EROSÃO COSTEIRA E FAIXAS DE RECUO EM PRAIAS ARENOSAS DO SUL DE SERGIPE, BRASIL

Coastal erosion and setback lines on southern Sergipe sandy beaches, Brazil

Abstract

The aims of this paper were to analyze the historical shoreline changes and to verify the efficiency of setback lines on estuarine and oceanic sandy beaches located on south Sergipe, northeastern Brazil. The methodology consisted in determining the rate of change and the behavior of shoreline (1971 to 2017), and in analyzing the efficiency of the use of setback lines for light and heavy buildings if they had been implemented in 1971. The estuarine and ocean beaches presented respectively -5.6 and -1.6 m/year average erosive rates. The shoreline erosive behavior occurred in 82.4 % of the estuarine beach and in 38.6 % of the ocean beaches. The setback lines efficiency analysis for heavy building showed that if they had been implemented in 1971, many of the damage to anthropic structures would have been avoided. However, the methodology adopted is inadequate, as it does not consider the time period (short, medium, or long-term). The use of the erosive rate verified in each location multiplied by the desired time seems to be the most viable alternative in the absence of other data. This study demonstrates that a simple method can be used successfully.

Key words: shoreline, historical changes, rate of change, efficiency analysis.