River Processes and Profiles

River Profiles

Long Profile

• Describes change in gradient from source to mouth
• Steep in upper course, progressively shallower downstream

Cross Profile

• Shape of valley and channel at different courses
  • Upper Course: narrow, deep, V-shaped valley; steep sides
  • Middle Course: wider, more open V; valley sides begin to gentle
  • Lower Course: very wide, almost flat valley; gentle gradient toward mouth

River Erosion Processes

• Hydraulic Action: sheer force of water dislodges material from bed & banks
• Abrasion (Corrasion): river’s load scrapes/grinds bed & banks
• Attrition: load particles collide, becoming smaller & smoother
• Solution (Corrosion): soluble minerals dissolve into water