Atlanta BeltLine, Atlanta
Atlanta BeltLine, Atlanta © Matthew Pillsbury for The New York Times

This model of urban design has come to be known as landscape urbanism. One of its primary theoreticians, Charles Waldheim, a professor at Harvard’s Graduate School of Design, traces its roots to Frederick Law Olmsted. In his book “Landscape as Urbanism,” Waldheim notes that Olmsted was one of the earliest figures to call himself a landscape architect (though it was a term that Olmsted considered inadequate), and that he was full of visions for integrating landscape and urban life. But Olmsted’s Central Park, for example, is a classic instance of placing nature in opposition to the city: it’s meant to be a balm, an oasis; in rocky, deliberately overgrown sections like the Ramble it mimics the wilderness a city must exorcise and destroy.

The landscape urbanist, by contrast, sees the decline of the industrial city as prompting a variety of opportunities for naturalism. In cities dominated by service economies, Waldheim argues, landscape urbanism can clean up the industrial economy by reintegrating it with the natural world. In so doing, it creates entirely new urban experiences: The High Line makes it possible to saunter in the air, among apartments and offices, at a much slower pace than at street level. As James Corner, a designer of the High Line, once wrote, “The visitor becomes as much a performer as viewer, more deeply engaged in participating in the theatricality of urban life — the promenade as elevated catwalk, urban stage and social condenser.” The experience is nonetheless limited and directed, a kind of soft coercion. You aren’t encouraged to linger on the High Line: with its crush of tourists, it’s more a Manhattan-themed ride than a park.

The new parks aren’t just oases, then; they emphasize the intertwining of landscape and industry. It’s no coincidence that landscape urbanists are beguiled by Detroit, a crumbling monument to what is sometimes called Fordism — after Henry Ford’s mass-production-mass-consumption model — a paradise of dereliction reclaimed by nature. A “formerly urban” space, in the terminology of Waldheim and his peers, it offers little for traditional architecture but everything for an urbanist trained to see value in rescuing the decaying built environment. Detroit, for a landscape urbanist, is a symbol for processes taking place in cities everywhere: once-bustling ports shrunk by the advent of the shipping container, hulking buildings abandoned as low-wage economies replace high-wage ones. In the Qianhai area of Shenzhen, China, Corner designed a new district that reclaims industrial land, repurposing the tributaries of several channels recently used for drainage as “waterfront.”