【摘要】 研究了华北地区６级左右强震前水氡观测值异常的时空非均匀分布变化特征。结果表明，在强震前水氡观测异常台站的空间分布非均匀性发生显著变化，Ｃｖ值有明显的升高过程。这说明，强震前短临地震前兆异常空间分布的非均匀性增强，变得更加不均匀，这可能反映了地壳应力场的增强过程。更多还原

【Abstract】 The characteristics of variation in inhomogeneity of temporal-spatial distribution of stations with Radon anomaly observed before strong earthquakes with magnitude of about 6 occurred in North China are Investigated. To describe the inhomogeneity of tem- poral-spatial distribution of observational station, showing Radon anomaly, Cv value is employed. The results show that the Cv value distribution of short-term and imminent pre- cursors increases and becomes more inhomogeneous before the strong earthquakes, which could reflect the enhancement of the crustal stresses.更多还原