Abstract
Green infrastructure (GI) is adopted as one of the passive control measures in urban areas to reduce air pollutant concentrations and urban heat island (UHI) mitigation. However, current dispersion models offer limited modelling options to evaluate its impact on ambient pollutant concentrations. The main aim of this research is to develop an integrated GI assessment approach to quantify the GI’s individual effects (deposition or aerodynamic dispersion) as well as their combined impact on air pollutant concentration reduction and related health benefits as along with UHI effect mitigation under different GI scenarios. The comprehensive literature review indicated there is a significate research gap in considering GI in readily available dispersion models which can evaluation of its impacts on pollutant concentrations, UHI and health benefits. Three feasibility studies and an air pollution health risk assessment study were conducted using developed integrated approach to demonstrate in the University of Surrey’s hometown, Guildford, that has large urban green spaces as well as strong traffic sources inside. In selected study area, traffic emissions, annual deposited amount and pollutants concentration reductions and related health benefits were estimated along with the possible impact of vegetation types on UHI under numerous GI scenarios for the current (year 2015) and the future (year 2039). The future emission estimations show that Clean Air Strategy adopted by the government will have a significant reduction on exhaust emissions such as NOx, PM and ToNE by promoting electrical vehicles. The results indicate that coniferous trees were found to promote enhanced turbulence flow, offer more surface for deposition, provide higher shaded area to reduce UHI and helped to reduce mortality and morbidity burden compared to deciduous trees, grassland and No-GI. Moreover, planting coniferous trees near traffic lanes was found to be a more effective solution to reduce annual pollutant concentration.