What are streams in arid regions that flow only after a heavy rain called?

The term for streams in arid regions that flow only after a heavy rain is described as ephemeral streams. These streams are characterized by their temporary flow, which occurs during periods of intense rainfall when the ground is unable to absorb excessive rain quickly. In arid environments, these conditions are more pronounced due to the generally low precipitation levels throughout the year. Once the rain ceases and dry conditions return, these streams will often completely dry up, hence the name "ephemeral," which means lasting for a very short time.

Other terms related to water flow, like seasonal streams or intermittent streams, refer to different patterns of water flow. Seasonal streams typically flow during specific seasons, whereas intermittent streams have longer periods of flow, but still do not remain constant year-round like permanent streams. Ephemeral streams are thus uniquely adapted to the challenging conditions of arid environments, capturing the brief moments of flow that come with rare heavy rainfall.