Leak-acoustic attenuation in water pipelines: distributed and local losses

The graphical abstract provides a brief overview of the primary work conducted in this study. It illustrates that acoustic signal attenuation in water supply pipelines is predominantly composed of distributed losses and local losses. Based on field experimental data collection, an acoustic signal attenuation model was established and validated. Acoustic leak detection in water distribution systems depends on signal propagation along pipes, but attenuation severely limits practical performance. This study experimentally decomposes total attenuation into two mechanisms: distributed loss from energy dissipation along pipes and local loss at fittings. Distributed loss causes exponential amplitude decay, with attenuation coefficients determined by pipe material, burial conditions, and frequency. For buried pipes, mean attenuation is 0.89 dB/m (ductile iron), 2.42 dB/m (cast iron), and 5.50 dB/m (plastic). Local loss from joints, tees, and valves acts as a weak low-pass filter, preferentially attenuating higher frequencies. The magnitude of local loss depends on fitting type, geometry, and connection density. These combined mechanisms explain observed signal variability and constrain detection range. The findings enable improved sensor placement, frequency-selective signal processing, and material-specific localization strategies for heterogeneous water networks, directly enhancing the reliability of real-world leak detection systems.