INFLUENCE OF HYDROGEOLOGICAL ASPECTS OF KARST AQUIFERS ON EVOLUTION OF LANDSCAPE: IN THE CHAPADA DIAMANTINA, BAHIA, BRAZIL

The present work discusses how the hydrogeological functioning of the karst aquifer conditions and interacts with the morphological evolution of the ladscape located in the central portion of the Chapada Diamantina, Bahia, Brazil. This karst system houses a relevant speleological sites in the country. The region is the scene of important scientific discoveries, particularly related to speleology and evolution of karstic ladscape. However, the understanding of the relationships between morphology and groundwater hydraulics is still little explored. For this purpose, comparative studies were performed between the morphological features of the terrain and specific capacity data of tubular wells, supported by hydrogeochemical and stable isotope data (delta C-13). The surface features of the terrain showed a correlation with the specific capacity data, mainly considering the distribution of dolines. When compared with depth, the specific capacity data presented two intervals of higher productivity: the first for wells with less than 60 meters depth, and the second for wells with depth ranging between 91 and 120, suggesting a greater hydraulic connection in these class intervals. The morphological evolution of the study area is probably intrinsic to the coalescence of two distinct karsification processes: hypogenic karsification and epigenetic, which connote different characteristics of the system.