Abstract
Gamma-ray attenuation caused by rainforest dispersion compared to Vegetation Index: estimates on the effects in airborne gamma-spectrometry data – example from the State of Rondônia, Amazonia, Brazil
Highlights
Potassium, uranium, and thorium are the only naturally occurring chemical elements whose radioactive decay produces gamma radiation with sufficient energy and intensity to be measured in airborne geophysical surveys (Minty et al 1997)
The aim of this work is to estimate the magnitude of radiometric signal attenuation in rainforest regions, comparing the signal obtained for the four investigated channels of gammaspectrometric data (Total Count - Total Count of Radiation (TC), potassium - K, equivalent thorium - eTh, and equivalent uranium - eU) in wooded and deforested areas and understand the causes of this phenomenon
The data used in this analysis comprise four channels from gamma-spectrometric survey (Total Count, potassium, equivalent thorium and equivalent uranium), and elevation from airborne Digital Elevation Model (DEM) and Normalized Difference Vegetation Index (NDVI) values
Summary
Uranium, and thorium are the only naturally occurring chemical elements whose radioactive decay produces gamma radiation with sufficient energy and intensity to be measured in airborne geophysical surveys (Minty et al 1997). This property, associated to the fact that the radiogenic isotopes of these three elements are distributed among the stable isotopes in nature, makes the airborne gamma-spectrometry a reliable tool for modern geological mapping and for qualitative comparisons of the concentration and distribution of these elements in the land surface. The processing of airborne spectrometry data is not trivial and depends on many environmental factors that must be corrected for a standard interpretation, such as flight height, air and soil moisture, and the presence of vegetation (IAEA 2003)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have