How does water move through arheic drainage systems?

In arheic drainage systems, water does not follow a consistent or well-defined path to the sea or an inland basin. Instead, water falls unpredictably in small amounts and follows haphazard drainage patterns.1

Because these regions typically lack the consistent moisture required to support continuous vegetation, the landscape is often unprotected, leading to intense fluvial activity during rare, irregular rainstorms. In these environments, most bodies of water are temporary, with the exception of allogenic rivers—which originate outside the region—and areas fed by underground sources. When water does flow, it often moves through ephemeral channels, such as arroyos, where much of the water is quickly absorbed by the dry stream bed or lost to evaporation.231