rivers

• tributary: a small river is stream that joins a larger one
• confluence: where two rivers meet
• estuary: the part of a river mouth that is tidal
• drainage basin: the area of land that is drained by a river and its tributaries
• levee (deposition): raised banks of alluvium that build up along sides of an old river
• levee steps: occurs when river floods, and begins to spread out over floodplain, it quickly loses its energy and deposits its load. most load (especially the heavier particles) is deposited closer to the banks of the river. after many periods of flooding, these deposits build up to form levees. example: liffey
• abrasion: stones carried by water wear away river banks
• attrition: stones worn down as they hit each other travelling down a river
• hydraulic action: the force of moving water
• solution: rocks are dissolved by acid in water