A Novel Multidimensional Perspective on Dynamic Characteristics of the Peculiar Feather-Shaped Dunes in Kumtag Desert With Time-Series Optical and SAR Observations

Abstract

As a world-class problem that has confused the field of geoscience for a long time, the formation mechanism of the peculiar feather-shaped dunes in Kumtag Desert has not been clarified due to the deficiency of a comprehensive investigation on the dune dynamic characteristics. Because of the quickly changeable dune morphology and sands’ low dielectric constants, the traditional single technique generally was only used to identify or quantify dune mobility in one or two dimensions, and cannot retrieve the complete information of dune dynamic characteristics. To overcome these deficiencies, a comprehensive study of confusing the optical image cross-correlation, synthetic aperture radar (SAR) offset-tracking, and small baseline subsets interferometric SAR (InSAR) and InSAR coherence was performed here to identify and quantify the movements of feather-shaped dunes from a mutidimensional (East–West, North–South, slant-range, azimuth, and coherence) perspective. These results showed that the feather-shaped dunes demonstrate a movement tendency from the northeastern to the southwestern orientation (204.32° ± 52.15°) with the displacement magnitude of 3.34 ± 2.26 m/year, in consistent with the predominant wind condition. Specifically, the spatial heterogeneity was found that these dunes move along a relatively small slope gradient (0°–6°) and a northwestern–southeastern facing slope aspect (300°–350°, 120°–180°). Besides, the large displacement velocities are mainly concentrated in the pinna rachis rather than the rami of the feather-shaped dunes. This article sheds a light on the comprehensive investigation on the large-scale dynamic characteristics of peculiar feather-shaped dunes by combining the medium-resolution optical and SAR satellite observations.

Keywords

• Feather-shaped dunes
• Kumtag Desert
• multidimensional dynamic characteristics
• optical image cross-correlation
• synthetic aperture radar (SAR)
• spatiotemporal evolution