Shallow groundwater flow characteristics are crucial for slope stability assessments and hydrological interactions in floodplains. However, shallow groundwater flow paths exhibit high spatial heterogeneity, and conventional monitoring methods are limited by their point-scale representativeness or detection accuracy, which hinders the characterization of path distribution. This study used the groundwater aeration sound method to investigate shallow groundwater flow in a slope and a floodplain. Artificial sprinkling tests were conducted to examine instrument performance and limitations. The results confirmed that flow sound intensity decayed as a power function with distance,with an effective detection range of approximately 1.5–2.0 m. In the improved analytical workflow, environmental noise was filtered out through sound characteristic identification, and groundwater flow patterns were interpreted through sound acceleration intensity and aeration event frequency. Field surveys revealed that in the slope site,groundwater not only converged at the toe because of gravity but also flowed through preferential paths in the middle slope. In the floodplain site, high-intensity continuous flow sounds were detected in the riparian zone, indicating substantial river water flow, while the area near the slope exhibited low-intensity, high-frequency signals, reflecting groundwater recharge from the slope. Overall, this study demonstrates that the groundwater aeration sound method is nondestructive and easy to apply. This method enables the effective and rapid identification of potential shallow groundwater locations and flow patterns and the determination of possible groundwater sources.
Key Words: Groundwater aeration sound, shallow groundwater, preferential flow, slope, floodplain.