Monitoring Resumption of Work and Production in Wuhan Built-up Area During COVID-19 Based on NPP-VIIRS and Landsat 8 Data

At the beginning of 2020, an outbreak of the Corona Virus Disease 2019 (COVID-19) broke out in Wuhan, Hubei Province, China. With the effective control of the epidemic, all enterprises gradually resumed work and production. The advantage of remote sensing is that it can obtain a large range of data in a short time, which is conducive to the dynamic monitoring of land surface changes. Therefore, using remote sensing technology to monitor the resumption of work and production in Wuhan built-up area is of great significance to economic and social development. This study presented a Vegetation and Building Adjusted NTL Urban Index (VBANUI) based on NPP-VIIRS and Landsat 8 data to extract the built-up of Wuhan. The extraction accuracy of VBANUI was 5.1%, which was better than the traditional method (based on Nighttime Light (NTL): 9.4% and based on Vegetation Adjusted NTL Urban Index (VANUI): 6.5%). The average value of nighttime light intensity and the proportion of high nighttime light intensity in Wuhan built-up areas from April to June were larger than those from January to March in 2020, increasing by 2.8 nW/cm2/sr and 2.6%, respectively. In general, the nighttime light intensity in the built-up area of Wuhan increased gradually with the resumption of work and production.