Natural Determinants of the Earth-Mound Fields Distribution in the Southwest of the State of Goiás

Abstract

Murundusfields, also known as covoais,are frequent microreliefs in the Cerrado. These are sets of semicircular elevations that protrude from the surface of the land, rounded or oval, with average dimensions of 70 cm in height and 6 m in diameter. The determinants of its regional spatial distribution are still poorly known. This study aimed to identify the natural determinants of its spatial distribution in the Southwest of Goiás, in the Sedimentary Basin of Paraná. All occurrences of murundusfields identified by the project Mapping of Remnant MurundusFields in the state of Goiás (SEMAD-GO/LAPIG-UFG) were compared with information referring to lithology, geomorphology,NDWI (Normalized Difference Water Index), and SMI (Soil Moisture Index). The indices were obtained from SENTINEL 2-A (MSI) and Landsat 8 (OLI and TIRS) orbital images. It was found that murundusfields preferentially occur in the Alluvial Deposits, Cachoeirinha, Detritic-lateritic Covers, and Serra Geral geological units. Murundusfields predominate under slopes of 0 to 8% (flat to gently undulating relief), and in areas with lower drainage density. The NDWI and the SMI indicated that murundusfields are concentrated on wet surfaces, occurring less frequently in saturated/very wet areas and in moderate humidity, dry, and very dry surfaces.