During a rainstorm, the water that flows over the land as runoff collects in channels such as streams, canals, rivers, etc. The land area that drains water is called a watershed.
During a rainstorm, the water that flows over the land as runoff collects in channels such as streams, canals, rivers, etc. The land area that drains water is called a watershed.
Areas of higher elevation called divides separate watersheds from each other. Water flows through a series of channels and eventually it collects in a wide river that empties into a body of water such as an ocean or lake.
From an aerial view, drainage patterns in a watershed resemble a network similar to the branching pattern of a tree. Tributaries, similar to twigs and small branches, flow into streams, the main branches of the tree. Streams eventually empty into a large river, comparable to the trunk. Like other branching patterns (e.g. road maps, veins in a leaf, the human nervous system), the drainage pattern consists of smaller channels merging into larger ones.