Triggering conditions and mobility of debris flows associated to complex earthflows

Results show that clayey earthflow can transform under 5-year return period rainfall conditions into 1-km runout debris flow of volumes ranging between 2000 to 5000 m3. Slope failures induced by 25-year return period rainfall can trigger large debris flow events (30,000 to 50,000 m3) that can reach the alluvial fan and cause damage.