WANG S, LI K, WANG Y L,et al.Correlation mechanism between phreatic line and reservoir water level observations in upstream-style tailings dams[J].Journal of Henan Polytechnic University(Natural Science) ,2025,44(6):36-44.

doi:10.16186/j.cnki.1673-9787.2025030069

Received: 2025/03/30

Revised: 2025/06/12

Published: 2025/10/14

Correlation mechanism between phreatic line and reservoir water level observations in upstream-style tailings dams

Wang Sha1,2, Li Kun1,2, Wang Yali1,2, Chu Yifan1,2, He Binbin1,2

1.Beijing General Research Institute of Mining & Metallurgy， Beijing  100160， China；2.National Center for International Joint Research on Green Metal Mining， Beijing  100160， China

Abstract: Objectives Due to fluctuations in reservoir water level， the phreatic line exhibits a certain correlation with water level observations. However， the underlying mechanism remains unclear.  Methods Prototype 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 water 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， calculate 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， its square， cube， 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.

Key words: phreatic line; reservoir water level; statistical regression model; grey correlation analysis; time effect