images from the Quickbird satellite. The objective is to determine the recent evolution of this coastline through calculation of the variation in retrograding and prograding areas. The variation of the city of Fortaleza's dunebeach interface shoreline, which concerns an extension of approximately 30 km of shoreline, revealed a prograding rate of 0.8284 km2 /31 years (1972/2003) and a retrograding rate of 0.0701 km2 /31 years (1972/2003). Analysis of images of Mansa Beach, located in the Mucuripe port basin, showed that in 1972 Mansa Beach had an area of 0.13843 km2, in 1998 it increased to 0.15307 km2 and in 2003 it reached 0.15455 km2. The analysis revealed that the changes in the shoreline are more subject to shoreline accretion. The analysed period shows a 92% a ccretion rate and an 8% erosion rate. The results contribute to the improved management of the Fortaleza coast.