What is the term for the volume of water that flows through a stream over time?

The term for the volume of water that flows through a stream over time is "discharge." Discharge is a critical concept in hydrology and describes the amount of water that passes a given point in a river or stream over a specific period, typically measured in cubic feet per second (cfs) or cubic meters per second (cms). It reflects both the width and depth of the stream, as well as the speed of the water's movement.

Discharge is significant in understanding water availability, ecology, and the dynamics of river systems. It helps assess the capacity of a river to transport sediment, support aquatic ecosystems, and manage water resources for human needs. Understanding discharge is also essential for predicting flooding events and implementing effective water management policies.

Other terms, such as velocity and flow rate, are related but do not fully capture the concept of discharge. Velocity refers specifically to the speed of the water flow, while flow rate is often used interchangeably with discharge but may not encompass the same breadth of information regarding the total volume over time. Current describes the movement of water, but again, it lacks the specific quantitative measure of volume that discharge provides. Therefore, discharge is the most accurate term for the volume of water flowing through a stream over time.