INTEGRATION OF REMOTE SENSING AND FIELD DATA FOR ASSESSING LANDSLIDE HAZARDS AFTER WILDFIRES IN CENTRAL IDAHO

This study explores the use of remote sensing imagery in understanding the mechanisms of debris flows and sediment transport after the summer 2000 wildfires in central Idaho. The project includes collecting ground-based field data and acquiring satellite imagery for a field site in the Yellowjacket Creek drainage of Salmon-Challis National Forest, Idaho. Field data observations were collected in summer 2001 and 2002 and include bedrock geology, geomorphology, topography, burn degree, soils, and vegetation. High resolution IKONOS multispectral and medium resolution RADARSAT synthetic aperture radar (SAR) imagery were acquired in 2001.

The IKONOS imagery provides detailed vegetation and burn degree information to help in identifying areas that may be susceptible to debris flows and sediment transport. The RADARSAT imagery has been used experimentally for creation of medium resolution digital elevation models (DEMs) to characterize the topography of the burned areas. The creation of higher resolution DEMs from RADARSAT imagery will be experimented with and compared to USGS DEMs to assess their utility in understanding the geomorphology of rugged landscapes.

A geographic information system (GIS) is used to compile the field and imagery data. The study ultimately aims to develop a relative risk assessment map of landslide susceptibility and to evaluate controlling risk factors with the use of the GIS data.