Application of Database Approaches to the Study of Earth’s Aeolian Environments: Community Needs and Goals

Scuderi, L. A.; Weissmann, Gary S.; Hartley, Adrian J.; Yang, Xiaoping; Lancaster, Nicholas

doi:10.1016/j.aeolia.2017.05.004

Cited by 14 publications

(9 citation statements)

References 196 publications

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“…Even though the barchans look relatively crisp, their edges are often gradational and an exact position is often subjective (see Scuderi et al [26] for a discussion on the issues of quantifying the fuzzy edges of aeolian objects). Therefore, to reduce the uncertainty related to the fuzzy edges when outlining the selected dunes, we have enlarged every satellite image at a scale of 1:250 before drawing the dune's contour by hand.…”

Section: Dune Migrationmentioning

confidence: 99%

Migration and Morphology of Asymmetric Barchans in the Central Hexi Corridor of Northwest China

Zhang

Dong

et al. 2018

Geosciences

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Crescent-shaped barchan dunes often display an asymmetric shape, with one limb longer than the other. As shown in previous studies, asymmetric bimodal winds constitute one major cause of barchan asymmetry, but the heterogeneous conditions of sand availability or flux, as well as topographic influences, may be also important. Understanding the morphology and dynamics of asymmetric barchans may have an impact in a broad range of areas, particularly as these dunes may serve as a proxy for planetary wind regimes and soil conditions in extraterrestrial environments. However, in addition to the existing theories and numerical models that explain barchan asymmetry, direct measurements of migration rates and morphologic changes of real asymmetric barchans over a time span of several years would be beneficial. Therefore, here we report such measurements, which we have acquired by investigating asymmetric barchans in the Hexi Corridor, northwest of China. We have found that dune interactions and asymmetric influx conditions are the most important causes of barchan asymmetry in this field. Particle size distributions in the Hexi Corridor display strong variations over different parts of the asymmetric barchans, as well as over different dunes, with gravel particles being incorporated from the substrate as the dunes migrate. Our observations have shown that upwind sediment sources are important for dune formation in the Hexi Corridor, and that interdune interactions affect dune shape in different ways, depending on their offset. The asymmetric barchans in the Hexi Corridor are active, with an average migration rate (MR) between 8 and 53 m year −1 , in spite of the different asymmetric shapes. Our data for dune migration rates can be described well by a scaling of MR = A/(W + W0), where W is the barchan cross-wind width, A ≈ 2835 m 2 s −1 , and W0 ≈ 44 m. A similar scaling fits very well the migration rate as a function of dune along-wind width L, (i.e., MR = B/(L + L0), with B ≈ 1722 m 2 s −1 and L0 ≈ 13 m). Linear relations are also found between both dune widths and the average limb and windward side lengths, thus indicating that the morphometric relations that are predicted from models for steady-state, symmetric crescent-shaped dunes can be applied to different transitional morphologies of interacting, asymmetric barchans.

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Section: Dune Migrationmentioning

confidence: 99%

Migration and Morphology of Asymmetric Barchans in the Central Hexi Corridor of Northwest China

Zhang

Dong

et al. 2018

Geosciences

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“…Although barchans are one of the simplest dune types, it is nonetheless difficult to accurately define their edges (Scuderi et al, 2017). In our measurement and analysis of the dune morphology and migration rate, an important problem is the uncertainty and fuzziness of the boundaries of the dunes.…”

Section: Definition Of Dune Migration Rate and Directionmentioning

confidence: 99%

“…In our measurement and analysis of the dune morphology and migration rate, an important problem is the uncertainty and fuzziness of the boundaries of the dunes. Although barchans are one of the simplest dune types, it is nonetheless difficult to accurately define their edges (Scuderi et al, 2017). To minimize this problem, we magnified the satellite images as much as possible (up to a scale of 1:250) before we drew the outlines.…”

