Dinâmica das praias (Artistas e Atalaia) e da linha de costa contíguas à desembocadura do Rio Sergipe, Aracaju, Sergipe

• Autor(a) principal: Jesus, Luciana Vieira de
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/5398
• topic: Geociências; Rio Sergipe; Erosão; Sedimentos (Geologia); Proteção da costa; Proteção ambiental; Sedimentos; Taxas de recuo; Faixas de proteção; Erosion; Retreat rates; Setbacks; Sediments; CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS

The Artistas and Atalaia beaches, located in Aracaju, Sergipe, are subject to coastal processes (waves, currents and winds) and Sergipe river mouth dynamics. At these beaches, from 2007 to 2008, severe erosive events resulted in the destruction of several anthropogenic structures (Praça de Eventos, bars/restaurants, etc.). These erosive events motivated the elaboration of this dissertation, whose the aim was to analyze these beaches morphology and its Sergipe river mouth coastline dynamics, in Aracaju. The methodology consisted of: (i) beach profile and sediments volume analysis (2008-2015); (ii) high tide shoreline (HTS) multi-temporal analysis (2009-2015) using satellite images; (iii) HTS change rate calculation; (iv) setbacks determination; and (v) textural and compositional sediments analysis. The beaches had great morphological variability, alternating between erosive and depositional processes, especially erosion on the Artistas’ beach and deposition on the Atalaia’s beach. The HTS in all profiles also varied significantly; it did not follow a linear trend of advance and/or retreat. In the investigated period (2008-2015), erosion prevailed in the 1, 2, 3 and 6 profiles (-320, -150, -3.5 and -130 m³/m, respectively) and HTS retreated, while in the 4 and 5 profiles prevailed depositional processes (+162 and +485 m³/m, respectively) and the HTS advanced. The HTS retreat rate , ranging from 0.5 to 13 m/year, allowed the establishment of two setbacks: 360 m for “lightweight” construction and 730 m for “heavy” constructions. Moreover, the investigated beaches sediments are mainly medium sand-sized particles, moderately sorted, and composed of quartz. The content of heavy minerals in sediments is low and represented mainly of ilmenite, zircon and rutile. These beaches and sediments characteristics are critical on beaches recovery projects of artificial feeding. Thus, this work offers subsidies for urban and environmental planning of the study area.