Revealing Nighttime Construction-related Activities from a Distributed Air Quality Sensor Network

Jintao Gu, Bo Yuan, Jiajun Gu, Shaojun Zhang, Ye Wu, K. MAX ZHANG, Cornell University

     Abstract Number: 548
     Working Group: Urban Aerosols

Abstract
In this study, we analyzed the spatial and temporal patterns of coarse PM (PMc) levels in a 165-node PM monitoring network in Xi’an, China, covering both urban and rural areas in the municipality. We employed a novel technique called network analysis, focusing on peer-to-peer comparison within the network. The network analysis revealed the existence of an unknown, nighttime local driver unique to the urban areas, causing the highest PMc concentrations in the city. Through further analysis using satellite-based aerial imagery and data-mining of internet resources, we confirmed with high confidence the local driver to be related to construction emission sources, both at the construction sites and from diesel traffic transporting construction materials. The peak PMc concentrations from late night to early morning often triggered both noise and air pollution complaints from local residents. Based on our findings, we also recommend policy makers to re-assess the construction-related policies by considering the trade-offs among safety, air quality and noise.