The paper is to detect the leakage inlets, determine the leakage
pathways through the dam, and ensure that the amount of the leakage in
the upstream and downstream is consistent, and that there is no leakage
around the concrete face rockfill dam. The injection of a pseudo-random
current in the water between two aluminum sheets A and B generates a
current field that can be measured in the water with sensitive current
sensors. When the current is channeled along leakage pathways, the
flow-field fitting method can be used to detect these inlets of the
leakage pathways. We first review the background equations for the
seepage field and the current field in the flow-field fitting method,
and we also use an approach to calculate the discharge and ensure the
consistency of the upstream and downstream leakage based on the Doppler
effect in physics. Moreover, to illustrate how the flow-field fitting
method works, we use numerical simulation method to verify the
feasibility of the flow-field fitting method. Lastly, we proceed with a
case study for which the flow-field fitting method and the acoustic
Doppler flow velocity measurement are used to identify and map potential
leakage pathways bypassing upstream into the flow measurement weir of
the downstream. The approaches proposed in this paper successfully
detect three leakage areas and obtain the discharge. The results of
detected in a case study provide engineering geology information for
optimizing the layout of grouting holes.