The microrelief of soils produced by expansion and contraction with changes in moisture is known as

The microrelief of soils produced by expansion and contraction with changes in moisture is known as Gilgai microrelief. A gilgai is a small, ephemeral lake from a depression in the soil surface in expanding clay soils. Gilgai is found worldwide wherever cracking clay soils and pronounced wet and dry seasons are present. Gilgai is also called melonholes, crabholes, hogwallows or puff and shelf formations.