Stabilization at Santinho-Ingleses dunefield, Southern Brazil: What will be the future of sediment input to Ingleses Beach?

Abstract

This paper describes the overpassing process using a case study from southern Brazil, that present a decadal pulse of sediment entering in the system. A transgressive dune field extends across a headland from Santinho beach to Ingleses beach. Analysis of precipitation data (1961-2014), wind direction and speed (1964-2014), aeolian drift potential (DP), aerial photographs/satellite images (between 1938 and 2016) and morphological data (2002, 2010 and 2014) make it possible to analyze the decadal-scale dune field evolution. The wind historical data showed southern wind as the stronger, moving the dune crests to north. The rainfall analysis presents an increasing trend leading to a decrease in drift potential and favors dune stabilization by vegetation growth. There is a decadal pulse of sediment inputs to the system, as well. The northern sector of Santinho beach has a positive budget and provides about 6,000m³/year of sediment to the foredune. Then, with southern winds, the sediment migrates into the dune field (about 3,000-5,000m³/year) reaches Ingleses by overpassing, ensuring a positive sediment budget for the system that occurs at east side of the Ingleses beach.