[wvbdmp]

It’s not always destructive as in “to crush”, it can also lend an air of diffusion, dispersion, fraying at the edges, which is perhaps closer to the idea of “sprawl”. I’m not Swiss, so it could be different there, and I can’t speak to how common “Zersiedlung” is in Switzerland. In Germany I would say it’s probably strictly a governmental/admin term of art, if anything.

[ahartmetz]

In my German-speaking opinion, Zersiedlung is more about destruction of landscape than about fraying of settlements. You don't say that a village is zersiedelt, you do say that a landscape is zersiedelt.

[Propelloni]

You are right. "Zersiedlung" is a term of art in land-use and development planning to describe the undirected expansion of settlements into rural areas. I happen to work in the periphery of planning and approval and the term comes up quite often. The English equivalent would be the mentioned "suburban sprawl".