A rapid loess flowslide triggered by irrigation in China

A loess landslide occurred in the morning of October 6, 2006, in Gaolou district of Daming town, Hua country, Shaanxi, China. The landslide originated from a valley side slope of the loess ‘yuan’ (dissected loess plateau), below which many houses are densely located. The displaced materials smashed several houses and killed 12 persons, after traveling down a long but gentle valley channel. Field surveys revealed that the displaced materials were highly fluidized. Because there was no rainfall before this event, the leakage of irrigation water from the canal on the top of the slope may be the reason for the initiation. To investigate the possible mechanisms underlying the initiation and movement of this landslide, laboratory tests on the loess samples from the source area were performed. Some preliminary research results are presented in this report.     

Zoning for flowslide and debris flow in pyroclastic soils of Campania Region based on “infinite slope” analysis

Campania Region (Italy), one of the most densely populated areas in Europe, is probably the one with the highest risk of landslide. A large part of the region is covered by unsaturated cohesionless pyroclastic deposits subjected to rainfall-induced landslides. According to experience, these can display different features and magnitude. The most catastrophic landslides are liquefied debris flows which periodically occur on steep slopes, causing death and destruction in areas located downslope. Therefore, zoning of those areas which can be the source of liquefied debris flow is necessary. The paper reports some useful elements for zoning based on infinite slope analysis, accounting for the results of recent research on the mechanics of rainfall-induced landslides in pyroclastic soils.