Integrated Landscapes of the Coastal Municipalities of the São Francisco River mouth, Brazil

Abstract

In coastal environments, the complex dynamics are characterized by the influence of oceanographic, hydrological, climatic, geological and anthropic factors that result in different landscape units. In this sense, the objective of this work was to classify and analyze the landscape units considering the geocomplexes and geofacies of the municipalities of Piaçabuçu / AL and Brejo Grande / SE. The methodological sketch of the geosystemic approach guided the research, which was developed through bibliographical revision, survey and processing of cartographic data and creation of thematic maps. The processes of marine, fluvial and wind origin associated to the sedimentary package that integrates the Continental Formations of the Quaternary allowed the formation of environments with distinct characteristics that integrate the three geocomplexes - Coastal Plains, Marine Terraces and Fluviolagunar Plain integrated by fourteen geofacies. In recent years, the fluvial plain has presented some changes related to the process of marine erosion and shrimp farming activities, as a result of changes that occurred in the dynamics of the São Francisco River. As for the marine terraces, in Piaçabuçu they occur interspersed with depressions formed between the coastal cords, predominating like use the coconut-bay culture. In Brejo Grande, the sandy sediments of the Holocene marine terraces have advanced on the fluvial plain, partially altering the vegetation of the mangrove. In the environments that comprise the fluviolagunar plain of the municipalities, there are changes in the pertinent aspects to the use and occupation of the soil. Thus, from the mapping with satellite images from 1984 and 2017, it was possible to conclude that the natural processes associated with anthropic action are providing readjustments to the dynamic balance of the landscape.