The Research Of Quantitative Analysis Of The Correlation On Deformation Of Baijiabao Landslide Between Rainfall And Water Level

The data show that about 90% of landslides instability are closely related to water.The important factors inducing the instability of the reservoir bank slope are rainfall and the fluctuation of reservoir water level.After the impoundment of the Three Gorges reservoir area,geological disasters such as landslides and collapses have occurred frequently.In the Three Gorges reservoir area,the periodic fluctuation of the reservoir water level superimposes the continuous rainfall or heavy rainfall makes the stress field of the bank slope and the groundwater seepage field change significantly,threatening the stability of the slope which widely distributed on both banks of the reservoir.The Baijiabao landslide is a representative of step-type deformation landslide with hysteresis.This paper takes the Baijiabao landslide in the Three Gorges Reservoir area as the research object,combines the water level dispatching data,hydrometeorological data and landslide exploration data of the Three Gorges Reservoir to analyze the deformation characteristics and mechanism of the Baijiabao landslide and the relationship between landslide deformation and rainfall and reservoir water level.Degree of analysis and research.The main work and conclusion includes:1)The geological features such as landform,material composition,structural characteristics,hydrogeology and geological structure of Baijiabao landslide are Explained.The deformation of Baijiabao landslide is mainly affected by the rapid decline of reservoir water level in qualitative analysis.2)Based on the professional monitoring data of Baijiabao landslide,the Pearson correlation coefficient method is used to analyze and calculate the correlation in the deformation,reservoir water level and rainfall.The reservoir water level drops rapidly during the period from May to June.The simple correlation coefficients of deformation at each point and reservoir water level is about-0.75;landslide deformation and rainfall from May to June each year the correlation coefficients is about 0.45.There is low degree of correlation or substantially irrelevant during the period from January to April and July to December each year among the deformation of the landslide rainfall and reservoir water level.3)In order to further eliminate the interaction among the three variables of landslide— deformation,rainfall and reservoir water level fluctuation,the net correlation analysis method is used to analyze again.When the correlation between landslide deformation and rainfall is about to calculated,the reservoir water level fluctuation value is taken as a control variable,when the correlation between landslide deformation and reservoir water level fluctuation is about to calculated,rainfall is taken as the control variable.The calculation results show that the net correlation coefficient between landslide deformation and reservoir water level fluctuation from May to June is about-0.74,while the net correlation coefficients between landslide deformation and rainfall is about 0.46,and in other periods of time,there is low degree or substantially irrelevant of correlation among landslide deformation rainfall and reservoir water level.4)According to the results calculated by Pearson correlation coefficient method and net correlation coefficient method,it suggest that the correlation between the deformation of the Baijiabao landslide and the reservoir water level is significantly greater than the correlation between landslide deformation and rainfall,especially during the rapid decline of the reservoir water level from May to June each year,there is a positive correlation between the deformation of the landslide and the rapid decline of the reservoir water level,the faster the reservoir water level drops,the greater the deformation of the landslide,and the highest sensitivity of the landslide deformation affected by the reservoir water level of 145 m.