Evolução geoambiental das dunas de transpasse do estado do Ceará

Abstract

The bypass of dune fields in the state of Ceará have different geo-environmental contexts and among the other geomorphological elements of the coastal zone, they experience an intense process of adulteration, whose complex environment requires a particularized examination of the current situation of this fragile environment. The coastal dunes in Ceará meet prominent role in the current sediment dynamics to contribute to the balanced distribution of sediments along the coast, through the coastal bypass process, a delicate and meaningful mechanism that promotes balance in sediment distribution, especially over natural obstacles (headlands). These dune fields, responsible for bypass process, are the object of this survey, conducted in five (5) sectors of Ceará (Ponta Grossa, Iguape, Pecém, Paracuru and Jericoacoara), representing the necessary analysis and interpretation of the space environment -temporal. Thus, the thesis was the fundamental objective of the realization of geoenvironmental analysis of bypass dune fields in a spatial area compartmentalized in two (2) different times, the years 1958 and 2014. For this was taken as a methodological basis for analysis geoenvironmental, theoretical support for the activities and relevant technical, from thematic mapping, using specific software. The spatiotemporal analysis from visual interpretation of aerial photographs and satellite images, in different historical contexts, promoted the understanding of the environmental and socio-spatial dynamics in the studied sectors. In all areas there was a decrease mapped the extent of the dune field. Blocking the areas bypass, during human activities is partly in the areas of Iguape and Paracuru beaches and in its entirety, on the coast of Pecém, areas with higher anthropogenic occupations among the sectors analyzed. The coastal bypass is free in Ponta Grossa beach and Jericoacoara, where human activities are still restricted. Changes in the morphological dynamics of dunes in Jericoacoara, with intensified formation of dunes barchans admit the decrease in sediment supply to dunes along the coastal strip. Confirmation of reducing areas of dune fields, as well as their contribution of sediments and the intensification of the use and occupation of coastal environments for various purposes raises a troubling environmental framework and indicates the importance of environmental planning and the use of restraint and more intense occupation for the areas of mobile dunes, with the risk of extinction of this environmental heritage of Ceará coastal zone.