Aeolian Sand Transport

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Aeolian Sand Transport Sand can potentially help preserve archaeological features by direct burial and/or by mitigating gullying and other erosion. Sand can be deposited on archaeological features or within gullies via fluvial (river) or aeolian (wind) deposition. Most archaeological sites are above the highest contemporary river stage, so aeolian deposition is the most likely mechanism for preservation and/or erosion mitigation. River-sourced sand deposition is a time-dependent process, and the outer limit of that process may extend for many years after any individual HFE. Additionally, HFEs with targeted vegetation removal could produce a net sediment surplus at some sites. [1]

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Updates [2] [3] Of 358 river-corridor arch sites (RM 0-240), 74 (21%) are adjacent and upwind of sandbars receiving HFE sand (Type 1 and Type 2a) that don't have some sort of topographic barrier between the sandbar and the arch site. Of these, 43 sites are currently blocked by vegetation from receiving aeolian sand. [4]

Links Cultural Resources Page Sediment Page Questions Does aeolian sand transport research support the use of sand bar building from HFEs as a means to provide a source of aeolian sands to preserve and protect archaeological sites? Presentations and Papers 2017 Fluvial-aeolian sediment connectivity during the current HFE protocol: alteration on fluvial-aeolian sediment connectivity in Grand Canyon 2016 Collins et al. 2016. Relations between rainfall–runoff-induced erosion and aeolian deposition at archaeological sites in a semi-arid dam-controlled river corridor, Earth Surf. Process. Landforms East et. al. 2016. Conditions and processes affecting sand resources at archeological sites in the Colorado River corridor below Glen Canyon Dam, Arizona: U.S. Geological Survey Professional Paper Linkages between controlled floods, eddy sandbar dynamics, and riparian vegetation along the Colorado River in Marble Canyon, Arizona, USA 2015 Conditions and Processes affecting sand resources at archaeological sites 2014 Gully annealing by Aeolian sediment: Field and remote-sensing investigation in Glen, Marble, and Grand Canyons (Sankey) Other Stuff Collin et al. 2016: Aeolian deposition was found at 4 sites (30%) where partial infilling occurred preventing further erosion. “Despite this promise for archaeological site preservation, our observations show that gully annealing can only occur under a specific set of conditions related to fluvial sand availability and wind transport direction.” "In this study, aeolian deposition, even with anthropogenic forcing via fluvial sand-bar building high flow dam releases, was found to be generally insufficient to offset the effects of precipitation-induced gullying." East et al. 2016: The problem: Landscapes downstream from Glen Canyon Dam contain archaeological resources that are affected by fluvial (river), aeolian (wind), and hillslope (gravity and rainfall-runoff) geomorphic processes. The question: Can Colorado River sediment enhance the preservation of river corridor archaeological resources in these landscapes through aeolian sand deposition and mitigation of gully erosion? The results: Relatively few archeological sites are now ideally situated to receive aeolian sand supply from sandbars deposited by recent controlled floods (HFEs) from Glen Canyon Dam (decreased from 98 sites in 1973 to 32 in 2012).[5]