BEIJING — China has announced a sweeping plan to manage the flow of rural residents into cities, promising to promote urbanization but also to solve some of the drastic side effects of this great uprooting.

The plan — the country’s first attempt at broadly coordinating one of the greatest migrations in history — foresees 100 million more people moving to China’s cities by 2020, while providing better access to schools and hospitals for 100 million former farmers already living in cities but currently denied many basic services. Underpinning these projections would be government spending to build roads, railways, hospitals, schools and housing.

Formally announced on Sunday, the plan has been one of the most contentious projects in recent years. Originally scheduled to be announced last year, it backs away from more radical proposals, which predicted even more farmers leaving the land for cities. But the plan is still ambitious, with 30 chapters, covering topics that include Internet access, building standards, environmental protection and safety.

“These are big numbers, but they’re not the crazy numbers that came out last year,” said Tom Miller, a Beijing-based analyst and author of “China’s Urban Billion,” a look at what China’s cities may look like in 2030. “They’re being more realistic than they might have.”