Abstract: The development of time-lapse prospecting technology is briefed through summarizing the methods of detecting hidden dangers of dykes. The working principle of time-lapse high-density resistivity method is expounded from aspects of observation mode, data acquisition and processing, inversion and image rendering, as well as anomaly judgment method. The effectiveness of time-lapse high-density resistivity method in detecting hidden dangers of dyke is examined by 3D forward simulation of two typical hidden dangers, namely, cave and leakage. Moreover, pilot demonstration of the techniques of time-lapse high-density resistivity method is presented based upon engineering practice. Furthermore, the possibility of time-lapse prospecting technology in dynamic detection of hidden dangers of dyke are evaluated in conditions of long distance of dyke and concealing, abrupt, lasting, and lowly detectable dangers.

Key words: hidden danger of dyke, time-lapse high-density resistivity method, inversion and image rendering, dynamic detection, 3D forward simulation