Detection of surface anomalies through fractal analysis and their relation to morphotectonics (High Zagros belt, Iran)

摘要

Fractal geometry is considered as a new method for quantitative analysis and explanation of surface complexities and roughness in self-similar or self-affine landforms. In the present study, the surface fractal dimensions were investigated by a cellular model by covering divider method and remote sensing data, in a complex morphotectonic region in terms of tectonic, geological, and geomorphological structures along the margin of the High Zagros Belt. Results of this study indicated that surface anomalies can be detected by cellular fractal model due to variations at the boundary of lithological units and structural zones, and along faults that can change the characters of the fractal dimension of landforms. Investigation of wavelet analyses on two profiles of study area shows that the amplitude and frequency of the fractal dimension is related to lithological and structural zones boundaries, and to the presence of faults. In this study, the lowest fractal dimension is associated with the integrated units of Mesozoic orbitolina limestone on the border of the two structural zones of Sanandaj-Sirjan and High Zagros belt. However, the presence of friable and erodible Quaternary formations increases the fractal dimension. There is an inverse relationship between the fractal dimension and elevation and Terrain Ruggedness Index, indicating that mountains have lower fractal dimensions than lowlands. The results of the present study show that fractal dimensional changes in topographically complex zones depend on the interaction of a set of lith-ological, tectonic, and geomorphological factors, and allow for a systematic quantitative analysis of landforms.