Intrazonal soils have more or less well-defined soil profile characteristics that reflect the dominant influence of some resident factor of relief or parent material over the classic zonal effects of climate and vegetation.
These soils are formed in mountainous regions out of fine grains produced by weathering.
However, due to various reasons, this fine grained material constantly slides down the slope.
In river plains, particularly in flood-plain areas, new alluvium is deposited every year.
In river plains, due to alluvium and availability of water, the farmlands are fertile but the soils remain immature.