Abstract: Based on systematical investigation of present digital observation situation of well-water level, we have analyzed the yearly, monthly and daily dynamic behavior characteristics at different levels, and evaluated the monitoring efficiency of earthquake precursor on the basis of the earthquake cases. The result shows: (1) 90% of the wells, its' daily and monthly behaviors have some regularity, can exert its' efficiency in the medium-term precursory monitoring, (2) 50% of wells, its' daily and monthly behaviors have some regularity and have no step-change and impulse over trinal mean squared error, can exert its' efficiency during the short-term and short-impending-term precursory monitoring. The result also shows that there is impulse-type anomalies, affected exertion of earthquake monitoring efficiency severely, which accounts for about half of water level wells.

Key words: Well-water-level, Behavior characteristics, Monitoring efficiency, Beijing-Tianjin-Hebei region