The use of new elevation data (SRTM/ASTER) for the detection and morphometric quantification of Pleistocene megadunes (draa) in the eastern Sahara and the southern Namib

Bubenzer, Olaf; Bolten, Andreas

doi:10.1016/j.geomorph.2008.05.003

Cited by 80 publications

(38 citation statements)

References 37 publications

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“…In the past decade the general availability of SRTM and ASTER GDEM versions provided public domain digital height datasets 2 for a growing number of earth science studies (Bolch, T. et al 2005;Bubenzer, O. and Bolten, A. 2008;Drăgu , L. and Eisank, C. 2012;Gichamo, T.Z.…”

Section: Introductionmentioning

confidence: 99%

An evaluation of EU-DEM in comparison with ASTER GDEM, SRTM and contour-based DEMs over the Eastern Mecsek Mountains

2014

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The availability of global coverage digital surface models (DSMs, like ASTER GDEM or SRTM) and the variation of fused models based on these (like EU-DEM) still has a great impact on scientifi c researches, as they provide a fairly good base dataset with a low production time and expenses. However, validation reports of the initial DSMs convinced different characteristics and errors, thus it is essential to examine these height datasets prior to application. A verifying process for EU-DEM is more important, because it has been published without a formal validation. Although the base of the EU-DEM was a corrected ASTER GDEM dataset, the visual assessment and the error statistics suggest more similarity to the SRTM DSM. This study goes further than just identifying the errors, it att empts to correct the height diff erences. For this reason altering the false values of the land cover and fi ltering the occurring noise was implemented. The geomorphometric analyses carried out as part of the verifi cation methods propose each improved model as potential base for geomorphological studies, if they meet the certain eff ective resolution requirements.

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Section: Introductionmentioning

confidence: 99%

An evaluation of EU-DEM in comparison with ASTER GDEM, SRTM and contour-based DEMs over the Eastern Mecsek Mountains

2014

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“…Although it has been found useful in the study of large aeolian landforms (Bubenzer and Bolten, 2008;Hayakawa et al, 2008;Hugenholtz and Barchyn, 2010), Reuter et al (2009) note that the GDEM product should not be used in terrain analysis at a 30 m resolution, and Miliaresis and Paraschou (2011) stress the importance of the number of scenes (stack number) used to derive the DEMs, and how vertical accuracy could be elevation-and slope-dependent. In our case, ASTER GDEM data for the Garopaba dune field proved to be consistently above the reference topography, resulting in a deviation of more than 35% from the reference data, which could be related to unresolved issues in the GDEM processing chain.…”

Section: Discussionmentioning

confidence: 99%

Influence of cell size on volume calculation using digital terrain models: A case of coastal dune fields

Grohmann

Sawakuchi

2013

Geomorphology

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In this work, we analyze how variation in cell size influences the volume calculated from Digital Terrain Models (DTMs) derived from a LiDAR (Light Detection and Ranging) survey in two coastal Late Holocene dune fields in southern Brazil. Cell size varied from 1 to 100 m. The RMSE (Root Mean Square Error) of the resampled DTMs from the original LiDAR (with 0.5 m resolution) increases linearly with cell size, while the R-squared decreases following a secondorder trend. The volume does not show simple linear or exponential behavior, but fluctuates with positive and negative deviations from the original DTM. This fluctuation can be explained by a random factor in the position of the cell with regard to landforms and a relationship between cell and landform size, wherein a small change in cell size can lead to an under-or overestimation of volume. ASTER GDEM (Global Digital Elevation Model) and X-SAR SRTM (Shuttle Radar Topography Mission) 1 arcsec Digital Elevation Models (DEMs) were not considered viable volume sources due to large deviations from the reference data, either as a consequence of noise in the SRTM X-SAR data or lack of bias elevation correction to a common reference base in the GDEM processing chain. Volumes from a 3-arcsec SIR-C SRTM deviated around ± 5% from the reference data and are considered suitable input for numerical simulations of Quaternary dune field evolution models because these values should be within the expected range of sediment volume changes over hundreds to millions of years.

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“…The Landsat Thematic Mapper (TM) and the Enhanced Thematic Mapper (ETM+) were also examined to understand the movement of the dunes (Parker 1999, Wang et al 2007). The capabilities of ASTER, Quick bird and Lidar images have been tested to study sand source, transport, and pathways, morphology and migration of sand dunes (Bourke et al 2009;Bubenzer and Bolten 2008;Bullard et al 2011, Hesse 2009, Hugenholtz and Barchyn, 2010Vermeesch, and Drake 2008). Multi-temporal Landsat TM images have been also explored to analyze dune dynamics at the dune-field scale (Ihab and Verstraeten 2012).…”

Section: Introductionmentioning

confidence: 99%

Automatic Extraction of Dunes From Google Earth Images New Approach to Study the Dunes Migration in the Laâyoune City of Morocco

Dakir

Rhinane

Saddiqi

et al. 2016

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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ABSTRACT:In desert environments, the sandy dune movements are considered as the main threat to the livelihoods and productivity of people living in Laâyoune city, South of Morocco. Studying dunes at a large scale requires intensive fieldwork and a huge dataset. But this task is not always easy because of the high cost and the limited availability of data. In this paper we present a new approach to study and evaluate the dune dynamic using Google earth archive image acquired from 2005, 2011, 2012, and 2013. To achieve this goal, an area with 3577 meter square including 40 barchan dunes, were selected, and the barchan dunes were automatically extracted from these images using Geographic Information System (GIS) and spatial analysis techniques provided by image processing software. The result shows not only the dune shape but also direction of dunes movements, and distance separating dunes. The obtained direction is ranging from North east to South west. The average rate of movement of the extracted dunes between 2005 and 2013 was calculated and is estimated at 32m per year. Validation of these dunes movement of the Laâyoune city was confirmed by the field data and previous studies.

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The use of new elevation data (SRTM/ASTER) for the detection and morphometric quantification of Pleistocene megadunes (draa) in the eastern Sahara and the southern Namib

Cited by 80 publications

References 37 publications

An evaluation of EU-DEM in comparison with ASTER GDEM, SRTM and contour-based DEMs over the Eastern Mecsek Mountains

An evaluation of EU-DEM in comparison with ASTER GDEM, SRTM and contour-based DEMs over the Eastern Mecsek Mountains

Influence of cell size on volume calculation using digital terrain models: A case of coastal dune fields

Automatic Extraction of Dunes From Google Earth Images New Approach to Study the Dunes Migration in the Laâyoune City of Morocco

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