Drainage Basis is an area where all the rivers flow to the lowest point of elevation. Think of the Mississippi River and its tributaries, (Missouri River, Red River, etc) and how it flows down to New Orleans, the lowest point of elevation. Drainage Divide is simply a boundary that separate two drainage basins. read more
A drainage basin is an extent or area of land where water from rain and melting snow or ice drains downhill into a body of water, such as a river, lake, reservoir, estuary, wetland, sea or ocean.A drainage divide is the line separating neighbouring drainage basins (catchments). read more