River Delta
The power of a river cannot be understated. Rivers can, after all, carry people, boats and ducks!
As the river runs into the sea, the water swirls and churns in its channel; it continues to erode the banks and
the channel becomes wider.
This is the mouth of the river, but the gradual widening that leads to the sea is called an estuary.
Estuaries are not only often wide, but are usually deeper than other parts of the channel as well. This
makes them ideal for larger ships and boats to travel along, so you might see large factories and warehouses near
the mouth of a river.
By the time the water reaches the sea, it is carrying a lot of things; this is called the load. The load
could consist of very small items (sand, small stones) called silt, or larger items, such as rocks that roll along
the riverbed, or pieces of wood.
However, when the water meets the sea, its journey is over and the speed of the current slows down.
Of course, with a drop in speed, the water no longer has the power to carry all its load, so this is dropped too -
this is called deposition.
All the things that are carried by the river over time gradually build up and the course of the river spreads out as the
water becomes shallower.
However, there is now the same amount of water travelling through a shallower entrance to the sea, so more transportation
takes place - the river channels its way through the deposited material, but might find several ways to the sea.
The result of this, rather complicated procedure, is that the mouth of the river could be split into a collection of
smaller rivers - this is called a Delta