Building a dam will decrease the velocity of flow. Immediately behind the dam, where the lake is formed, the slope of the river is essentially reduced to zero. These changes result in the deposition of sediment. Lakes that are formed behind dams must often be dredged because of this velocity decrease and deposition. Downstream from the dam the sediment load is zero, and the slope is increased.
Velocity is higher.
These changes enable the river to use its energy in downcutting and deepening its channel and the valley in which it flows. Note that there are many other examples you might choose to discuss. You could write about what happens when increased runoff in an area results in increased discharge, and how this increased discharge in turn causes changes in w, d, v, s, n, and load.