Sensoriamento remoto e SIG aplicados à análise da evolução espaçotemporal da linha de costa do município de Icapuí, Ceará - Brasil

Abstract

The coastline is a dynamic environment and its constant morphodynamic adjustments resulting from natural and human processes. The municipality of Icapuí is situated at the eastern end of the state of Ceará - Brazil, has approximately 45 km of coastline and is one of the most complex environmental systems of Ceará, with varying morphologies of Quaternary origin, which are preserved stretches and impacts of human actions. The main objective of this research is to analyze the evolution timeline (1987-2014) of the coastline of Icapuí, analyzing in an integrated manner the local coastal dynamics. The research was conducted in five main stages: bibliographic and cartographic survey, field work, preparation and database analysis in GIS, the diagnosis of evolution with the development of cartographic products and projection scenarios. The coastal plain was compartmentalized into three sectors studies (west, central and east) and used four mathematical and statistical procedures extension "Digital Shoreline Analysis System 4.3" (DSAS) for ArcGIS 10.1, which allowed to compare the shorelines multitemporal extracted from remote sensors products through a base line and transects spaced 500 m apart. It was possible to estimate in meters, considering the clip timeline, the maximum variation (NSM), the absolute variation (SCE), the mean annual change (EPR) and annual linear regression trend (LRR). Assigns to the coastline five classes according to the processes identified in the sections, as follows: progradation continuous, mo*derate progradation and / or semi-relative stability, moderate erosion and / or semi-continuous and continuous erosion. It was evident that the most relevant progradational and erosive processes are present in the western sectors, subsectors erosion Retiro Grande, Redonda and Peroba with trends of -0.5 to -4 m / year, and central sectors with significant decreases in Barreiras da Sereia subsectors and Barrinha, that a decline of up to 115 meters in 27 years and trends between -1.2 and -4.5 m / year, with varying social and environmental impacts, while the eastern sector showed relative stability. From this, it was possible to discuss containment strategies erosion, project possible evolutionary scenarios and suggest directions for planning and management of the coastal zone of the municipality.