What does the term 'river discharge' refer to?

The term 'river discharge' refers specifically to the volume of water flowing through a river at a given point over a specified time. It is typically measured in cubic meters per second (m³/s) and provides insight into the river's flow rate and overall water content. Understanding river discharge is crucial for various applications, including flood management, water resource planning, and assessing the ecological health of riverine environments.

The other options relate to different aspects of rivers but do not define discharge. For example, while the speed of water flow is important for understanding the river's dynamics, it does not capture the overall volume. The area of land surrounding a river pertains to the river's floodplain or watershed, and quality of water addresses pollution levels and biological health, neither of which is directly involved in measuring discharge.