Abstract
The Gobi Desert in southern Mongolia has been identified as the strongest dust storm hot spot threatening public health and socio-economic activities in East Asian countries. Despite its significance, the complete mapping of the aeolian surface erosion in southern Mongolian remains unresolved because of the extensive region of interest that cannot be interpreted easily by conventional approaches. Therefore, in this study, we built a mapping scheme to define undergoing aeolian erosion and applied it over the southern Gobi Desert. The remote sensing approach applied here was based on an interferometric synthetic-aperture radar (InSAR) time series technique. A number of Sentinel-1 InSAR pairs that generate phase coherences for a certain period were synthesized via the means of principle component analysis (PCA) to extract the topographic persistence indicative of surface erosion rates. Validation analyses performed through inter-comparisons of phase coherence signals over landmark areas and residuals between global digital elevation models (DEMs) confirmed the reliability of outputs. The results revealed the geological lineaments in southern Mongolia confining sandy deposits and the sediment transportation pathways. Apparently, such bounded aeolian deposits and transportation mechanisms within geological structures have significantly contributed to dust generation in the Gobi Desert over southern Mongolia. In addition, this study demonstrated that the newly developed InSAR time series technique has great potential for identifying intensified land erosion and dust sources.
Highlights
At present, eolian surface erosion and subsequent dust generation are emerging as serious environmental threats to local communities and the socio-economical aspects of surrounding regions
To mask off the high vegetation canopy, surface creep in sloped terrain and snow cover, the threshold values of enhanced vegetation index (EVI) (0.1), and slope masks (40°) were determined to decompose the interrelationships between the phase coherence first principle component analysis (PCA) and EVI/slope
Together with the discovery of regional erosion patterns over southern Mongolia, we have proven the reliability of interferometric synthetic-aperture radar (InSAR) phase coherence approaches in the reconstruction of eolian surface erosion
Summary
Eolian surface erosion and subsequent dust generation are emerging as serious environmental threats to local communities and the socio-economical aspects of surrounding regions. Comprehensive mapping of eolian surface erosion is a high priority task in dealing with the threat of such global environmental changes effectively through the use of appropriate countermeasures. Interpretations of vegetation indices, land cover data, and topographic data have often been employed as tools to trace the susceptibility of land to eolian surface erosion and consequent dust generation. There have been no exemplary scientific contributions that directly measured the surface erosion rate by means of remote sensing techniques except for a very small number of special cases that were carried out over a limited local scale. In terms of reliability and applications, obviously there are huge differences between approaches that directly measure surface erosion rates and approaches that indirectly synthesize the involved constraints on surface erosion to forecast the erosion rates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
