Abstract:
Abstract: Landslides, as one of the most prevalent geological hazards in China, are widely distributed and have also extended into the western regions. The Qinghai area is characterized by complex geomorphic units and clustered mountain systems, which provide favorable geological conditions for the initiation and development of landslides.【Objective】A comprehensive investigation into the formation mechanisms and controlling factors of representative landslides in this region can offer essential theoretical support for landslide prevention, mitigation, and hazard forecasting, thereby reducing casualties and economic losses.【Method】This study focuses on the accumulation landslide group of Hanjiacun, Qutan Town, Ledu District, Qinghai Province. Based on field investigations and monitoring data, the macroscopic deformation characteristics and formation mechanisms of the landslide group are systematically analyzed. Furthermore, the correlation between rainfall, temperature, and the deformation time series is examined using wavelet analysis. Rainfall and temperature were selected as the principal external variables. A linear regression ensemble model was employed, in which the predicted displacements from individual models were combined through a weighted summation approach to estimate the displacement at the GNSS2 monitoring station of the landslide. 【Result】The results indicate that the Hanjiacun landslide group exhibits an average annual deformation rate of approximately 8.5 mm, classifying it as a typical creep-type landslide. Its displacement demonstrates a step-like deformation pattern under the influence of both rainfall and temperature. The deformation prediction results of the Hanjiacun landslide group, derived from the multiple linear regression ensemble model, achieve a goodness-of-fit (R2) of 0.990, demonstrating high accuracy in reproducing the observed displacement patterns. 【Conclusion】Specifically, rainfall shows a positive correlation with cumulative displacement, with abrupt increases observed during periods of concentrated summer rainfall, followed by stabilization after the rainy season, while a lag effect is also evident. Temperature, in contrast, is negatively correlated with cumulative displacement. As temperatures decrease in winter, frost heave is induced by the freezing and volumetric expansion of pore water within the soil matrix of the slope, resulting in an increase in landslide deformation. With the onset of spring, thaw settlement gives rise to a rebound phenomenon in the accumulation layer.
Keywords: accumulation landslide; influencing factors; Wavelet analysis; landslide prediction model; multivariable linear regression.