Usos da terra e vulnerabilidade ambiental no estuário-lagunar do Guriú, costa oeste do Ceará

Abstract

The coastal zone has important ecosystems, among them the estuaries, considered nurseries, because they have an enormous biodiversity and a high primary productivity, with that there is an occupation of these areas, bringing significant impacts, in the area of study stands out the occurrence of the sandy barrier associated to the estuary, being a morphological feature parallel to the coast resulting from the depositional and dynamic processes associated with the marine and estuarine environment. The purpose of this study was to characterize land use patterns to identify vulnerabilities and potentialities, as well as to map the evolution of the sandy barrier of the Guriú River estuary located between the municipalities of Jijoca de Jericoacoara and Camocim, on the west coast of Ceará. Through the characterization of environmental variables, geology, geomorphology, pedology, vegetation, climate and hydrography, a geoenvironmental analysis was carried out, and from satellite images the land uses and morphological evolution of the sandy barrier associated to the estuarine lagoon system at the over the years. Land uses are identified: apicum / salted, aquaculture, building / edification area, degraded area / exposed soil, sandy barrier, dune field, anthropogenic vegetation / reforestation, natural arboreal / shrub vegetation and natural mangrove vegetation. The sandy barrier presented a variation of 80 meters in its length during the years 2006 and 2017 and an average width in its points of: point 1, 63,10m; point 2, 85.59m; point 3, 128.92m; item 4, 202.09m; point 5, 135.55m; item 6, 107.81m; item 7, 83.16m; item 8, 105.37m; item 9, 140, 37m; item 10, 201, 79m; Item 11 220.47; and point 12, 4.13m. Three systems and six environmental subsystems were identified, with very high vulnerability, the mobile dune field, the beach strip, the fluvial plain, and the lacustrine plains, medium to high vulnerability, in the pre-coastal areas of the anthropic or degraded and, finally, presented low vulnerability to very low also the pre-littoral tray associated with natural vegetation. The use of geosystemic analysis together with land use has served as the basis for the environmental management of the area, aiming at its sustainable use and improving local quality of life