Cave protection as a Karst conservation tool in the environmentally sensitive Lagoa Santa Karst, Southeastern Brazil

Abstract

Karst areas in densely populated and industrialized areas in Brazil are under severe environmental pressure due to urbanization, quarrying, groundwater pollution, groundwater overpumping and cave vandalism. Although karst terrains receive no specific protection according to Brazilian environmental law, caves, regardless of rock type, are classified as belonging to the society, and must be studied in detail to have their significance (and related level of protection) determined. Most caves (>90 %) are of either maximum or high significance, which results in protection of not only the cave but also of an associated buffer zone. Given the very conservative definition of cave (a natural void large enough to allow a human being to enter), hundreds of caves will exist in any given outcrop and the amalgamation of buffer zones tends to yield an integrated area that covers most of the karst surface. In the Lagoa Santa Karst, Brazil’s most urbanized and industrialized karst area, cave preservation is presently the most effective approach to protecting karst heritage. However, other karst features not connected to existing caves (e.g., covered karst, karst aquifers with no accessible caves, dolines with no associated caves) receive no specific protection. Although this heterogeneous level of protection may yield non-preserved karst areas, the remaining zones tend to be surrounded by protection belts, imposing severe restrictions on urban and mining development and associated sources of potential damage.
Key words: Environmental policy, cave protection, karst preservation, Lagoa Santa Karst.