PORTO ALEGRE, Brazil — Where there was once a soccer field in this city in southern Brazil, there is a highway. And where there were once shanty homes, there are piles of timber, bricks, and the debris of those who used to live there.
The reason is the World Cup. The mega-event that will play out this summer in a dozen Brazilian cities is driving a frenzy of road construction, airport renovations, and other projects.
The impact is being felt most strongly among the poorest citizens, including residents of Porto Alegre’s largest slum, who have come to regard the soccer championship as synonymous with evictions, removals, and demolition.
Activists say that as many as 250,000 people across the country are threatened with eviction — although some of those efforts have been underway for years and are likely to outlast the soccer tournament as building projects continue. Brazil is also preparing to host the Summer Olympics in 2016.
Some Brazilian officials insist that most displacements are not linked to World Cup preparations. Independent researchers say they have to rely on witness reports. But residents of the Santa Teresa neighborhood here, as well those in other poor areas, say there is no doubt that evictions are underway, as they lose neighbors and open space.
“It breaks a cycle of friendship, a cycle of custom,” said 42-year-old Antonio Daniel Knevitz de Oliveira, who lives deep in the heart of Santa Teresa, where he grew up.
“Brazil is by far and away the champion of forced removals,” said Christopher Gaffney, a visiting geography professor at the Fluminense Federal University in Rio de Janeiro. “This is clearly the most impactful World Cup ever, with a lot of ambitious projects.”
In some of the affected cities, the World Cup and the Olympics are the latest justifications used by authorities to clear slums.
Local government officials often describe the slums — home to more than 11 million Brazilians, many of whom lack property deeds — as ‘‘irregular’’ settlements. Authorities have long attempted to reclaim the land, through evictions or by bringing areas under government jurisdiction.
The added pressure of hosting the two biggest sporting events in the world has given authorities additional incentive to act.
The scale of displacements in Rio de Janeiro prompted Amnesty International to launch a campaign, Enough Forced Evictions, after it found evidence of housing rights violations in the city. A network of Brazilian activists, the National Coalition of People’s World Cup Committees, sought to sound the alarm last year in a report to a UN human rights panel.
That group said as many as 32,000 people in Porto Alegre could be at risk of eviction because of World Cup projects, with more than 1,500 families affected by the road-widening project. Porto Alegre is Brazil’s 10th-largest city, with a rapid rate of economic growth.
About 13 percent of residents live in slums, including those in Santa Teresa who were evicted so that a nearby road could be widened to improve traffic flow around the soccer stadium.