ASSESSING THE IMPACT OF COVID-19 ON HUMAN ACTIVITIES IN THE GREATER TORONTO AREA BY NIGHTTIME LIGHT IMAGES AND ACTIVE COVID-19 CASES

This paper explores the effect of COVID-19 outbreaks on human activity through nighttime light images of Greater Toronto Area (GTA), Canada. The methods used in this paper include image preprocessing, image classification, and spatial analysis. By using the nighttime light radiance data from VIIRS/NPP data products and COVID-19 cases and comparing this data from the pre-pandemic year, the impact of COVID-19 was analyzed. The result shows that during the pandemic year the monthly average nighttime light radiance has decreased about 4.3-5.0% compared to the pre-pandemic year. The classification results shows that the average percentage of changes in residential areas, public facilities, and commercial areas are 0.3%, -0.7%, and -1.2%, respectively of each corresponding month. Meanwhile, the spatial analysis results show population distribution patterns in GTA during the pandemic year. Overall, the nighttime lights (NTL) images can be used for a preliminary understanding of how COVID-19 affected human activities and is corroborated with other forms data collection used for the pandemic analysis.