Chapter 7, Lesson 2 Landforms runoff tributary watershed sediment meander flood plain delta water gap canyon valley dune landslide

runoff – water that runs off Earth’s solid surface

tributary – “feeder” streams; small streams and rivers that “feed” into other streams and rivers forming larger streams and rivers

watershed – the entire area from which water is drained

sediment – pieces of material; sediment can range in size from boulders to gravel, sand, silt and dissolved materials

meander – bends, or “S” shapes in a river cause by river currents slowing down in flat land and dropping sediment Click here to learn more about rivers and coasts!

flood plain – flat landscape near rivers; the rivers flood the land from time to time and create very fertile soil.

mouth (of river) – where a river empties into the ocean; river currents slow when they hit the ocean and drop sediment

delta – a fan-shaped piece of land that forms from sediment dropped at the mouth of a river

water gap – a rare, narrow, steep-walled canyon created as water cut through hard rock

valley – formed when small channels are deepened and widened by erosion

canyon – a deep, V-shaped valley that is usually created as a result of both water cutting into earth and geological forces pushing earth upward

dune – sand hill created by wind erosion; found in deserts or at the beach

landslide – when water saturates the land and makes soil loosen and fall; gravity can create landslides, too