The factors which affect the work of a river are-
1. Velocity of water — Erosion and transportation are both maximum when the velocity of water is high. Deposition takes place when the velocity of water is low.
2. Volume of water — The larger the volume of water, the greater is the power of erosion and transportation. Deposition takes place better when there is reduced volume of water and when the load is greater.
3. Load — The load of the river does all the work of erosion and deposition. Mass wasting, deepening of river valleys and formation of landforms depend on the load a river carries.