Article
Boolean and fuzzy methods for identifying lateritic regoliths in the Brazilian Amazon using gamma-ray spectrometric and topographic data.
Registro en:
IZA, Edgar Romeo Herrera de Figueiredo; HORBE, Adriana Maria Coimbra; SILVA, Adalene Moreira. Boolean and fuzzy methods for identifying lateritic regoliths in the Brazilian Amazon using gamma-ray spectrometric and topographic data. Geoderma, v.269, p.27-38, 2016.
Autor
IZA, Edgar Romeo Herrera de Figueiredo
HORBE, Adriana Maria Coimbra
SILVA, Adalene Moreira
Institución
Resumen
Airborne gamma-ray spectrometry is relatively well understood when associated with rocks, but the response
and radioelement distribution in weathered materials is less known. This work used airborne gamma-ray spectrometry
and altimetry to identify domains with higher probability of occurrence of lateritic crust and dismantling
products in an area located in the west of the Brazilian Amazon. Map algebra was used through the
Boolean and fuzzy techniques to create predictability digital models highlighting favorable areas for the occurrence
of lateritic crusts. The Index Overlay Method was used in the Boolean technique. The fuzzy technique
used the fuzzy algebraic product operator, fuzzy algebraic sum operator, and fuzzy gamma operator. Both models
showed good correlation between the favorability predicted and the presence of crusts in the field, however, the
fuzzy model showed higher correlation and highlighted areas not identified by the Boolean model. In contrast,
the Boolean model allowed the visualization of the areas related to the influence of each variable or its possible
combinations individually on the final map. Thus, the identification of lateritic crusts based on mathematic
models applied to altimetric and airborne gamma-ray spectrometric data is a new tool that will contribute significantly
to geological mapping and to the understanding related to the response and radioelement distribution in
weathered materials.