Sand movement patterns in the Western Desert of Egypt: an environmental concern

Hereher, Mohamed E.

doi:10.1007/s12665-009-0102-9

Cited by 59 publications

(19 citation statements)

References 15 publications

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“…These areas have distinctive features in different types of purple or ochreous sand dunes accompanied with strips or ripples in the direction of prevailing wind. Considering the difficulty of texture recognition for supervised classification or unsupervised classification, visual interpretation combining geography, climate, SDS paths on MODIS images and knowledge from previous studies were considered as reference to identify SDS source areas (Al-Hurban and Al-Ostad, 2009;Furman, 2003;Hereher, 2009;Li et al, 2013;WMO, 2013). After mapping out SDS source areas in Syria and Iraq, the SDS situation in other three pilot countries were generated using the interpretation experience consequently.…”

Section: Methodsmentioning

confidence: 99%

Identification of dust storm source areas in West Asia using multiple environmental datasets

Cao

Amiraslani

Liu³

et al. 2015

Science of The Total Environment

146

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Section: Methodsmentioning

confidence: 99%

Identification of dust storm source areas in West Asia using multiple environmental datasets

Cao

Amiraslani

Liu³

et al. 2015

Science of The Total Environment

146

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“…The dune migration was measured using Google Earth historical satellite images, which was widely used to investigate the dune changes [16][17][18][19] The images were extracted using ArcGIS software (Esri, Redlands, CA, USA). This step was performed by locating two control lines of the known coordinates in the Google Earth image, which were saved as a shape file, and a layer of the reference points in the ArcGIS database.…”

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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“…The wind regime of a region is the main force responsible for the dune field pattern. Wind energy environment (the wind's drift potential (DP) and directional variability (RDP/DP, where RDP is the resultant drift potential)), which calculates an index of sand transport intensity, has also been applied in studies of dune patterns around the world (Fryberger and Dean, 1979;Bullard et al, 1996;Hereher, 2010). The methods developed in these prior studies have been used subsequently to examine possible regional-scale changes in dune morphology to understand changes in regional wind regimes (e.g.…”

Section: Introductionmentioning

confidence: 99%

Wind regimes and aeolian geomorphology in the western and southwestern Tengger Desert, NW China

et al. 2014

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Wind is the primary control on the formation of aeolian geomorphology. In this study, we combined wind regime data from automated weather stations in the western and southwestern Tengger Desert of the Inner Mongolia region in China with remote‐sensing data to analyse the relationship between the wind energy environment and aeolian geomorphology. Tengger Desert is one of the main dust storm sources in northwestern China. Therefore, efforts aimed at controlling desertification and dust storm require a deeper understanding of the processes that govern the formation and subsequent evolution of dunes in this area. Wind speed was largest in the northwest (3.3 m/s in the Xiqu station) and smallest in the southeast (1.2 m/s in the Haizitan station). Potential sand transport was also largest in the northwest (195 in the Jiahe station) and smallest in the southeast (33 in the Tumen station). The sand‐driving wind (5.92 m/s) directions were from the NW and SE quadrant across the study area, at >76% of all sand‐driving wind, reaching 99% in the Tumen station. The sand‐driving wind in the NW quadrant reached >48%, and in the SE quadrant, >12% of all sand‐driving wind in all stations. In the study area, sand dunes included crescent, dune networks, transverse, and coppice dunes. Dune crest directions had similar trends from upwind to downwind, at 133° in the middle region, and 124° in the southwestern region. Mean dune spacing changed with dune patterns; the maximum spacing for crescent dunes was 147 m, for dune networks 118 m, and for transverse dunes it was 77 m. The mean crest length was 124 m (maximum) for crescent dunes in the northwest, 121 m for transverse dunes, and 84 m for dune networks. However, because of gullies in the southern region, the mean crest length was only 58 m (least) for the crescent dunes in that area. The defect density ranged from 0.007 to 0.014. The spatial differences in dune patterns reflected the evolution of the dune field, where older dunes had been formed upwind and younger downwind. Copyright © 2014 John Wiley & Sons, Ltd.

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Sand movement patterns in the Western Desert of Egypt: an environmental concern

Cited by 59 publications

References 15 publications

Identification of dust storm source areas in West Asia using multiple environmental datasets

Identification of dust storm source areas in West Asia using multiple environmental datasets

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

Wind regimes and aeolian geomorphology in the western and southwestern Tengger Desert, NW China

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