Media reports and Egyptian protest leaders are estimating that 250,000 protesters are gathered in Tahrir Square in Cairo, and the number of protesters will reach 1 million on Feb. 1. However, an analysis of the size of Tahrir Square and of aerial images indicates that the crowd is much smaller.
As another day of protests in Cairo and across Egypt wraps up, opposition leaders are calling for a million protesters to turn out in Cairo and Alexandria on Feb. 1. Reports from Jan. 31 claim that an estimated 250,000 people (far greater than crowd size estimates from Jan. 30, which put the number of protesters between 4,000 and 20,000) have gathered in Cairo's Tahrir Square to protest Egyptian President Hosni Mubarak and his regime. There are also reports of thousands more protesting the government in cities across the rest of Egypt. The opposition is using these reports of huge turnouts to support its claim that a large segment of the Egyptian population is voicing its discontent in the streets. However, estimating crowd sizes is difficult to do. Simply "eyeballing" a group will not yield a reliable result, and attempting to estimate the size of a crowd from within the crowd itself is even more difficult. Additionally, parties involved in the protests have an interest in exaggerating the number of protesters in order to make their movement appear more powerful and representative of the broader public. There is a scientific process to determining crowd size using high quality aerial imagery. The U.S. National Park Service has used aerial imagery to estimate turnouts at events including the "Million Man March" in 1995 and U.S. President Barack Obama's 2009 inauguration. The Park Service's methodology is to count the number of individuals in a specific area (10 square meters, for example) to determine average crowd density and then extrapolate that number over the entire area. Adjustments are needed, of course, as crowd density is not homogeneous. (click here to enlarge image) These tools can be used in assessing the size of the turnouts in Tahrir Square in Cairo and in Alexandria. While STRATFOR does not yet have access to high quality aerial images of the crowd in Tahrir Square, we do have access to elevated images looking at the square that help to determine crowd density. This gives us only a certain perspective and does not put us in a position to certify an exact number of protesters. We can start by comparing the area of the Washington Mall, the capacity of which is well documented after years of observation, with that of Tahrir Square. The area directly in front of the U.S. Capitol has an area of approximately 571,000 square feet and a capacity of 240,000 people. Tahrir Square is slightly smaller, at 490,000 square feet. The size comparison indicates that Tahrir Square could not hold 250,000 people, but more like 200,000 — still an impressive number. However, the National Park Service estimated the Washington Mall's capacity based on an average of one person per 2.5 square feet, comparable to the crowd density of a packed subway car. Images of protesters at Tahrir Square from Jan. 30 and Jan. 31 show a crowd density far lower than that. A majority of the protesters appear to be concentrated in the roundabout and central circle of Tahrir Square, which makes up only about 20 percent of Tahrir Square's total surface area. Focusing on this area gives us a maximum crowd size of 40,000. But again, crowd density is far below one person per 2.5 square feet. Images of the center of Tahrir Square show clusters of people and plenty of open space. A rough estimate would be that only half of the central square is occupied — giving us an estimate of about 20,000 people in the square. Certainly this estimate is not based on the rigorous analysis of high-resolution aerial images, but given the resources at our disposal, it is safe to say that in the past few days of protests, the turnout in Tahrir Square has not even approached 250,000 people. An aerial view of Tahrir Square Of course, this can change. As outlined above, Tahrir Square appears to have the surface area to accommodate 200,000 people, if they are tightly packed. However, it appears next to impossible to be able to gather 1 million people in Tahrir Square. STRATFOR has not received any figures indicating that there are a million protesters active in Cairo, so first there would have to be a massive increase in protesters in the city. Second, there is simply no centralized location where that many protesters could meet. Protesters in Alexandria face a similar quandary. For 1 million people to assemble in either city, protesters would have to line up for miles along narrow streets that are highly vulnerable to blockade by the military. In a city with narrow streets confined by apartment buildings and natural boundaries like the Nile River, (or the Mediterranean Sea, in Alexandria) space becomes an issue when trying to stage a mass protest. However, for the time being, it appears that the protesters cannot even fill up the space they have.