Uncovering the Air Quality Benefits of Urban Forests Using UAV Surveys

Lihua Huang; Sohail Ahmad; Chunping Miao; Fengxian Chen; Leila Mohaghegh; Ali Cheshmehzangi

doi:10.53941/ubs.2026.100005

Abstract

Urban forests play a critical role in air quality regulation in urban areas. This study aimed to utilize unmanned aerial vehicles to monitor the concentrations of NO₂, O₃ and PM₁₀ at multiple heights during the autumn days in 2022 to evaluate the vertical effects of urban forests on air quality in Shenyang, China. Result showed that NO₂ concentrations at 0–1.5 m were 46.99 ± 12.86 µg/m³ in the streets, which was significantly lower than 51.64 ± 7.33 µg/m³ in forests at midday. However, there was no significant difference in O₃ and PM₁₀ concentrations at 0–1.5 m between in the forests and in the street. NO₂ and O₃ concentrations at 1.5–30 m in the forests were significantly lower at that at 1.5–30 m in the street, while PM₁₀ concentrations at 1.5–30 m in the forests were significantly higher at that at 1.5–30 m in the street. The purifying effects of the urban forests on NO₂, O₃ and PM₁₀ gradually strengthened from midday to afternoon.

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