Banca de DEFESA: THIAGO CAVALCANTE LINS SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : THIAGO CAVALCANTE LINS SILVA
DATE: 06/10/2025
TIME: 08:30
LOCAL: videoconferência
TITLE:

IMPACTS AND RISKS RELATED TO CLIMATE CHANGE ON THE COAST OF BRAZIL'S SEMI-ARID REGION

KEY WORDS:
PAGES: 160
BIG AREA: Ciências Humanas
AREA: Geografia
SUMMARY:

This study was conducted on the northern coast of Rio Grande do Norte, in a semi-arid region characterized by a low coastline, where flooding events occur repeatedly. Given this scenario, we sought to analyze three complementary methodological stages in an integrated manner, conceived as multidirectional vectors of action. The investigation was based on the use of open elevation data, freely accessible regional tide gauge records, and the application of robust statistical analyses in order to meet the specific objectives and test the proposed hypothesis. In terms of results, each chapter made relevant contributions. The first chapter aimed to identify the main hydrodynamic forcing factors and understand the physical domain of the northern coast of Rio Grande do Norte through the SMC-Brazil system. The simulations revealed wave propagation patterns conditioned by local bathymetric features, such as sandbanks and submarine canyons, confirming that such irregularities play a central role in coastal dynamics. Significant heights ranged from 0.57 m to 2.30 m (1948–2008), with 78.6% of records below 1.4 m, values consistent with historical regional observations. The second chapter focused on the calibration and multi-criteria evaluation of free Digital Elevation Models (DEMs). Fourteen global products were analyzed and compared to a high-precision geodetic network. After calibration, all models showed improvements of more than 8% in accuracy. Copernicus DEM (COPDEM) performed best, achieving an RMSE of less than 0.30 m in flat areas, while FABDEM performed well in different contexts. The final clustering grouped the models into five performance levels, providing methodological support for choosing altimetric bases in coastal studies of flat areas with limited monitoring. The third chapter consolidated the previous findings in regional modeling of tidal flooding scenarios, integrating astronomical and meteorological tides and projections of mean sea level rise. Maximum elevations of 2.975 m and 3.454 m were identified, associated with 20-year return periods. Although meteorological tides showed a reduced average contribution (≈ 0.11 m), episodic events with greater impact were observed. In extreme scenarios, about 14% of the total area of Costa Branca (≈ 730 km²) may be affected, especially in the estuarine areas of the Piranhas-Açu and Apodi-Mossoró rivers. Cities such as Macau, Areia Branca, and Porto do Mangue had a higher recurrence of potentially flooded days, between 60% and 80% in the most severe scenarios. Estimated economic losses exceeded R$ 194 million (≈ US$ 35 million), with emphasis on land and residential areas in low-lying urban sectors. The results confirmed the thesis's central hypothesis: the use of open, calibrated data integrated into multi-criteria methodologies makes it possible to consistently identify areas susceptible to tidal flooding in semi-arid regions with limited infrastructure. The sequence of analyses, forcing factors, altimetric calibration, and modeling provided a replicable, low-cost framework with direct applicability to adaptive coastal planning.

COMMITTEE MEMBERS:
Presidente - 2506087 - MARCO TULIO MENDONCA DINIZ
Externo ao Programa - 3342435 - ANTONIO RODRIGUES XIMENES NETO - UFRNExterno ao Programa - 1112649 - JOSE YURE GOMES DOS SANTOS - UFRNExterno à Instituição - BRUNO FERREIRA - UFAL
Externo à Instituição - FELIPE GOMES RUBIRA - UNIFAL-MG
Externa à Instituição - LIDRIANA DE SOUZA PINHEIRO - UFC