Predicting delta avulsions: Implications for coastal wetland restoration
D.A. Edmonds et al., The Pennsylvania State University, Dept. of Geosciences, University Park, Pennsylvania 16802, USA. Pages 759-762.
Avulsions are the natural process by which flow is diverted out of an established river course and onto the adjacent floodplain. Avulsions are significant natural hazards because they produce extensive flooding as water is diverted over the floodplain. In other areas, like river deltas, avulsions are the natural process that constructs wetlands. Currently there is considerable interest in wetland restoration, especially in the Mississippi deltaic plain, where rapid disappearance of wetlands may have exacerbated damage caused by Hurricanes Katrina and Rita. Until now, the timing and location of avulsions has been notoriously difficult to predict. Using scaled-physical experiments of deltas at the Exxon Mobil Research Lab, Edmonds et al. determined that the avulsion location can be predicted by finding the location on the levee that has experienced the greatest stress for the longest period of time. For five different experimental deltas, they were able to predict the avulsion location with 93% accuracy. These results represent the first mechanistic understanding of avulsions that allows for accurate prediction of their location.
Mapping potentially asbestos-bearing rocks using imaging spectroscopy
G.A. Swayze et al., U.S. Geological Survey, Denver, Colorado 80225, USA. Pages 763-766.
Rock and soil that may contain naturally occurring asbestos (NOA), a known human carcinogen, were mapped in the Sierr
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