The use of Remote Sensing techniques and empirical tectonic models for inference of geological structures: Bridging from regional to local scales

摘要

Practical and economic constraints prompt the need of obtaining structural geological information with reduced field effort. This paper presents a methodological strategy for deriving such information from remotely sensed (RS) images coupled with empirical tectonic models as a way of bridging from regional to local scales. The hypothesis that spatial organisation displayed by small-scale tectonic structures (and not only the large ones) could be correlated with the arrangement of natural linear features observed on RS imagery to allow inferences on the local geological structure was tested. Azimuth direction and subsidiarily length were found to be the most appropriate attributes for spatial characterisation and comparative analyses of line sets. Inferences made of tectonic structures and respective directional arrangements were based on a combination of qualitative (visual analysis of histograms) and statistical methods (non-parametric goodness-of-fit tests). The numerical evaluation of the results of tests expressed in terms of average degree of matching (91% to 95%) and errors (5% of omission errors and 31.2% of commission errors) showed a reasonable efficiency of the inferential approach in predicting the structural geological settings in lithological units as well as in mid-size areas (50 to 80 km{sup}2 approximately). Potential applications of the inferential approach in terrain evaluation schemes, particularly for planning and engineering-related purposes, are envisaged.