1. interlocking spurs
2. pot holes
3. waterfalls
   1. why
      1. small in volume
      2. fast flowing
      3. vertical erosion
   2. how
      1. hydraulic action
      2. abrasion
   3. Topic
4. V shaped vally
   1. downwards cutting erosion
5. Characteristics
   1. steep gradient
   2. Fast flow
   3. Small volume
   4. Vertical erosion