CHILDREN OF DUNE by Frank Herbert

The sand-blasted world of Arrakis has become green, watered and fertile. Old Paul Atreides, who led the desert Fremen to political and religious domination of the galaxy, is gone.
But for the children of Dune, the very blossoming of their land contains the seeds of its own destruction. The altered climate is destroying the giant sandworms, and this in turn is disastrous for the planet’s economy.