Banca de QUALIFICAÇÃO: IGOR SILVA PEREIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : IGOR SILVA PEREIRA
DATE: 28/07/2025
TIME: 14:00
LOCAL: Videoconferência - https://meet.google.com/woy-imfj-rec
TITLE:

SATELLITE-DERIVED BATHYMERY: A LOW-COST METHOD FOR ANALYZING THE CONTINENTAL SHELF OF CEARÁ

KEY WORDS:

Brazilian Equatorial Margin; remote sensing; shallow platform; Landsat 8.

PAGES: 42
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

This study presents a low-cost Satellite-Derived Bathymetry (SDB) workflow validated for depths on the shallow platform (< 20 m) off western Ceará, within the Brazilian Equatorial Margin. Cloud-free (< 10 %) Landsat 8 mosaics were compiled in Google Earth Engine, converted to surface reflectance, and the spectral values of bands B1 (blue), B2 (green) and B3 (red) were extracted. Eight empirical SDB models were then built in R, linking the multispectral layers to depth (z) and evaluated with the metrics R², RMSE, MAE and bias. The global assessment returned satisfactory results, but the depth-stratified analysis revealed the most suitable models. In waters shallower than 10 m all models improved markedly; model M7, despite a 17 % drop in R², achieved lower RMSE and MAE and the best bias (0.49 m), attributable to the combined use of bands B1 and B3. Model M6 performed best between 10 m and 20 m, driven by an R² of 0.68 (+33 %) together with reduced RMSE and MAE, a result linked to the absence of band B3 in that formulation. While every model generated acceptable SDB surfaces, the statistics indicate that M5 is preferable for depths < 10 m and M6 for depths of 10–20 m; a hybrid of these models is therefore most efficient for initial surveys of the Brazilian Equatorial Margin’s shallow platform. The study demonstrates that image-based bathymetry compensates for the regional data scarcity and supplies an essential baseline for coastal activities and shallow-water exploration.

COMMITTEE MEMBERS:
Presidente - 2042405 - MOAB PRAXEDES GOMES
Externa ao Programa - 1226434 - MARY LUCIA DA SILVA NOGUEIRA - UFRNExterno à Instituição - FILIPE EZEQUIEL DA SILVA
Externo à Instituição - PAULO VICTOR DO NASCIMENTO ARAÚJO - IFRN