How is the landform called a wadi formed?

Answer 1

The falling of rain in deserts in an occasional feature. however, when it does occur; it comes in short heavy downpours. These produce sudden rushing torrents which sweep down the hill sides and transport large quantities of rock fragments, sand and gravel. This material cuts deep gullies which enlarge with successive heavy rainfall and results in the formation of deep steep-sided valley called WADI. With stoppage of rain, they also become dry.