Spatial and Temporal Patterns of Environmental Noise in Two Colombian Urban Typologies: A Comparative SoundPLAN-Based Study Between a Metropolitan City (Soledad) and a Mining-Industrial City (Montelíbano)

This study compares the spatial and temporal dynamics of environmental noise in two Colombian municipalities with contrasting urban typologies: Soledad (Atlántico, >600,000 inhabitants; traffic and airport dominated) and Montelíbano (Córdoba, ~86,647 inhabitants; ferronickel mining and heavy transport dominated). A two-tier methodology integrated field monitoring under Resolution 627 of 2006 at 80 points (Soledad) and 30 points (Montelíbano), with calibrated SoundPLAN 6.0 dispersion models implementing ISO 9613-2 propagation. The central finding is that urban typology produces fundamentally different acoustic fingerprints: Soledad exhibits a strong day–night gradient (working-day mean LAeq diurnal = 73.2 dB(A), nocturnal = 68.1 dB(A); mean ΔLAeq = −5.1 dB(A)), while Montelíbano displays a near-flat profile (diurnal = 67.1 dB(A), nocturnal = 67.0 dB(A); ΔLAeq = −0.1 dB(A)), reflecting continuous mining-industrial operations. Non-compliance rates reach 83.8% (Soledad day), 96.2% (Soledad night), 60.0% (Montelíbano day) and 100% (Montelíbano night). Model validation meets international ISO 9613-2 benchmarks for Montelíbano (75% of residuals within ±5 dB(A); mean residuals −2.72/−2.92 dB(A) diurnal/nocturnal); Soledad shows higher scatter (mean residuals +5.78/+1.43 dB(A)), consistent with the greater acoustic heterogeneity of a large metropolitan environment. These results demonstrate that typology-differentiated noise management policies are needed for effective implementation of Colombia’s Anti-Noise Law (Law 2450 of 2025).