Regional aeolian dynamics and sand mixing in the Gran Desierto: Evidence from Landsat thematic mapper images

Journal Article · Mon Sep 10 00:00:00 EDT 1990 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JB095iB10p15463· OSTI ID:5932993

Blount, G; Greeley, R; Christensen, P R ^[1]; Smith, M O; Adams, J B ^[2]

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1. Arizona State Univ., Tempe (USA)
2. Univ. of Washington, Seattle (USA)

Spatial variations in sand composition were mapped on a regional scale in a terrestrial sand sea, the Gran Desierto of Sonora, Mexico. Mesoscale mapping on a satellite image base allowed quantitative interpretation of the dynamic development of sand sheets and dunes. The results were used to interpret the Quaternary geologic history of the tectonically active region at the mouth of the Colorado River. Landsat thematic mapper multispectral images were used to predict the abundance of different mineralogies of sand grains in a mixed aeolian terrain. A spectral mixing model separated the effects of vegetation and topographically induced shading and shadow from the effects produced by different mineral and rock types. Compositions determined remotely agreed well with samples from selected areas within the spectral limitations of the thematic mapper. A simple discrimination capability for active versus inactive sand surfaces is demonstrated based upon differences in the percentage of low-albedo accessory grains occurring on dormant aeolian surfaces. A technique for discriminating between low-albedo materials and macroscopic shade is implemented by combing thermal images with the results of the spectral mixing model. The image analysis revealed important compositional variations over large areas that were not readily apparent in the field.

• OSTI ID: 5932993
• Journal Information: Journal of Geophysical Research; (USA), Vol. 95:B10; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
DESERTS
MAPPING
MEXICO
COLORADO RIVER
DEPOSITION
DUNES
EARTH PLANET
ENVIRONMENTAL TRANSPORT
EROSION
GEOCHEMISTRY
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC MODELS
IMAGES
LANDSAT SATELLITES
MARS PLANET
MINERALOGY
QUATERNARY PERIOD
REGIONAL ANALYSIS
REMOTE SENSING
SAND
VENUS PLANET
WIND
ARID LANDS
CENOZOIC ERA
CHEMISTRY
DEVELOPING COUNTRIES
GEOLOGIC AGES
LATIN AMERICA
MASS TRANSFER
NORTH AMERICA
PLANETS
RIVERS
SATELLITES
STREAMS
SURFACE WATERS
580000* - Geosciences