Rainfall Induced Debris Flow Series in Western Ghats of Indian Peninsula

摘要

Many factors such as hill slope, relative relief, attitude of joints, material properties of rocks, type of vegetation and landuse practices make a hill slope vulnerable to debris flow.During the monsoon period, slope failures are a common natural disaster in the Western Ghats lying in the southern part of Indian peninsula.Its ferocity depends upon the material properties and thickness of the loose unconsolidated overburden formed by the weathering process.The triggering factor for the debrisflow is found to be continuous heavy rainfall for a couple of days.The paper examines the influence of shift in rainfall pattern and its variation on debris flow events.The failure surface is identified and located from the field and its interaction with material properties and hill slope is critically examined.Highly weathered rock samples were collected from the failed areas for the determination of material property such as friction angle.Geometrical method is used for understanding the role of joints in the slope instability.