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)

Urban noise pollution disproportionately affects Latin American cities, where rapid urbanization, weak governance and limited monitoring networks coexist with diverse economic activities. This study compares the spatial and temporal dynamics of environmental noise between two Colombian municipalities with contrasting urban typologies: Soledad (Atlántico), a metropolitan city dominated by traffic and aircraft noise, and Montelíbano (Córdoba, ~86,647 inhabitants), a mid-sized municipality whose acoustic environment is conditioned by ferronickel mining (Cerro Matoso), heavy-duty transport and small-scale aviation. A two-tier methodology was applied: (i) field monitoring under Colombian Resolution 627 of 2006 (LAeq) at 80 points in Soledad and 30 points in Montelíbano, covering daytime and night-time periods including replicates; and (ii) noise dispersion modelling in SoundPLAN Essential v5.1/6.0 using the ISO 9613-2 propagation method, calibrated with field measurements through an iterative residual-minimization process. Results show that Soledad exhibits a strong day–night gradient (mean LAeq diurnal = 67.7 dB(A); nocturnal = 61.7 dB(A); 96.2% non-compliance at night) with linear-corridor acoustic patterns driven by arterial roads and the Ernesto Cortissoz airport, while Montelíbano displays a near-flat day–night profile (diurnal = 67.1 dB(A); nocturnal = 67.0 dB(A)) consistent with continuous mining-industrial operations. The modelled maps reproduce the measured patterns with mean residuals of −2.72 dB(A) (day) and −2.92 dB(A) (night) in Montelíbano (75% within ±5 dB(A), consistent with international SoundPLAN benchmarks), and mean residuals of +5.78 dB(A) (day) and +1.43 dB(A) (night) in Soledad, the latter reflecting the greater acoustic heterogeneity of a larger urban environment. These findings demonstrate that urban typology shapes acoustic patterns in fundamentally different ways, with implications for sustainable land-use planning, public health and the design of differentiated noise-mitigation policies.