Spatial analysis of COVID-19 spread in Europe using "center of gravity" concept

The COVID-19 global pandemic has affected all countries and become a real challenge for humanity. Scientists are intensively studying the specifics of the disease caused by this virus and the impact of restrictive measures on the economy, environment and other aspects of life. We present an approach to spatial modeling and analysis of the COVID-19 spreading process using the concept of the "center of gravity". Based on weekly data on this disease in all European countries, the trajectories of the center of gravity of new cases and deaths during the pandemic have been calculated. These two trajectories reflect the dominant role of certain countries or regions of Europe during different stages of the pandemic. It is shown that the amplitude of the trajectory of the center of gravity in the longitudinal direction was quite high (about 1,500 km) in comparison with the amplitude of the trajectory in the latitudinal direction (500 km). Using an approximation of the weekly data, the delays between the peaks of new cases and mortality for different countries were calculated, as well as the delays in comparison with the countries that first reached the peaks of morbidity and mortality. The trajectories of the center of gravity are also calculated for the regions of Ukraine as an example of analysis at the national scale. These results provide an opportunity to understand the spatial specifics of the spread of COVID-19 on the European continent and the roles of separate countries in these complex processes.