Robert Smithson wrote an essay in the early 1970s entitled "Fredrick Law Olmsted's Dialectical Landscape," which considers the design of Central Park, it's naturalistic aesthetic lineage within 18th and 19th C. ideas about the picturesque, and contemporary uses of the park by hoods, homosexuals, graffiti writers and the like. Sounds very promising. Found here:

Smithson, Robert (1996), Flam, Jack D., ed., Robert Smithson: The Collected Writings, Berkeley: University of California Press,