what is a dry river gulch called

A dry river gulch is called an arroyo. The term "arroyo" comes from the Spanish word for "brook" and refers to a dry creek, stream bed, or gulch that may temporarily or seasonally fill with water. It is a type of landform that is similar to a gulch, which is a deep V-shaped valley formed by erosion that may contain a small stream or dry creek bed. In some regions, the terms "arroyo," "gulch," and "wash" may be used interchangeably to refer to dry riverbeds.