ECODINÂMICA DA PAISAGEM PALEODUNAR DO MÉDIO RIO SÃO FRANCISCO/BA: EM DEFESA DAS FRONTEIRAS AGREDIDAS

Abstract

The northeastern semi-arid region is home to one of the largest wind farms in Brazil, where numerous bodies of inactive dunes are located. The climatic and environmental changes that occurred during the Quaternary are intrinsically linked to the genesis and evolution of the sandy deposits in this region, taking as evidence their environmental characteristics and morphological disposition. The present investigation sought to understand the ecodynamics of the dune landscape, guided to identify the morphodynamic and morphoclimatic processes and the levels of stability of this environmental system, aiming at the preservation/conservation of this ecoregion. Although the investigated area is in the Environmental Protection Area - APA Dunas e Veredas do São Francisco, the process of occupation and use of the soil and the removal of native vegetation have caused impacts of varying dimensions. In this regard, the aforementioned ecosystem presents a great risk of progressive destruction, being subject to various impacts due to the inappropriate use of the small valleys that cross the paleodunes, the anastomosed trails made by animals, the removal of native vegetation - the caatinga -, the removal of sand dunes and the transposition of the São Francisco river, which will significantly reduce the volume of water in this water body. The method adopted is based on the morphodynamic approach proposed by Tricart and in the Geosystemic Theory. The results indicate strong degradation linked to inadequate land use and the indiscriminate removal of vegetation that becomes a morphological dynamic with a predominance of instability. In this way, it was possible to map the genesis of natural and anthropic factors and processes that determine the intensity of the degree of environmental impact, as well as to deduce palliative and permanent measures to revert it. In this sense, it is essential to monitor erosion processes, conserve/preserve the native forest and implement a management policy for land use and occupation based on the precepts of socio-environmental sustainability.