9781422277515

Words to Understand

alluvial fan— a fan-shaped layer of sand and gravel laid down by water. arid— used to describe an area with less than 25 cm of annual rainfall. arroyo— a temporary watercourse in an American desert that fills only after rare rainstorms. dormant— describes animals or plants in which all life processes have almost stopped, usually until warmth or water wakes them up, sometimes after years. oasis— a fertile spot in a desert, supplied with underground water. playa lake— a lake in a hot region that has no drainage stream, which collects water that then evaporates in the hot climate. precipitation— natural water that falls from the sky in the form of rain, snow, sleet, hail, dew, frost and fog. transpiration— the loss of water vapor from plant leaves. wadi— a temporary watercourse in a North African or Arabian desert that fills only after rare rainstorms (the same as an American arroyo).