Rainfall Warning of Creeping Landslide in Yunyang County of Three Gorges Reservoir Region Based on Displacement Ratio Model

Establishing the efficient and reasonable regional landslide hazards rainfall warning model plays an important role in landslide prevention. However, more previous studies have been focused on the early warning before sliding rather than on the temporary accelerated deformation of creeping landslide after the heavy rainfall. Taking landslides in Yunyang County of the Three Gorges Reservoir region as an example, statistical samples were selected reasonably according to the characteristics of the landslide surface displacement monitoring data firstly. Then the rainfall statistical variable applied to different time periods was determined by correlation analysis between rainfall index and landslide occurrence, and numerical simulation of displacement change of landslides in the rainfall condition. The displacement ratio (ratio of cumulative displacement and length of landslide) considering the scale characteristic of landslide was selected as the landslide deformation index and monitoring data of landslides and historical rainfall information in different time periods were counted. The relationship between daily rainfall data and monthly displacement data was built up. The displacement ratio model which can determine the rainfall thresholds was obtained, and fivelevel warning partition of creeping landslides in Yunyang County was determined. Finally, landslide instances, long-time displacement monitoring data and extreme rainfall event in research area were used to test the warning results of this model, respectively. The results show that the warning results of this model based on monitoring system data were the same as real conditions, and it could provide the basis for the early warning and prediction of the creeping landslides.