Frank Herbert’s Dune was originally started as a non-fiction article on sand dunes in Oregon. From an LA Times article:

The novel was sparked when, in the late 1950s, Herbert flew to Florence, Ore., in a small chartered plane to write about a U.S. Department of Agriculture effort to stabilize sand dunes with European beach grasses. The author was struck by the way dunes could move, over time, like living things — swallowing rivers, clogging lakes, burying forests. “These waves can be every bit as devastating as a tidal wave . . . they’ve even caused deaths,” he wrote his agent, beginning an article, “They Stopped the Moving Sands,” that was never published.