9527263 Rose Debris flows are hazardous when they occur. In the past such events have destroyed and damaged property and killed tens of thousands of people. This study will seek to improve the understanding of debris flows and hyperconcentrated flows through experiments, theoretical and modeling efforts, and study of deposits from experiments. This proposal is a part of a larger study plan consisting of three major parts: 1) small scale laboratory experiments in flumes 1 to 8 m long and 5 to 30 cm wide at McGill University; 2) large scale experiments in a flume 2 m wide and 95 m long at the U.S. Geological Survey flume in Oregon; 3) a field study of noncohesive debris-flow deposits. This proposal seeks funding for parts 1 and 2 of the plan. Part 1, small scale laboratory experiments, is supported, in part, by a Canada International Fellowship to the principal investigator from the National Science and Engineering Research Council of Canada. Experiments in small flumes have the advantage that setting up and finishing a large matrix of experiments in a short time is feasible and that steady uniform flow is easily attained, but they are drastically scaled down from the natural processes that they are meant to stimulate. In small flumes, data can more easily be collected, but some of the conclusions drawn from it may be suspect because of the difficulty in scaling large flows, especially those that contain large proportions of gravel sized debris. It is therefore critical to perform experiments in a large apparatus to determine the effects of scaling and to reproduce natural flow conditions and deposits more accurately.
