Here's a breakdown of the concept:
* Upstream: The direction opposite downstream, towards the source of the river or watercourse.
* Mouth: The point where a river or watercourse empties into another body of water, like a lake, ocean, or another river.
Example: If a river flows from the mountains to the sea, the direction towards the sea is downstream, and the direction towards the mountains is upstream.
Important notes:
* Downstream can also be used to describe the movement of materials, pollutants, or sediment carried by the water, as they travel from their source towards the mouth of the river.
* The term can also be applied to other flowing systems, like air currents or underground water flows.
Understanding the concept of "downstream" is crucial in many aspects of geography, such as:
* Hydrology: Analyzing water flow and its impact on landforms and ecosystems.
* Environmental studies: Tracking pollution and sediment transport.
* Urban planning: Understanding flood risks and managing water resources.