A model of weathering intensity for the Australian continent
Authors / CoAuthors
A weathering intensity index (WII) over the Australian continent has been developed at a 100 m resolution using regression models based on airborne gamma-ray spectrometry imagery and the Shuttle Radar Topography Mission (SRTM) elevation data. Airborne gamma-ray spectrometry measures the concentration of three radioelements - potassium (K), thorium (Th) and uranium (U) at the Earth's surface. The total gamma-ray -ux (dose) is also calculated based on the weighted additions of the three radioelements. Regolith accounts for over 85% of the Australian land area and has a major in-uence in determining the composition of surface materials and in controlling hydrological and geomorphological processes. The application of a stepwise forward multiple regression for the second model generated a weathering intensity index equation of:
WII = 6.751 + ? 0.851 - K+ ? 1.319 ? Relief + 2.682 - Th/K + ? 2.590 - Dose. The WII has been developed for erosional landscapes but also has the potential to inform on deposition processes and materials. Interpretation of the WII from regional to local scales and its application in providing more reliable and spatially explicit information on regolith properties are described.