THE MECHANISM OF SHALLOW LAYERS ANOMALY CAUSED BY GROUNDWATER AND ITS RELATED QUESTION IN EARTHQUAKE PREDICTION(2)

the problems in explanation of shallow layer anomalies with current seisimic precursor model (including material effusive model)are analyzed.Precursory anomalies have close relation with environmental factors in cause of formation.Induced precursory anomalies have 7 main features, i.e.diversity of types, the nonlinearity correlating with the change of rain and groudwater, the periodicity and seasonal feature of occurrence, hierarchical feature of variation, tussocky feature in temporal distribution, broad area in spatial distribution and the relevance of different kind anomalies.