Banca de DEFESA: MAURÍCIO DA ROCHA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : MAURÍCIO DA ROCHA
DATA : 31/10/2019
HORA: 15:00
LOCAL: Campus Sosígenes Costa - Sala Taperapuã 1 - Link: https://mconf.rnp.br/webconf/csc-1
TÍTULO:

SALT INTRUSION IN THE BURANHÉM (SOUTH BAHIA) RIVER ESTUARY THROUGH NUMERIC MODELING   

PALAVRAS-CHAVES:

continent-ocean interaction, watersheds, Discovery Coast, Delft3D, coastal zones.   

PÁGINAS: 63
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

The city of Porto Seguro, Bahia, is a well-known tourist destination in Brazil. However, its urban infrastructure is overloaded, especially during the summer. The annual fluctuating population is approximately 10 times larger than its fixed population. A combination of growth of fixed and fluctuating variations, without medium and long term, further pressing the sanitation of the municipality, making them indispensable studies that can show the possible environmental impacts to aid in urban planning. By 2025, according to the agreement with the National Water Agency, it is estimated that the Buranhém River will also be used as financial supply management for the city. The estuary tends to decrease river flow mainly due to forest degradation in the watershed and influence of phenomena such as the southern El Niño (ENSO) oscillation. Its flow suffers great annual variation, being a historical average annual flow of 22 m³.sˉ¹. A region is subjected to an astronomical micro-tidal and meso-tidal regime with restrictions above 2m, with media speeds close to 0.4m.s^-1 in flood and 1m.s^-1 in ebb. The present work has as general objective or saline intrusion study in the Buranhém river estuary in scenarios of minimum flows recorded in historical series. To this end, a hydrodynamic numerical model was implemented to support local sanitation planning and to contribute to studies related to sediment transport and water quality. Scenarios were simulated under different tidal conditions and river flows. The model was calibrated and validated through field data of current velocity, water level variation and surface and bottom salinity, observed with the aid of CTD and ADCP, based on three fixed points in the estuary. The observed salinity data show a more stratified environment at neap tide compared to the spring tide, while the model showed characteristics of a well-mixed environment at both tide. Field data and modeled results were quantitatively compared using the Skill parameter. For the purpose of saline intrusion analysis, in addition to the typical tides of the region, the model was forced with minimum flows recorded in historical series (2, 4, 6 m³.s^-1) and in an extreme minimum flow condition of 0.2 m³.s^-1. As a result, average Skill values higher than 0.97 were obtained for the water level, under neap tides and spring tides with variations of 1 m to 2.15 m respectively. Surface and bottom salinity results were mean Skill values greater than 0.90, while horizontal velocity results with average Skill values greater than 0.77. The field data presented a saline intrusion of 9.4 km under a river discharge regime of ~ 12 m³.s^-1, whereas the model represented a saline intrusion in the condition of extreme minimum flow and spring tide of approximately 17 km upstream of the estuary mouth. In simulations with minimum flow rates of (2, 4, 6 m³.s^-1), the intrusion gradually decreased with the results of 13, 11 and 9.5 km, respectively. Confirming the scenario of using the Buranhém river as a source for water supply in Porto Seguro, studies such as this are a reference to determine a safer catchment region.    

MEMBROS DA BANCA:
Externo à Instituição - ALESSANDRO LUVIZON BÉRGAMO - UNIFEI - UNI
Presidente - 962.287.925-04 - ALLISON GONÇALVES SILVA - IFBA
Externo à Instituição - CARLOS AUGUSTO FRANÇA SCHETTINI - UFPE
Externo à Instituição - EDUARDO SIEGLE - USP