2. River Basins The area of land drained by a river and its tributaries is called a river or drainage basin. One river basin is separated from another by a natural ridge called a watershed. Rainwater runs down either side of this ridge just like on the ridge of a roof, flowing into one river basin or another. The Amazon’s river in Brasil has a basin the size of Europe! River Basin

3. Mouth The end of a river where it flows into the sea. RIVER BASIN The area of land drained by a river and its tributaries. Tributary A small river that flows into a larger one. Source The beginning of a river. Watershed The boundary separating two river basins, usually a natural ridge. Rill A brook or very small stream.

4. Click here to take you to the River Basin Smart Notebook file.River Basin Smart Notebook