USE OF GOOGLE EARTH ENGINE FOR COMPARATIVE ANALYSIS OF SHORELINE OF TWO DELTAS OF THE BRAZILIAN EAST COAST BETWEEN 1986 E 2021: São Francisco river delta (Al/Se) and Paraíba do Sul river delta (RJ)

Google Earth Engine (GEE) has provided subsidy to multitemporal searches due to its fast and free cloud processing. The deltas of the Sao Francisco River and of the Paraiba do Sul River are located on the east coast of Brazil and are categorized as wave-dominated deltas, according to Galloway (1975). The construction of its deltaic plains occurs from the incorporation of Coastal Sand Barriers (BACs) and in both cases the formation of spits occurs (BACs connected to the plain by only one of the extremities). For analyzing the spectral trajectory of the pixels between 1986 and 2021, the Landsat 5 and Landsat 8 image collections were used. For the change detection, the MNDWI index (Modified Normalized Difference Water Index) was applied. The results showed the areas of accretion and retreat of the coastline. The Sao Francisco River delta had a negative area balance of-0.1206 km(2), while the Paraiba do Sul River delta had a positive balance of 0.2318 km(2). Areas of coastal erosion were identified, which may be related to anthropic action, especially in the case of the Sao Francisco delta, due to the construction of dams in the drainage basins that alter the fluvial sedimentary load.