The study site is situated in the Cretaceous Bragança-Viseu coastal basin. The holocenic
evolution of this area is marked by muddy progradation over a submerging coast, where is
developed one of the most mangrove system of the world, with almost 6,000 km2.
This research has showed that orbital remote sensing data can provide excellent geologic
and coastal land use information. The SAR RADARSAT-1 imageries represent a powerful tool to
understand the coastal processes in the wet tropical environments, mainly in the mangrove coasts.
This fact is related to microwave radiation can be interpreted for Amazon coastal zone mapping
and monitoring, because SAR image constitutes in the unique source of data with all-weather
remote sensing capability, in response to difficulty to get optical images in the Amazon, due to
all-time cloud cover.
Landsat TM imageries are excellent data sources to integration with RADARSAT-1. They
present a good performance in coastal environments discrimination. The remote sensing data
integration allow a synoptic view of the area and provide geobotanic (relation between coastal
environment and vegetation) and multitemporal information. In addition to integrated data,
geographic information system (GIS) combines different data sets and simultaneously interprets
the spatial and temporal relationship between various coastal environments. This way, GIS
allows for a more comprehensive, accurate and easier interpretation of a geomorphologic
mapping under an organizational philosophy to control data towards use the information to
coastal zone management.
The application of remote sensing data in the tropical coastal studies was used in different
approaches. In relation to spatial and temporal variability of the shoreline, this study has revealed
that during the Holocene, the coastal plain is marked by a muddy progradation. However, from
the analysis of the remote sensing images were possible investigate the shoreline variability under
long (1972-1998) and short (1985-1988, 1988-1990, 1990-1991) term, which is characterized by
shoreline retreat, probably due to climatic changes, such as El-Niño and La-Niña events. These
climatic events control the rainfall along the coastal zone, where severe erosional period (1985-
1988) are coupled with high precipitation rate (> 4,000 mm/yr.).
From the point of view of the spatial analysis of the coastal changes, the mangroves
constitutes one of the most environments to be analyzed by remote sensing images, as in the
electro-optical spectrum due to their high reflectance in the infrared, as in the microwave due to
their rough surface responsible for high backscattering. Therefore, mangroves have showed to be
an excellent geologic indicator to detect and to quantify short and long-term morphological
coastal changes.
To conclude, remote sensing data integration, GIS and auxiliary fieldwork data present a
fundamental role to the integrated coastal zone management, environmental risk assessment,
local characterization of the study sites, base maps upgrading and information dissemination for
public consultation, which are all significant factors in this decision-making process.
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