Which term describes a temporary drainage feature that appears during specific weather events and disappears later?

Which term describes a temporary drainage feature that appears during specific weather events and disappears later?

• A. Perennial channel
• B. Intermittent stream
• C. Ephemeral erosion
• D. Dune field

Answer: (C)

The key idea is how drainage features are described by how long they carry water. A feature that only shows up during specific rain events and then disappears is ephemeral—water appears briefly after precipitation and the channel dries out again. Ephemeral erosion captures what happens during those short-lived flows: rapid, temporary channels form or widen as runoff carves the landscape, but once the event passes, the water is gone and the feature isn’t a persistent stream. In contrast, a perennial channel carries water year-round, an intermittent stream flows for longer periods between events, and a dune field isn’t a drainage feature at all. So describing a temporary drainage that appears with weather events and then vanishes aligns with ephemeral erosion, since it emphasizes the transient nature of both the flow and the erosion it causes.

The key idea is how drainage features are described by how long they carry water. A feature that only shows up during specific rain events and then disappears is ephemeral—water appears briefly after precipitation and the channel dries out again. Ephemeral erosion captures what happens during those short-lived flows: rapid, temporary channels form or widen as runoff carves the landscape, but once the event passes, the water is gone and the feature isn’t a persistent stream. In contrast, a perennial channel carries water year-round, an intermittent stream flows for longer periods between events, and a dune field isn’t a drainage feature at all. So describing a temporary drainage that appears with weather events and then vanishes aligns with ephemeral erosion, since it emphasizes the transient nature of both the flow and the erosion it causes.