Integrated detection of reservoir leakage channels based on synergistic geophysical-robotic-tracer technology

The upper reservoir dam of a pumped storage power station in Shandong Province, China, has experienced leakage. The maximum measured seepage flow on June 7, 2024, was 53.7 L/s. To accurately locate the leakage inlet, this study integrated flow field fitting, robotic inkjet inspection, and NaCl tracer testing. The experimental results show that the peak potential difference at the leakage point reached 0.28 mV, which is more than four times the background potential difference (approximately 0.06 mV). The injected ink will immediately form visible ink marks and move downstream. The tracer experiment showed that a distinct peak in conductivity occurred at the downstream monitoring point UPy-4, with a conductivity variation range of 400–440 µS/cm, and there was connectivity with the deployment point UPy-2. The results obtained from these three experimental methods all show obvious spatial correlations. This case study confirms that the multi-method approach combining flow field fitting, robotic inspection, and tracer testing enhances detection accuracy for complex leakage channels, enabling precise localization at the 8# panel joint on the right bank of the reservoir.