1. V-shaped valleys.
In the mountains near the source, the river cuts into the land as it flows down steep slopes. This vertical erosion as well as the movement of weathered material creates the V-shaped valley. The river winds around obstacles of hard rock creating interlocking spurs.
A waterfall occurs when a layer of hard rock lies over a layer of softer rock. The hard rock is less easily corroded creating a steep slope and rapids. Eventually a drop develops over which the water falls.
Meanders are curves in a river caused by sideways (lateral) erosion. Meander bends are found in lower areas of the rivers journey to the sea. Erosion on the outside of the meander bend, where the water is flowing fastest, and deposition on the inside means that the river channel 'migrates'. The 'migration' forms a floodplain, over which the river floods in periods of high rainfall.
4. Oxbow lakes.
As a meander continues to erode sideways, the loop of the bend becomes tighter. If it becomes too tight, the river might cut across the neck of the meander to form a straight river channel. The loop is cut off from the main river channel and is now an oxbow lake.
As the river nears its mouth it has a large discharge and the river channel is deep and wide. The valley is also wide with an extensive floodplain. Each time the river floods, silt is deposited on the floodplain. This creates fertile soils. Natural levees are raised banks of deposited material found either side of the river channel. Levees are formed because coarse and heavy sediments are deposited first, near the channel, when the river floods.
Source: GCSE Geography for WJEC A Revision Guide by Dirk Sykes and Stacey Burton-McCabe