Relationship between soil properties and airborne gamma-radiometric data

Abstract

Soil is a fundamental natural resource; it is the basis of human agriculture. Present development in sustainable land-management and precision agriculture has increased the need for reliable and comprehensive information concerning the land surface in terms of soil spatial distribution and soil properties. Traditional soil maps often fail to provide the high-resolution soil data that is now required to sustainable land-management practices and there is a stronger need to understand soil variation at a finer scale than previously demanded. Comprehensive soil survey data from more than 1700 soil profiles has been collected by Department of Water, Land and Biodiversity Conservation for the Angas Bremer district which is located near Strathalbyn, approximately 60km south east of Adelaide. In addition, the area was a core area for the National Action Plan for Salinity and Water Quality. As part of this programme, airborne radiometric and electromagnetic surveys were conducted. Spatial scales of variability of both ground-surveyed soil conditions and remotely sensed indices of soil variability (radiometrics, electromagnetics) are assessed and contrasted. In order to evaluate the conditions under which higher resolution remotely sensed and GIS data can be applied to soil mapping, we present relationships between soil properties and terrain and geophysics data and discuss implication for the future mapping approaches.