Study on the Acoustic Field Model and Operational Response of Noise from High Dam Flood Discharge

The noise produced by high dam flood discharge is prolonged and propagates over a great distance, significantly impacting the lives of nearby residents. However, accurately predicting and mitigating this noise remains challenging due to the complex nature of its sources and the lack of comprehensive models that are capable of deconstructing the overall sound field. This study systematically investigates the propagation characteristics and generation mechanisms of environmental noise from flood discharges at the Xiangjiaba Hydropower Station. A novel three-dimensional framework for classifying acoustic sources (point, line, and surface) is proposed. By integrating prototype observations with Strouhal-scaled hydraulic model tests, a multi-source sound field model was developed that employs a regression algorithm to quantify the power of individual sound sources based on holistic field measurements. The model achieves prediction accuracy within 1.5 dB when validated against prototype data. The results indicate that the rolling water surface in the stilling basin (surface source) is the dominant contributor to noise. A key quantitative finding is that, under identical discharge conditions, the noise intensity generated by surface spillways is three times greater than that produced by bottom spillways. Overall, this model serves as a critical tool for understanding acoustic characteristics and formulating noise-informed operational strategies.