Details

Autor(en) / Beteiligte

• Reid, L.M. (USDA Forest Service Pacific Southwest Research Station, Arcata, CA.)

Titel

Calculation of average landslide frequency using climatic records

Ist Teil von

• Water resources research, 1998-04, Vol.34 (4), p.869-877

Ort / Verlag

Blackwell Publishing Ltd

Erscheinungsjahr

1998

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• Aerial photographs are used to develop a relationship between the number of debris slides generated during a hydrologic event and the size of the event, and the long-term average debris-slide frequency is calculated from climate records using the relation. For a site in California with an average of 8.3 slides km-2 yr-1, a sequence of four photo sets (representing 10-15 years, 35-50 observed slides, and 4-6 large storms) is needed to estimate the longterm debris-slide frequency to within 30% of the actual value (p = 0.90). If climatic records are used, a record length of 5-10 years (17-35 observed slides and 2-4 significant storms) is sufficient to provide the same accuracy. The climate-based model suggests that debris-slide frequency changed from approximately 1.6 to 8.3 slides km-2 yr-1 during the late 1930s owing to an increased frequency of high-intensity storms. The model accurately predicts the change in slide-scar density observed on sequential aerial photographs following the climatic shift