th New Hampshire river
By Irrigation and
the soil is rich for farming, and transportation is easy using the river.
Indus River and floodplains of rich soil
Flooding of river floodplains deposits nutrients that enrich the soil. That is why so many farming areas are on floodplains, and why people put up with being flooded again and again.
The soil brought down by the river is called "alluvium." It consists of sediments such as sand, silt, and clay that are deposited along the river's banks and floodplains.
Delta
Two areas where rivers leave rich fertile soil are river deltas and floodplains. River deltas are formed at the mouth of a river where sediment is deposited, creating a fertile area for agriculture. Floodplains are areas along the banks of a river that are periodically flooded, depositing nutrient-rich sediment that enhances soil fertility.
They can fertile soil from mountain slopes onto their floodplains to the south
Alluvial soil is carried and deposited from rivers, streams, and floodplains. It is formed by the erosion and weathering of rocks and minerals upstream, which are then transported and deposited by flowing water.
It can flood and deposit silt (fine soil).
Both the Nile and the Mississippi are long rivers which drain vast areas of the continent. Both have large 'river delta" systems which wash tons of soil from the banks of the river and deposit it in or near the mouth of the river. Before flood control systems tamed each river, the seasonal floods would inundate extensive areas around the river.
Sediments, such as sand, silt, and clay, are fine bits of rock and soil that are deposited on land by a river. These sediments are carried by the river's current and then settle on the river banks and floodplains when the water slows down. Over time, these sediments contribute to the formation of fertile soil and landforms in river valleys.