3. Straight channels
• Mainly in the upper zone
• Channel located upon rock
• Single channel with pools and
riffles
• Thalweg moves from side to
side
• Vertical erosion (incision)
predominant
• Saltation and traction main
method of transport
• Main landforms: V-shaped valley,
waterfalls, gorges
4. Braided Channel
• Mainly in the middle zone
• Flows upon coarse alluvial material
• Several roughly parallel channels intersecting at points
• Whole channel system is straight but channels
wander from side to side within the flood plain
• Major deposition occurs after discharge decreases
• Lateral erosion occurs between floods
• Main landforms are multiple channels separate
5. Meandering
• Found mainly in the lower zone
• Channel flows upon fine alluvial material
• Channel wander in a regular pattern from side within
the flood
• Lateral erosion and deposition moves channels across
the flood plain as meanders
• River meanders themselves move downstream
• Suspensions are main method of transport
• Main landforms: levees, ox-bow lakes, point bars, slip-off
slope, bluffs
7. Long Profile of a river
• Graph drawn along the course of a river from the source to
the mouth
• Shows that they have a concave shape with a steeper
upper reach and a gentler lower reach
• Ideal profile is called the ‘graded long profile’
• In this ideal situation, the river is in a state of dynamic
equilibrium where there is a balance between the rate of
erosion and the rate of deposition
• This balance is always transitory as the slope (profile) has to
adjust constantly to changes in the river
• These can cause short-term increases in either the rate of
erosion or deposition until the state of equlibrium has again
been reached
