Correlation mechanism between phreatic line and reservoir water level observations in upstream-style tailings dams
Wang Sha
Li Kun
Wang Yali
Chu Yifan
He Binbin
Abstract：Objectives Due to fluctuations in reservoir water level,the phreatic line exhibits a certain corre-lation with water level observations.However,the underlying mechanism remains unclear.Methods Proto-type observation data of the phreatic line and reservoir water level from a typical upstream tailings dam were collected.Statistical regression models were established to analyze their relationships with absolute wa-ter level,hydraulic head,and time effect,with goodness-of-fit used to assess model performance.Based on these models,grey correlation analysis was applied to compare the importance of different factors,calcu-late correlation coefficients,and rank their significance,thereby identifying the key factors influencing the phreatic line.Results The spatial variation trends of the constructed factors showed strong dependence on the dependent variable.Phreatic line observations were significantly correlated with the measured hydraulic head(H),its square(H²),cube(H³),as well as the average head and head rise rate over the previous 5～30 days.The regression results demonstrated high accuracy.Conclusions Regression performance varied across monitoring positions,but consistently showed correlations with hydraulic head and its rate of change,along with some dependence on time effect.This correlation with time weakened as the observation period lengthened.
Keywords：phreatic linereservoir water levelstatistical regression modelgrey correlation analysistime effect
Publication Date：2025-11-30
Online Publishing Date：2025-10-22(First online date of this platform, not the publication date of the document)
Pages：9( 36-44 )