Breakdown: Why rivers and streams flood

Breakdown: Why rivers and streams flood

MEMPHIS, TN (WMC) - Each year, the Mighty Mississippi river will rise and lower along its journey south to the Gulf of Mexico, but have you ever wondered why a river will overflow its banks?

In this episode of the breakdown we will explain what a flood is and what causes rivers to flood year after year.

First off, what is a flood? Well a flood will occur along a river or stream when it over flows its banks. Seasonal flooding will occur due to spring rains or snowmelt, which can increase the rivers flow.

When a flood occurs, the channel of the river or stream is filled; that means water will move into the floodplain and the water will slow down.

As the water slows, that means it can carry less material. Lots of sand, silt leaves and other materials that were once carried while the water was swiftly moving down the channel are then dropped into the floodplain, thus causing a slower run downstream.

While seasonal floods may be predictable in the sense that they are generally expected to occur at a certain time of the year, they never occur on a strict schedule. The duration of the seasonal flood will depend on the weather taking place.

The larger the river, the more time it takes for the river to flood and the longer the duration of the flood. The reasoning behind this is the water from other lakes and streams are flowing into the larger river, and that takes time for it to happen.

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