Section: Definition Of Dune Migration Rate and Directionmentioning

confidence: 99%

Migration of barchan dunes in the western Quruq Desert, northwestern China

Yang

Dong

Liu

et al. 2019

Earth Surf Processes Landf

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Barchan dunes are common on Earth, Mars and Titan. Previous studies have shown that their formation, migration and evolution are influenced by the wind regime and other factors, but details vary among regions. Understanding barchan morphology and migration will both improve our understanding of dune geomorphology and provide a basis for describing the environmental conditions that affect the formation and development of these dunes on Earth and other planets. Here, we provide detailed measurements of barchan dune migration in China's Quruq Desert, in the lower reaches of the Tarim River. We monitored their migration direction and rate, and their morphological changes during migration, by comparing Google Earth images acquired in 2003 and 2014. The dunes migrated west‐southwest, close to the local resultant drift direction. The migration rate averaged 8.9 to 32.1 m year−1, with obvious spatial variation. In addition to the wind regime, the migration rate depended on dune morphology, density and vegetation cover; the rate was negatively related to dune height, density and vegetation cover, but positively linearly related to the length/width ratio (LU/W) and to the decrease in this ratio from 2003 to 2014. We found correlations among the dune morphometric parameters, but the relationships were weaker than in previous research. Due to the complexity of the factors that affect the processes that underlie sand dune development and migration, the morphological changes during dune migration were also complex. Our measurements suggest that the aeolian environment played a dominant role in dune migration and its spatial variation in the Quruq Desert. These results will support efforts to control dune migration in the western Quruq Desert and improve our understanding of dune morphodynamics. © 2019 John Wiley & Sons, Ltd.

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“…The lack of an objective and systematic approach to quantify dunes limits our ability to analyze these environments and broadly characterize them [29]. Extraction and quantification of dune crests and the defects and Y-junctions of these crests is both time intensive, subjective, and often applied only for small areas of dunefields [9,20,24]. Geocoding their location is difficult, with both existing computer and human-based approaches outputting results that are not completely reproducible [20].…”

Section: The Extraction and Characterization Problemmentioning

confidence: 99%

“…Ridges, the primary features in both dunefield and fingerprint feature spaces, are typically the only uniquely identifiable and bonified features in a field of poorly defined objects ( Figure 2) [20]. Other objects within these feature spaces are defined with reference to ridges.…”

Section: Introductionmentioning

confidence: 99%

Trace Evidence from Mars’ Past: Fingerprinting Transverse Aeolian Ridges

2019

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Linear dunes and human fingerprints share many characteristics. Both have ridges, valleys, and defects (minutiae) in the form of bifurcations and termination of ridgeline features. For dunes, determining how defects vary across linear and transverse dunefields is critical to understanding the physics of their formative processes and the physical forcing mechanisms that produce dunefields. Unfortunately, manual extraction of defect locations and higher order characteristics (type, orientation, and quality) from remotely sensed imagery is both time-consuming and inconsistent. This problem is further exacerbated when, in the case of imagery from sensors in orbit around Mars, we are unable to field check interpretations. In this research, we apply a novel technique for extracting defects from multiple imagery sources utilizing a robust and well-documented fingerprint minutiae detection and extraction software (MINDTCT: MINutiae DecTeCTion) developed by the National Institute of Standards and Technology (NIST). We apply our ‘fingerprinting’ approach to Transverse Aeolian Ridges (TARs), relict aeolian features commonly seen on the surface of Mars, whose depositional and formative processes are poorly understood. Our algorithmic approach demonstrates that automating the rapid extraction of defects from orbitally-derived high-resolution imagery of Mars is feasible and produces maps that allow the quantification and analysis of these features.

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Application of Database Approaches to the Study of Earth’s Aeolian Environments: Community Needs and Goals

Cited by 14 publications

References 196 publications

Migration and Morphology of Asymmetric Barchans in the Central Hexi Corridor of Northwest China

Migration and Morphology of Asymmetric Barchans in the Central Hexi Corridor of Northwest China

Migration of barchan dunes in the western Quruq Desert, northwestern China

Trace Evidence from Mars’ Past: Fingerprinting Transverse Aeolian Ridges

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