because it just is
silt
My alluvial island is formed primarily from silt. The barrier of silt is being washed away from the delta!
Deltas are landforms formed at the mouth of a river where the river meets a body of water, such as a sea or ocean. Silt is a type of sediment that is commonly found in river deltas, as it is carried by the river and deposited in the delta. The accumulation of silt over time contributes to the growth and formation of delta landforms.
Silt is carried downriver on the fast currents until it reaches the slow to nonmoving waters, where the silt forms a delta, which collects more silt.
A delta forms the the mouth of a river that is carrying a silt burden. Probably named after the Greek capital letter Delta.
A delta.
delta
The land formed by deposited soil at the mouth of a river is called a delta (named for the Greek letter, which is similarly triangular in shape).The most well known are the Ganges River Delta, India, the Nile River Delta, Egypt, and the largest is the Amazon River Delta, Brazil.
a river delta for HI2 "delta"
The importance of cataracts was a water source achievement silt fertile soil
lake
Silt and rich soil for farming