Banca de DEFESA: Bárbara Costa da Silva

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Bárbara Costa da Silva
DATE: 21/07/2022
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Lateritic regolith mapping in Midwest of Brazil by multispectral remote sensing

KEY WORDS:

lateritic duricrusts, weathering, data integration and modeling, statistical methods, cloud processing.

PAGES: 67
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

In central Brazil, there is a thick mantle of weathering developed from different types of rocks and geomorphic surfaces, with a wide occurrence of lateritic crusts and their products. The mapping of regolith units, especially the lateritic duricrusts, provides information of great interest to mineral exploration and the understanding of evolutionary processes in landscapes, especially those in a tropical environment. The development of GIS tools, the robustness of mathematical and statistical models for data processing and analysis, and cloud computing represent advances in large-scale geological mapping, in addition to providing relevant information about tropical lateritic terrains. Remote sensing data and image processing techniques are effective in mapping these surfaces, whether using band ratios or principal component analyses. There are several methods used in remote sensing for mapping the regolith. In this work, were tested three mathematical and statistical techniques in multispectral images from Landsat-8 OLI/TIRS and Sentinel-2 MSI sensors, to verify the one with the best efficiency for the study area: 1 — band ratios (BR), 2 — analysis Principal Components (DPCA) and 3 — Index Overlay (IOM). Data processing was performed on the Google Earth Engine cloud platform and allowed the discrimination of areas where rock, saprolite and lateritic crusts outcrop, in the border region of the states of Goiás, Distrito Federal, Minas Gerais and Bahia, in the center-west of the state. Brazil. The predictive maps had an overall accuracy greater than 70% and k and t values close to 0.6, indicating a strong correspondence with the field data. Among the sensors, Landsat-8 had better agreement with field data than Sentinel-2 data. Thus, the models applied to OLI and MSI images, validated by field data, show the effectiveness of using multispectral data for mapping regolith units in tropical conditions, which can be easily applied and tested in other study areas.

BANKING MEMBERS:
Externo à Instituição - VINICIUS HECTOR ABUD LOURO - USP
Presidente - 1210338 - ADRIANA MARIA COIMBRA HORBE
Externa ao Programa - 1129464 - JULIA BARBOSA CURTO MA