What is the definition of surface water?

Surface water is defined as water that flows on the surface of the Earth, which includes rivers, lakes, streams, and reservoirs. This form of water is readily accessible and interacts directly with the atmosphere and land, making it a critical component of the hydrological cycle. Unlike underground reservoirs, which are classified as groundwater, or water stored in clouds, surface water is visible and can be directly observed in natural water bodies. Understanding this definition is crucial for managing water resources, assessing ecosystems, and studying environmental impacts.