An Attempt to Quantify the Lag Time of Hydrodynamic Action Based on the Long-Term Monitoring of a Typical Landslide, Three Gorges, China

Hydrodynamic action plays an important role in the development of reservoir bank accumulational landslides. Despite recent concern over hydrodynamic action’s hysteresis effects, there is still no unified efficient method for quantifying lag time, which is a critical input to landslide prediction and early warning systems. To address this shortcoming, we selected a typical landslide, located in Three Gorges Reservoir, China, as a case study. On the basis of long-term monitoring data, we suggest that correlation analysis may work and attempt to use linear correlation first to quantify the lag time. We conclude that, from the macroscopic behavior point of view, linear correlation analysis does not work; neither the daily reservoir water level and its variation nor the daily rainfall and its accumulation exhibit a linear relationship with the surface accumulative displacement. Future studies will use nonlinear correlation analysis to analyze data by different time segments as the hydrodynamic factors have different effects in different periods.