jgg     2014 34 (3):  48-51    ISSN: 0412-1961  CN: 21-1139/TG VARIATION CHARACTERISTICS OF EARTH ELECTRICAL PROPERTY BEFORE BADONG EARTHQUAKE AND FORMATING MECHANISM Earthquake Administration of Hubei Province，Wuhan 430071 Received: 2014-03-12  Revised: null  Online: 2014-05-28 Supporting info