Spatiotemporal analysis using Google Earth Engine: An evaluation of Covid-19 emergency response mobility policies in Java island, Indonesia

The term of Mudik (in Bahasa) is often interpreted as the return of migrants from foreign areas to their hometowns, or largely known as massive mobility among regions that especially carried out annually during the Eid al-Fitr holiday in Indonesia. However, due to the COVID-19 pandemic occurred in 2020 and 2021, restrictions were placed on mudik during the Eid holiday. This study was conducted to see the extent of the effectiveness of the mudik restrictions carried out by the Indonesian government. This study was conducted by reviewing the levels of NO2 and CO in the months before and during the Eid al-Fitr holiday through spatiotemporal processing of images retrieved from Google Earth Engine. The data used is Sentinel-5p images to map air pollution levels from NO2 values and CO values in January-June 2019-2021. The study area includes two districts in DKI Jakarta Province and two districts in Central Java Province. The statistical tests are useful to see the trend of data that is obtained from the zonal analysis process. The statistical tests were carried out using the Mann-Kendall Test method to detect trends and the results were equipped with Sen's Slope analysis to measure the magnitude of the changes that occurred. According to the trend of NO2 and CO values obtained, the values in 2019 are higher than in 2021, and the values in 2021 are higher than in 2020. Thus, the policy of mudik restrictions in 2020 is assumed more effectively than in 2021. The trend in the levels of NO2 and CO in the air is more significant a month before the Eid al-Fitr holiday than in the Eid al-Fitr holiday. It can illustrate that the production of NO2 and CO from motor vehicles continues to increase before there are restrictions. © 2021 SPIE.