What is meant by "upstream" in river flow terminology?

In river flow terminology, "upstream" refers to the direction toward the source of a river. This means that if you are moving upstream, you are going against the current and heading towards where the river originates. This concept is essential for understanding the flow of water in rivers, navigation, and ecological studies related to river systems. When discussing river dynamics, identifying upstream and downstream accurately informs various activities such as fishing, kayaking, and conservation efforts, as it helps in understanding water movement and habitat arrangements.

The other options may confuse the directional context regarding river flow. The distinction between upstream and downstream is foundational for anyone working with or studying rivers, making it vital to grasp the meaning of these terms correctly.