Early Warning of Abrupt Displacement Change at the Yemaomian Landslide of the Three Gorge Region, China

Abstract

Like most natural systems, landslides also have critical points at which a great change in displacement occurs. The displacement may recover increasingly slowly from small perturbations when landslides approach an abrupt change. The Yemaomian Landslide, located in the Three Gorge Region, China, is studied. A time series of displacement is modeled using an autoregressive (AR) model and a detrended fluctuation analysis (DFA) method. The coefficient and variance of AR(1) and the scaling exponent of DFA are estimated using a slide window. The results show that the DFA scaling exponent can indicate the abrupt change in displacement. The DFA scaling exponent increases when an abrupt change is approaching. If the variation in displacements is small, the scaling exponent declines accordingly. The variance of AR(1) may also indicate the displacement fluctuation. These early-warning signals are extracted directly from the observations. They can be used to detect abrupt changes in real time series. They have the potential to be used as early-warning signals for a wide range of landslides.