A carregar...
2 resultados
Resultados da pesquisa
A mostrar 1 - 2 de 2
- Cartografia do sinclinal de Buçaco : Penedos de GóisPublication . António J. D. Sequeira; ; Medina, JorgeRESUMO: A uma escala normal de trabalho de campo (1/25000), surgem problemas na representação cartográfica de algumas das unidades definidas no sinclinal de Buçaco-Penedos de Góis, que têm espessuras de 50 metros, ou menos. Foi necessário agrupá-las. Isto conduz-nos a uma sequência litostratigráfica apresentada neste trabalho para a maior parte das separações cartográficas já efetuadas por Delgado (1908), embora com as designações criadas por autores posteriores.
- Identification of saline areas in wetlands using spectral indices and geochemical data. The case of Baixo Vouga Lagunar (Aveiro, Portugal)Publication . Rolo, R. S. V.; Silva, S. M. L.; Medina, Jorge; Patinha, CarlaABSTRACT: The Baixo Vouga Lagoon (BVL) is an important wetland on the Portuguese coastal continent that has been suffering from the destruction of its agricultural fields due to saline intrusion processes. The aim of the research was to identify areas of salinity combining geochemical data and spectral indices obtained from Sentinel 2B satellite images. The methodology was developed using images from July 2023 and February 2024, with samples taken during the same seasonal period. Fourteen spectral indices were calculated: four vegetation indices and ten salinity indices. Pearson's method was used to assess the correlation between geochemical data and the spectral indices. The Canopy Response Salinity Index (CRSI) and Salinity Index 1 (SI 1) showed the highest correlation, at 0.428 and 0.516 respectively. Despite the limitations of using optical sensor in flooded areas, the spectral response of halophyte vegetation in areas of higher salinity was crucial for its differentiation and primary delimitation of the most affected areas.