Banca de DEFESA: DANIELE VASCONCELOS DO NASCIMENTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : DANIELE VASCONCELOS DO NASCIMENTO
DATA : 31/10/2017
HORA: 14:00
LOCAL: Instituto de Geociências
TÍTULO:

SPACE-TEMPORAL EVALUATION AND GEOCHEMICAL CHARACTERIZATION OF APICUNS IN THE BAY OF ALL SANTOS, BAHI

GEOCHEMICAL CHARACTERIZATION OF APICUNS IN THE BAY OF TODOS OS SANTOS, BAHIA, BRAZIL

PALAVRAS-CHAVES:

supratidal saltflats, geotechnologies, temporal studies, geochemistry, trace metals

PÁGINAS: 78
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
SUBÁREA: Geologia
ESPECIALIDADE: Geoquímica
RESUMO:

The objective of the present study was to evaluate the space and temporal variability (1954 - 2015) and geochemistry analysis of saltflats located on the cities of Jaguripe (JP), Madre de Deus (MD), Saubara (SB) and Vera Cruz (VC), in Todos os Santos Bay (BTS). Saltflats are flat areas with high salinity, present in the supra-tide region that devoid of vegetation or with shallow vegetation; they are always associated with mangroves and can be found in intertropical regions around the world. At BTS mangroves and saltflats occupy, respectively, 177.6 km² and 10.2 km². This research was split in two steps: (1) multitemporal study of the saltflats through the application of geotechnologies, consisting in areal photographs and/or satellite imagery overlapping on different years (1954, 1989, 2010 and 2015), and (2) geochemical analysis through analysis of 49 sediment samples collected at different depths in three points transect. Each transect was defined in a apicun at each city, so there were four at total. The sediment analysis were: salinity, pH, Total Organic Carbon (COT), Nitrogen (N), Sulfur (S), assimlable phosphorus (P), granulometry, chemical elements (Al, Ca, Cd, Cu, Fe, K, Na, Ni, Mg, Mn, Zn). In the spacial and temporal evolution there was a predominant reducing saltflats area as a result from them being taken over by mangroves, as well as urban development and landfills. This area variability can be related to variability in the sea level considering its elevation at the last decades. However, this study shows that, at the same bay, different locations can present a variable evolutionary spacial behavior of the saltflats. Geochemically speaking, the saltflats have little difference. Even though they are predominantly sandy (at an average of 80% of sand considering all saltflats), the granulometry varies, with finer grains at the BTS’ nothern region (MD, SB) in contrast to coarser granulometry close to the bay’s entry (JP and VC). The phisical and chemical parameters and metal concentration also vary among the saltflats, as well as they present internal variability, and may indicate some antropic interpherence.

MEMBROS DA BANCA:
Presidente - 1522392 - GISELE MARA HADLICH
Externo ao Programa - 957.032.685-91 - SARAH ADRIANA ROCHA SOARES - UFBA
Externo à Instituição - JOSE MARTIN UCHA - IFBA