1. suspension
   1. small particles are carried
   2. river's turbulence
2. solution
   1. soluble rock
      1. desolve
   2. carry material
3. saltation
   1. bounced along bed
      1. hydraulic action
      2. fall back to bed
4. traction
   1. dragged or rolled
   2. along river bed
   3. terms
      1. bed load drag
      2. traction