 Water is responsible for a majority of all erosion on Earth  Runoff - after rain the water remaining on the surface is called runoff. › As runoff moves downhill, it forms small grooves called ___________________. › As the rills flow into each other they form ________________________. › Water continues to flow downhill and becomes streams and rivers.

 1. Amount of ________________.  2. Amount of ___________________.  3. Type of ______________________.  4. Shape of _____________________.  5. How land ____________________.

 MORE RUNOFF = MORE EROSION!

 River systems start off with streams feeding into rivers, then rivers feeding into larger rivers.  Any stream or river that feeds into a larger river is called a ____________________.  The land area from which a large river and all of its tributaries collect is called a ______________________.

 Through erosion rivers create valleys, waterfalls, flood plains, meanders and oxbow lakes.  Rivers often begin in hilly or mountainous areas and flow fast and straight.  Rivers slow down as land flattens out and create ____________________.  A flood plain is a wide flat area along a river where excess water flows during a flood.

 When a river slows down it often creates a ______________, a loop like bend.  If a meander gets cut off from the river, it forms an _____________________.  When a river slows down it deposits sediment.  If a river flows out of a mountain valley and deposits the sediment it is called a _______________.  A _______________ is created when a river flows into a still body of water, (a lake sea or ocean)

A. erosion B. weathering C. deposition D. mass movement E. I don’t know

A. delta B. meander C. alluvial fan D. oxbow lake E. I don’t know

A. V-shaped valley B. large deltas C. many oxbow lakes D. large alluvial fans E. I don’t know

 Students will draw a picture of a river system; they must include the following: › deltas, › alluvial fans, › meanders, › and oxbow lakes.  Trade and identify a partner’s picture.