Human Activity Changes During COVID-19 Lockdown in China-A View From Nighttime Light

Area of Science:

• Environmental Science
• Epidemiology
• Data Science

Background:

• Strict lockdowns were imposed in China to combat Coronavirus Disease 2019 (COVID-19).
• Understanding the impact of these measures on human activity is crucial for public health policy.
• Nighttime light (NTL) data offers a proxy for human activity levels.

Purpose of the Study:

• To explore the relationship between nighttime light (NTL) data and the development of Coronavirus Disease 2019 (COVID-19) in four Chinese cities.
• To analyze changes in human activity across different epidemic stages using NTL radiance.

Main Methods:

• Utilized nighttime light (NTL) data from five distinct Coronavirus Disease 2019 (COVID-19) stages: case-free, newly appeared, rising, outbreak, and stationary.
• Incorporated six categories of points of interest data: company, recreation, healthcare, residence, shopping, and traffic facilities.
• Employed random forest models to associate NTL radiance with epidemic progression and human activity.

Main Results:

• Dimming NTL radiance across four cities correlated with epidemic development and altered human activity.
• Healthcare-associated NTL radiance initially increased in Wuhan and Guangzhou during case appearance but decreased later.
• Company and shopping NTL radiance showed signs of resuscitation in later stages, with variations across cities.
• NTL radiance trends aligned with electric power consumption, more so than with gross domestic product.

Conclusions:

• NTL data effectively reflects human activity changes during infectious disease outbreaks like Coronavirus Disease 2019 (COVID-19).
• Findings provide valuable insights for developing effective control policies for COVID-19 and future infectious diseases.
• The study highlights the utility of remote sensing data in understanding societal impacts of pandemics.