variability

Streams and river are subject to tremendous variability in flow rate.

Different weights of vehicles and conditions of tires also create variability.

Aquifer Storage and Recovery or ASR is a relatively new technology that can help smooth out variability in water resources where the geology makes it possible.

In fact, different geologic layers affect the presence and movement of groundwater more than any other factor, which is why there is so much variability in groundwater resources across the world.