Final answer:
The power of a river to cause erosion is primarily influenced by the rate of flow, soil composition, topography, discharge volume, and sediment load. Fast-flowing rivers on steep terrains with soft soils cause more significant erosion. External factors such as dams also affect erosional power.
Step-by-step explanation:
The factors affecting the power of a river to cause erosion include the river's flow velocity, the composition of the river bed, the gradient or slope of the terrain through which it flows, its discharge volume, and the amount of sediment it carries. Fast-flowing water is more capable of picking up and transporting sediment, aiding in eroding the river banks and the bed. Soft soil or loose bedrock can be easily eroded compared to hard rock. Additionally, steep slopes and increased runoff usually cause higher erosion rates.
Topography plays a significant role in erosion, as steep soils are more prone to be stripped away than those in flat areas. Concerning river depth, deeper rivers can have lower erosion rates at the bed but may erode the banks more effectively depending on the soil type and vegetation present. Environmental factors such as water temperature, chemistry, and flow characteristics, influenced by external elements like dams and reservoirs, also impact riverine erosion processes.