1. Hydraulic Action
   1. Definition
      1. involves
         1. weight
         2. speed
      2. erodes
         1. cracks
   2. Bank caving
      1. banks
         1. underminded
         2. turbluent water
   3. Cavitation
      1. loose material
         1. broken away
            1. bubbles
            2. collapse
2. Abrasion (Corrasion)
   1. erodes
      1. bed
      2. banks
   2. uses
      1. load
   3. effect
      1. further erode
   4. why
      1. greater volume and speed
      2. greater the erosion
3. Attrition
   1. erodes
      1. load
   2. uses
      1. friction
         1. load itself
         2. bed
   3. effect
      1. creates
         1. sand
         2. silt
         3. pebbles
4. Solution (Corrosion)
   1. erodes
      1. weak rocks
         1. chalk
         2. limestone
   2. uses
      1. chemically