Banca de QUALIFICAÇÃO: FILIPE EZEQUIEL DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : FILIPE EZEQUIEL DA SILVA
DATA : 12/07/2018
HORA: 09:00
LOCAL: Sala 1 - PPGG
TÍTULO:

The sedimentary dynamics of the Northeastern littoral through Remote Sensing products

PALAVRAS-CHAVES:

Coastal processes; sedimentary dynamics; remote sensing; Landsat

PÁGINAS: 55
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

The northern littoral Rio Grande do Norte State (RN), Brazil, is a region where the intense coastal dynamics favors the continuous mobility, destruction and emergence of mesotidal sandy barriers (MSB), tidal inlets and active dunes (AD). Considering the short time that these changes occur, this paper aims to describe how the sedimentary dynamics of this region happens through remote sensing products and multitemporal analyzes. Thus, we used Landsat 5 TM and Landsat 8 OLI sensors images to produce time-lapses and mapping of geomorphological features. In addition, we tested an automatic method based on the unsupervised Iso Cluster classification as an alternative way to obtaining data from these features. This new method proved to be very effective, presenting a 91% correlation with the conventional mapping method. About the evolution of geomorphological features, we observed that depending on the time scale used, the results could vary considerably. In addition, MSB presents a complex evolution marked by continuous, and intercalated, accretion and erosion cycles. Over a period of 1 year, variations in MSB areas can reach 3 km² along a 50 km stretch of coast. The ephemerality of some features is remarkable such in the case of the Fernandez-Tubarão Islands system only 5% of all areas already occupied by these MSB remained unmodified during 32 years of analysis. In that same period the Fernandez’s sandy spit migrated 3.6 km towards the E-W. Another important aspect we noticed concerns some MSB act as sediment stocks for the dunes. In relation to the dunes, we verified that 3 of the 5 dune fields no longer have direct connections with the beach zone, which makes it difficult the feeding by sandy sediments. The dune fields separated from the beach zone present large wind deflation areas in their proximal portions. In the case of Diogo Lopes AD, the deflation surfaces are covered by lag deposits, which are composed of rizoliths, freshwater gastropod shells, clusters of varied marine mollusks shells from archaeological origin as well other archaeological artifacts. The evidence set indicates that the dunes currently without direct connection with the beach zone are destined to disappear.

MEMBROS DA BANCA:
Externo à Instituição - ANDRE GISKARD AQUINO DA SILVA - UFRN
Presidente - 2218779 - HELENICE VITAL
Interno - 2042405 - MOAB PRAXEDES GOMES