关键词: 动态年周期, 相对时段速率, 水位年变异常, 中短期预测

Abstract: In recent years, more and more attention has been paid to the anomaly of annual well level variation and its implication to mid-term and short-term earthquake prediction. However, the qualitative comparison of dynamic pattern of the anomaly of annual well level variation displays an obvious uncertainty. To solve this problem, the random process and time series analysis techniques from probability theory and mathematical statistics are used to establish "the method of dynamic annual period" and "the method of comparative rate at comparative periods" for quantitative analysis of the anomalies of annual dynamic variation of well water levels. These methods are applied to the analysis of the observation data since 1985 till now from 21 wells of Tianjin well networks. The result has proved the feasibility and effectiveness of these methods for earthquake prediction. The analysis results demonstrate that the anomalies of well level occurred 17 times in 7 wells of Tianjin network one months and a half to six months before the occurrence of 4 moderate-strong (M_S≥5.8) earthquakes in this region. This fact may indicate again the applicability of the anomaly of annual well level variation to mid-term and short-term earthquake prediction.

Key words: dynamic annual period, comparative period velocity, anomaly of annual water level variation, mid-term and short-term prediction