Jericho was a Canaanite city before the Israelites crossed the Jordan (what it was initially no one knows--there would not have been anyone recognizable as a Canaanite at that time), but the Philistines (who gave their name to Syria Palaestina) did not control that part of the land between the Mediterranean Sea and the Jordan River.
I thought "dunam" was a unit of area (analogous to an acre), not a unit of length.