Dynamic assessment of the COVID-19 lockdown in the Xinjiang region using night-time light remote sensing

China used to have the world's most stringent prevention policies during the COVID-19 pandemic. The strict lockdown in Xinjiang region in 2022 was considered to be the longest in the process of COVID-19 pandemic prevention. Therefore, we examined the dynamic effects of the COVID-19 lockdown in Xinjiang region using night-time light data. The findings showed that before the outbreak of COVID-19, the night-time light in Xinjiang region still maintained a significant growth. However, after the lockdown of COVID-19 in August 2022, the night-time light showed a significant decrease, especially in August. Urumqi's night-time light decreased by at least 25% compared to the non-lockdown, while that in other major cities was between 5% and 15%. After the lockdown was lifted in November 2022, the night-time light in Urumqi increased by at least 50% compared to the lockdown, while that in other major cities was generally less than 30%. The regions where night-time light decreased in Urumqi were mainly within a radius of 40 km, whereas that in other cities were mainly concentrated within a radius of 6 km. The changes in statistical data and night-time light indicated that the economic activities in Xinjiang region were significantly affected by the COVID-19 lockdown.