| Abstract/Description or Keywords |
Debris sliding is one of the most important processes acting to transport sediment within mountainous regions. Detailed study of debris slide activity at the basin scale typically involves landslide inventories generated from aerial photographs. However, it has been shown that some types of rapid mass movement can be accurately identified using a combination of high-resolution satellite imagery and digital elevation data. This approach is beneficial as the digital products allow for a more accurate and efficient data throughput into various types of geomorphic analysis. Here, we demonstrate the use of an automated inventory in the geomorphometric evaluation of debris slide initiation for the Chilliwack Basin, British Columbia, Canada. Our results indicate that the occurrence of debris sliding is primarily determined by topographical controls. For basins that are in equilibrium with the existing climate, the frequency of debris sliding should demonstrate a strong relationship to bedrock geology as the production of unconsolidated materials available for failure is a function of weathering rates under these conditions. The lack of bedrock control within the Chilliwack Basin suggests a state of paraglacial relaxation, wherein glacial deposits dominate the sediment cascade within the area. Therefore, topographic parameters can be used to discriminate the location of metastable slopes where debris slide erosion will be active. The use of digital data in the characterization of debris slide occurrence would seem to be a viable alternative to the more traditional methods. |
