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Estimation of erosion, deposition, and net volumetric change caused by the 1996 Skeiðarársandur jökulhlaup, Iceland, from Synthetic Aperture Radar Interferometry
Author(s) -
Smith Laurence C.,
Alsdorf Douglas E.,
Magilligan Francis J.,
Gomez Basil,
Mertes Leal A. K.,
Smith Norman D.,
Garvin James B.
Publication year - 2000
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/1999wr900335
Subject(s) - digital elevation model , elevation (ballistics) , deposition (geology) , geology , synthetic aperture radar , interferometric synthetic aperture radar , erosion , backscatter (email) , glacier , remote sensing , interferometry , fluvial , interpolation (computer graphics) , snow , radar , geomorphology , sediment , hydrology (agriculture) , computer science , geotechnical engineering , structural basin , astronomy , animation , telecommunications , physics , geometry , mathematics , computer graphics (images) , wireless
Using repeat‐pass satellite synthetic aperture radar interferometry, we develop a methodology to measure flood‐induced erosion and deposition and apply it to a record 1996 glacier outburst flood (jökulhlaup) on Skeiðarársandur, Iceland. The procedures include (1) coregistration of backscatter intensity images to observe morphological differences; (2) mapping of interferometric phase correlation to identify preserved and modified surfaces; and (3) construction, correction, and differencing of pre‐jökulhlaup and post‐jökulhlaup topography. Procedures 1 and 2 are robust and should be widely applicable to other fluvial environments, while procedure 3 is complicated by uncertainties in phase measurement, baseline estimate, and atmospheric effects. After a correction procedure involving interpolation of digital elevation model elevation differences across low‐correlation areas, we find ∼4 m of elevation change are required to calculate volumes of erosion or deposition. This condition was satisfied for the 40 km 2 proglacial zone of Skeiðarársandur, where we estimate +38×10 6 m 3 of net sediment deposition along the ice margin, −2 ×10 6 m 3 of net erosion in channels downstream, and a total net balance of +13 × 10 6 . These estimates are supported by field observations and survey data collected in 1997.