Time-lapse CCR survey for a cost effective safety evaluation of river embankments

We have conducted the time lapse CCR survey to evaluate the safety of the river embankment, and obtained good quality data for four measurements including an initial survey and three monitoring surveys after a certain amount of rainfall. Regardless of the amount of rainfall, the calculated resistivity change rate sections help us to detect the permeable zone that must be monitored intentionally to prevent the seepage failure of the river embankment. Although the resolution of the CCR survey is lower than the normal ERT result, the result is sufficient enough to detect the permeable zone. The detected permeable zone is coincided with the past damaged zone by heavy rainfall; thus the applicability of the method is validated. Since the cost and survey time can be significantly reduced from the usual ERT, the time lapse CCR is considered as a cost effective safety evaluation method of the river embankments.