GIS-Based Relief Compartment Mapping of Fluvio-Karst Landscape in Central Brazilian Highlands

Abstract

The present study describes the preliminary findings of a research project aiming at creating a knowledge-base for the protection of caves heritage at Rio Vermelho preservation area in the central Brazilian highlands. A GIS-based
relief compartment mapping was conducted using readily available data (e.g., satellite images, geological, and cave
location maps). Four resultant geomorphological domains were identified, including (i) lowlands (282 km2) with a base
level in silicates and carbonates, (ii) the karst terrains (994 km2) which were developed in carbonates trapped by siltstone
lenses, (iii) the talus (1483 km2) having colluvial and alluvial units deposited by the escarpment retreat (Urucuia
Formation) and (iv) the highlands (1143.7 km2) developed over the sandstone of the Urucuia Group. The intersection of
landform and geological maps resulted in delineating two abrupt contacts, the first between lowland and karst terrains
and the second between the talus and highlands that formed canyon escarpment. For sustainability perspective, this study
proposed two types of cave systems in the region as superior/vadose (top-bottom) that collect floods from hillslopes and
deep Epigene fluvial-karst (bottom-up).

Keywords: Cave heritage, Epigene fluvio-karst, geomorphological domains, vadose cave.