A STUDY OF DIFFERENCE EVOLUTION IMAGE OF WATER HEAD GRADIENT VARIATION AND A PREDICTION METHOD FOR STRONGEARTHQUAKE RISK REGIONS

Based on the analogue to the calculation method of ground temperature gradient,the pressure water head height of one meter well depth or one hundred meter well depth,which are grouped from the water level buried depths of a lot of wells in regional ground fluid pressure fields,is defined as water head gradient value.By scaning the time,space and strength of difference values of water head gradient variation,the dynamic evolution image can be drawn and then the potential risk regions of future strong earthquakes can be predicted.The test result for the Tangshan M 7.8 earthquake is relatively ideal.