What is defined as a natural watercourse that flows from upland areas to the sea?

A river is defined as a natural watercourse that flows from upland areas to the sea. It typically has a significant volume of water and often serves as a key feature in the landscape, shaping the environment and supporting various ecosystems along its banks. Rivers are crucial for transporting water, nutrients, and sediments from inland areas to oceans or seas, playing a vital role in the hydrological cycle.

While streams and creeks are also types of watercourses, they are generally smaller in size and can be considered tributaries to larger rivers. Wetlands, on the other hand, refer to saturated areas that can support both aquatic and terrestrial plants but do not flow in a directional manner like rivers do. Thus, the distinct characteristic of a river is its larger scale and its journey from higher elevations to a terminal body of water, typically the sea.