Seven weeks after the State of Emergency was decreed in Spain to curb the Covid-19 pandemic, the country is now embarking on its ‘Transition Plan to the new normality’, which proposes the relaxation of the lockdown rules in four phases, the timing of which will vary by region.
Under this plan, four areas in Spain, specifically the Canary Islands of La Gomera, El Hierro and La Graciosa and the Balearic Island of Formentera started their lockdown exit sooner, because the incidence rate in those regions has been lower. But what is the reason for the lower number of infections? Is there a direct relationship between population density and the number of coronavirus infections? “There is a premise, that perhaps we have all assumed to be true during this crisis: the more people around us, the more exposed we are to contagion. In some cases, this has resulted in an exodus of people from the main Spanish cities to their second homes,” explains Beltrán Pomar, Data Scientist at Brainsre.
However, last Monday, the World Bank issued a report denying a direct relationship between population density and the number of infections. The report analyses data from 284 Chinese cities based on the number of infections, urban density and the distance from Wuhan, where the pandemic originated. “The result: there is no real correlation between density and the number of positive cases. Furthermore, the highest numbers of infections were found in cities with lower densities”, Pomar points out. This influences an important aspect for the control of the pandemic: “greater density can also translate into a greater number of services for residents, which allows for a decrease in the degree of interpersonal contact”.
In the case of Spain, analysis of the correlation between a high population density and a higher rate of coronavirus infection does not yield this conclusion either, according to a study carried out by Brainsre.
“We have conducted a similar analysis focusing on Spain, using the population density in the real urban areas of cities. The conclusions obtained are in line with the aforementioned report; there is no correlation between the two variables”, says the Data Scientist, who, nevertheless, highlights several key factors of this study. “Carlos III University has identified several entry points of the virus into Spain, according to a report published last week, which prevents any analysis with a mono-focal origin, unlike the study in China. In addition, and more importantly, the government is not providing enough open data about the pandemic,” he says.
According to data collected by Brainsre analysts, the average population density in Spain, that is, the number of inhabitants per hectare of urban land, stands at 71.21 nationwide. Provinces such as Vizcaya, Madrid, Navarra and even Asturias exceed 100 inhabitants per hectare.
Nevertheless, according to data provided by the autonomous regions (excluding Cataluña and Galicia, which do not report Covid-19 data by province) until last Monday 27 April, in regions such as Soria, Segovia, La Rioja and Albacete, the number of people infected by coronavirus for every 100,000 inhabitants exceeded one thousand, which was higher than the rates recorded in other areas where the population density is higher such as, for example, Madrid and Valencia.
“It is worth noting that Soria and Segovia have some of the lowest population densities in the country, but some of the highest rates of infection. At the opposite end of the spectrum, provinces such as Vizcaya and Asturias have higher population densities, but lower rates of infection. We are not observing any evidence of a trend”, explains the Brains Data Scientist.
Specifically, Soria leads the provincial ranking with 1,848 positive cases per 100,000 inhabitants, whereas its population density barely reaches 33 inhabitants per hectare on urban land. It is closely followed by Segovia, which has 1,786 confirmed coronavirus cases per 100,000 residents, and a population density of 24 inhabitants per hectare.
In Ciudad Real, where there are 52 inhabitants per hectare of urban land, the number of coronavirus cases stands at 1,486 per 100,000 inhabitants; and in Albacete, there are 1,058 positive cases and a population density in line with the national average: 70.
It’s the same story in La Rioja, where there are 1,229 positive cases per 100,000 inhabitants and a population density below the Spanish average: 66; and Ávila – the region in Castilla y Leon has an infection rate of 950 confirmed Covid-19 patients per 100,000 residents and a population density of 29 inhabitants per hectare.
By contrast, in Guipúzcoa, an area with one of the highest population densities, there are just 359 positive coronavirus cases for every 100,000 inhabitants. The same is true of Valencia, where 233 patients are infected by Covid-19 for every 100,000 inhabitants and the population density amounts to 87 people per hectare.
In Madrid, where the pandemic has hit hard and the population density is quite high (114 per hectare), there are 892 positive cases per 100,000 inhabitants.
“In the specific study of the Community of Madrid (CAM), no relationship was found to exist between the two variables, revealing a significant dispersion,” explains the Data Scientist from Brainsre.
“Excluding the municipality of Madrid, which eclipses the other municipalities in the region due to the high volume of infected cases -around 32,000-, the graph reveals a great dispersion. As such, we cannot be sure that the two variables are correlated”, he adds.
In this way, for example, municipalities such as Villa del Prado, Cercedilla and Guadarrama, which have a very low population density, with between 23 and 47 citizens per hectare, suffer from some of the highest rates of infection in CAM, with more than 1,000 people infected for every 100,000 inhabitants.