Influence of COVID-19 on night-time lights in Czechia
INTRO
Night-Time Light (NTL) satellite imagery is widely recognized and valued as a powerful tool for spatial analysis and research. Despite its global popularity, there is absence of similar studies dealing with NTL intensity in Czechia. Using VIIRS/DNB data, our study focused on analyzing the changes in night-time light intensity before and during the coronavirus restrictions. These restrictions had a substantial impact on social and economic life, particularly during the peak of pandemic, affecting not only Czechia but also other regions worldwide. A mosaic of the study area was prepared, followed by the aggregation of the original raster data to municipalities with extended power (MEPs) and calculation of the average light index (ALI). The resulting typology made it possible to identify regional differences in NTL intensity. The main hypothesis was confirmed, it was observed that the ALIexhibited a decrease of 18% in 2020, whereas in 2021, the decline averaged at 9%.
This research was published in Journal of Maps, for more details see the original article:
Pavlačka, Daniel, Pavel Vyvlečka, Radek Barvíř, Oldřich Rypl, and Jaroslav Burian. 2023. “ Influence of COVID-19 on Night-Time Lights in Czechia .” Journal of Maps 19 (1): 8. https://doi.org/10.1080/17445647.2023.2235381.
DATA PROCESSING WORKFLOW
NIGHT-TIME LIGHT
2021
An important finding that supports our main hypothesis is that the highest average values refer to 2019, before the pandemic started. Then in 2020, they decreased, and finally, in 2021, they increased again but below the 2019 peak.
Night-time light
2020
An important finding that supports our main hypothesis is that the highest average values refer to 2019, before the pandemic started. Then in 2020, they decreased, and finally, in 2021, they increased again but below the 2019 peak.
Night-time light
2019
An important finding that supports our main hypothesis is that the highest average values refer to 2019, before the pandemic started. Then in 2020, they decreased, and finally, in 2021, they increased again but below the 2019 peak.
DIFFERENCE
2021-2019
The same line also has the findings from calculated values of the Index of Change. The mean value of the index for the year 2020 is 91.44, which is almost a 10% decrease from 2019. For the year 2021 the decrease is not that great, but it is still evident. The standard deviation is slightly higher for 2020 compared to 21, and the median is much closer to the mean than in the original values.
DIFFERENCE
2020-2019
The same line also has the findings from calculated values of the Index of Change. The mean value of the index for the year 2020 is 91.44, which is almost a 10% decrease from 2019. For the year 2021 the decrease is not that great, but it is still evident. The standard deviation is slightly higher for 2020 compared to 21, and the median is much closer to the mean than in the original values.
DIFFERENCE IN REGIONS
2020-2019
In 2020 compared to 2019, 181 of 206 MEPs (almost 88%) saw a decrease in NTL intensity. The areas with the highest decline (80% relative to 2019) mainly included the regional cities of Brno, Jihlava, České Budějovice and its surroundings, Ústí nad Labem and the north-western areas adjacent to Praha. A significant decline (90% relative to 2019) is evident in the cluster that includes Prague and its surroundings, extending south, southwest, and northeast to the border, and southeast to Brno. Other clusters occur east of Brno, through Zlín to the eastern border with Slovakia, and in the north of Czechia around Ústí nad Labem. In contrast, the largest cluster with an increase occurs in the west of the country around Karlovy Vary. There is no discernible spatial pattern in the location of other areas with increases.
DIFFERENCE IN REGIONS
2021-2019
In 2021, compared to 2019, 168 of 206 MEPs (almost 82%) saw a decrease in NTL. The number of areas with the most substantial decline (80% relative to 2019) was far smaller than in 2020; the largest are Jihlava and neighbouring Moravský Krumlov. In the southwest, there is a large cluster of areas with a decrease (90% relative to 2019), which does not cover any regional cities, but neighbours České Budě- jovice and Plzeň. This category also includes Praha, Brno and Olomouc. The spatial pattern of the areas of increase is clearly visible. The first such cluster is located in the northwest of the country, including Karlovy Vary. The second lies to the southeast of Prague, and the most important city there is Mladá Boleslav. The third smallest cluster covers Zlín and its surroundings.
DIFFERENCE IN REGIONS
2021-2020
TYPOLOGY
The most numerous type (– + –) includes the most populated cities; Praha, Brno, Ostrava, Plzeň, Liberec, and other regional cities; České Budějovice, Hradec Králové and Jihlava. These are regions where there was an initial decline in NTL in 2020 followed by an increase in 2021, but that did not exceed the 2019 baseline intensity.
The second largest cluster (– – –) are areas where there was a decline in 2020 followed by a further decline in 2021. The only regional town that belongs to this type is Olomouc, from which a cluster of areas of the same type extends to the southwest.
The third most numerous type (– + +) are areas where there was first a decline followed by an increase above the 2019 baseline. The largest cluster of such MEPs is located around the industrial town of Mladá Boleslav. A smaller cluster is located near Zlín, and Pardubice also belongs to this type.
