The Mississippi

Facts

Location

Map reproduced from the Oxford Practical Atlas with permission from Oxford University Press.

The Mississippi river is the fourth longest in the World. Its main tributary is the Missouri, which makes it over 6000 kilometres in length. The source of the Missouri river is high in the Rocky Mountains in a state called Montana. The river is nicknamed "Big Muddy" as it transports a lot of sand and mud and appears as a very muddy river. The Missouri flows south and enters the Mississippi as a tributary a few miles north of St. Louis.

The source of the Mississippi is near Lake Itasca in Minnesota. The Mississippi turns south at the Grand Rapids where it drops 20 metres over the Falls of St. Anthony of the USA. It then continues its journey south through the cities of Memphis and New Orleans towards its mouth at the Gulf of Mexico. There is a delta at the mouth of the Mississippi. The Mississippi is the boundary for 10 states.

The Mississippi and transport

The Mississippi became an important route for transport and trade early in the 19th century. It is navigable from the Falls of St. Anthony in Minneapolis to its mouth. Cargo ships, barges and even paddle steamers transport both cargo (grain, paper, cotton, iron and steel) and people along the Mississippi. Cities and industries have grown up along the banks of the Mississippi because it is a natural waterway fro transporting goods.

Agriculture

It is a source of water for irrigation which is why agriculture is important along the banks of the Mississippi. The Mississippi has a particularly fertile floodplain which has shrunk by 10% over the last 100 years because people are trying to control the river to prevent it from flooding. The floodplain doesn't receive mud and silt deposits any more.

Flooding

During the last 100 years, there has been a major flood once every 7 years along the Mississippi. The floods are most common between January and April when heavy rain falls over the centre of the USA. The whole river system becomes so full with water that the water spills over the banks and onto the surrounding land. Millions of dollars of damage is done to houses, railways, roads and peoples property. The government has built levees (man-made banks), flood walls (concrete walls), floodways (extra parts to river channels) and dams (wall across a river) to try and prevent flooding.

Sandbars

The Mississippi carries a lot of sediment in its water. Sand gets deposited in the delta channels to form sand bars. Sandbars are a problem for ships as if a ship hits one, it can damage the propellers and the ship can get stuck. Dredgers are used to constantly clear the channels. They are huge vacuum cleaners which suck the sediment up and deposit it on the river banks.

Photograph in Comptons Encyclopedia