Deltas are wetlands that form as rivers empty their water and sediment into another body of water, such as an ocean, lake, or another river. Although very uncommon, deltas can also empty into land.
A river moves more slowly as it nears its mouth, or end. This causes sediment, solid material carried downstream by currents, to fall to the river bottom.
The slowing velocity of the river and the build-up of sediment allows the river to break from its single channel as it nears its mouth. Under the right conditions, a river forms a deltaic lobe. A mature deltaic lobe includes a distributary network—a series of smaller, shallower channels, called distributaries, that branch off from the mainstream of the river.
There are four main types of deltas classified by the processes that control the build-up of silt: wave-dominated, tide-dominated, Gilbert deltas, and estuarine deltas (Delta, n.d.).
Deltas: where rivers meet their destiny, building new land one grain at a time. What fascinating deltas have you explored or learned about? Share in the comments!
