Clean Air in Cities: Impact of the Layout of Buildings in Urban Areas on Pedestrian Exposure to Ultrafine Particles from Traffic

Research Lead: Suzanne Paulson

UC Campus(es): UCLA

Problem Statement: UCLA researchers recently found that after controlling for traffic, features of the surrounding built environment (i.e., building height and spacing) can result in differences in roadway pollutant concentrations by factors of two to three. The magnitude of the differences differs with the time of day, as the characteristics of atmospheric mixing change). The conclusions are based on field measurements in five urban neighborhoods. More details need to be known about the contributing causes to the increase in pollutant concentrations.

Project Description: This project proposes to develop a numerical model able to reproduce the field data and further explore the causes of the large differences previously observed and to further explore the influence of the built environment on street level pollution concentrations. Modeling complex urban areas at high spatial resolution is computationally prohibitive with most modeling frameworks; therefore, a modified and efficient dispersion model (“Quick Urban & Industrial Complex" or “QUIC”) is proposed. QUIC is an empirically based, fast-response model with computing time of minutes to hours developed to model dispersion of toxics released in urban areas. This modeling environment can be effectively used with a large data set covering multiple sites and including multiple variables. The model also has potential to predict benefits of different urban configurations.

Status: In Progress

Budget: $87,000

Project Partner(s): California Air Resources Board

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