Developing a framework to evaluate the possible application of Natural Based Solutions to improve air quality

PICONE, NATASHA; EMMANUEL, ROHINTON

Sydney

Conferencia; ICUC 11 -; 2023

UNSW

Air quality is one of the main concerns in the urban environment as more than 80 % of the urban population are exposed to air quality that exceed the World Health Organization guidelines. Improving the air quality can be achieved in different ways, the most direct being reduction in pollution emission, which sometimes is difficult as the sources are diffused, or the implementation of the decisions are highly complex. There are complementary methods to reduce the exposure, and currently urban planners are increasingly exploring them. Between these methods are the usage of Natural Based Solution (NBS) to capture air pollutants from the urban atmosphere, particularly by increasing the deposition surfaces with green infrastructure. This work presents a framework to evaluate the possible application of NBS, focusing on vegetation effects, to improve air quality. This is a first step particularly for site selection for further analysis. The tool is a GIS based analysis which focus on two aspects: sources of air pollutants and the public space configuration that could impact the air quality. For each air pollutant the sources (diffuse or fixed) can be analyzed, with a focus on traffic volume, vehicle mix, residential and industrial emissions. Second, the framework focusses urban structure, urban cover, and length scales; also, on street configuration and its relationship with the meteorological conditions, such as wind exposure or orientation. The framework was applied to four cities in Europe: Huelva, Spain; Dresden, Germany; Lahti, Finland and Glasgow, Scotland. Findings indicate that the main opportunity for NBS effectiveness are those with low rate of dispersion and medium traffic. To corroborate this, one of the sites selected in Glasgow, Scotland was modelled in ENVI-MET with different scenarios: base case; linear vegetation and green walls. Implications of findings for Glasgow are discussed in detail.