AN INVESTIGATION OF ADIRONDACK DEBRIS FLOWS USING GIS

Debris flows are rapidly moving mixtures of water and debris that travel downslope under the force of gravity. The highpeaks region in the Adirondacks is prone to debris flows. The purpose of this study was to compare multiple debris flow scarps and the physical characteristics of the surrounding areas to delineate possible reasons for failure. Debris flows that occurred between 1995 and 2003 were studied using ArcMap and ArcScene (geographical information systems programs) to digitize, map, and measure the dimensions, slopes of the scarps left behind, amount of debris colluvium, and dominant vegetation found in the area of each debris flow. Precipitation records were also collected to inspect the relationship between times of high rainfall and slope failure. Three dimensional models were developed for individual failure planes to depict physical characteristics for comparison. The data that was collected in the field were observations of the type of soil, soil thickness, and measurements of soil strength. Loss on ignition tests were performed on collected samples to determine organic content. Field data and computer data will be studied together to produce a model of the characteristics needed for a soil failure in the Adirondack highpeaks region. Information on the region's slope stability limits will be useful in identifying areas that have potential as high risk for failure.