The volume of water flowing through a river at a specific point is discharge.

• A. Baseflow
• B. Phreatic zone
• C. Percolines
• D. Discharge

Answer: (D)

Discharge is the volumetric flow rate of water passing a point in a stream. It captures how much water moves past that location per unit time. At a cross-section, it’s typically defined as Q = A × v, where A is the cross-sectional area of the flow and v is the average velocity, giving units like cubic meters per second. This directly describes the volume of water flowing through the river at that specific point.

Understanding the other terms helps reinforce why discharge fits. Baseflow refers to the portion of streamflow that is sustained by groundwater seeping into the river between rain events, which contributes to the total flow but doesn’t define the rate at a particular cross-section. The phreatic zone is the saturated underground layer where groundwater resides, not the flow rate of surface water. Percolines aren’t a standard way to describe river flow at a point; they relate more to infiltration or groundwater processes than to the instantaneous river discharge.