Here's why:
* Base Level: This is the lowest point to which a river or stream can erode. It's the level at which the stream enters a larger body of water, such as a lake, ocean, or another river.
* Erosion: Streams erode the land as they flow, carving out channels and transporting sediment. This erosion is limited by the base level because a stream cannot erode below the level of its destination.
* Examples:
* A river flowing into the ocean will have its base level at sea level.
* A river flowing into a lake will have its base level at the lake's surface.
Let me know if you have any other questions!
