【摘要】 针对新疆呼图壁２１ 号泉地下水位动态特征，提出新的识别异常方法——日极差法。在分析天山中段５ 级地震和新疆境内大于６．０ 级地震前后２１ 号泉地下水位动态异常变化时，发现用日极差法消除水动态随机变化，突出、识别异常，效果显著。震例验证结果及地震预报效能评价证明：日极差法具有操作性能强，简便、快速、有效的特点。更多还原

【Abstract】 ln the light of the dynamic characteristics of groundwater level of Hutubi,Xinjiang,Spring No.21,a new anomaly recognizing method——daily extremum difference method is suggested. Using this method to analyze the dynamic variation of groundwater level of Spring No.21 before and after 5.0≤M S≤5.9 earthquakes in Middle Tianshan and M S≥6.0 earthquakes in Xinjiang,it is found that the method can eliminate the random variation of groundwater level behavior and make the anomalies outstanding very well.The test for prediction results of earthquake examples and the evaluation for prediction effects prove daily extremum difference method to be simple,speedy and easily operated.更多还原