Use of radiometrics for bioregional conservation evaluation and wildlife habitat modelling in Central Australia

Abstract

Airborne geophysical methods have traditionally been used in geological mapping and the exploration for valuable minerals. Radiometric surveys measure the distribution of uranium, thorium and potassium in the Earth’s crust, by recording the gamma-ray radiation emitted during the decay of these elements. Approximately 90% of measured gamma rays are received from the top 30 cm of the ground. These measurements enable the interpretation of rock and soil types. These data can be used to define soil types, and radiometrics may help differentiate key discharge and recharge zones at the catchment level. However, the application of airborne geophysical technologies to other areas of land and resource evaluation remains limited despite the rapid development of these technologies over the past decade. In this paper we introduce a study investigating the utility of radiometric data for predicting vegetation community patterns and wildlife habitat in the arid zone. We test for statistical relationships between the concentrations of the elements uranium, thorium and potassium and terrain characteristics such as slope and aspect. We then examine the relationship between these elements and mapped vegetation communities, and the use of radiometric data as a surrogate predictor of wildlife habitat. To the best of our knowledge, this is one of the first investigations of its type for the Australian arid zone.