Geography: Research: A flooding event.

Geography: Research: A flooding event.

What is a flooding Event?

A flood occurs when a large amount of water covers an area of land that is usually dry, this can be due to multiple Man and Natural factors

The Great Yellow River flood:

The Great Yellow flood is to this day one of the deadliest natural disasters ever recorded to this day.

It happened in 1931 in China when the Yellow river flooded killing almost 3.9 million people.

Yangtze River is the largest in China and the third longest in the world. It flows on a 6400km course and flows east to West across the entire country.

[pic 1]                                               Map showing the Yangtze River and its tributaries.

Background to the flooding:

From 1928 to 1930 a long drought proceeded the flood.

In the late winter of 1930 abnormal weather started over central China.

Heavy snow storms in the winter followed by spring thaw/defrost heavy rain that raised the river’s level even higher.

The rain increased into July and August 1931, in July alone, 7 cyclones hit the region this is more than double of the annual number which is two.

Global warming also plays a big role since the temperatures rise, making the Snow melt at the source, this increases the Discharge of the river causing most of the levees to break and, the human activity on the flood plain had been in a constant growth.

Consequences:

As mentioned before, The Great Yellow flood is to this day one of the deadliest natural disasters ever recorded to this day.

It killed around 3.9 million people the flood covered an area of 77,700 square km including the cities of Nanjing and Wuhan and killed and left 40,000,000 more homeless.

[pic 2]Picture showing the people of Nanjing saving their personal goods and walking on the street with water covering them up to their chest.

Response:

China’s response to these floods was a project called “The Three Gorges Dam”.

This project consist on building a dam across the River on a large lake where it’s estimated that 1.3 million people lived. This dam, will prevent from future flooding by: Preventing Seasonal variation in discharge due to the monsoons that happen at summer time, the dam can then regulate the discharge by opening or closing the valves.

Not only will this prevent the flood, but the dam being equipped with 26 turbine, producing around 18.2 Million Kilowatts each, the can serve the need of electric power to almost one seventh of china’s population.

Sources:

1)http://www.history.com/this-day-in-history/yangtze-river-peaks-in-china

2) http://ghs320-cmg-2012f.blogspot.be/2012/09/the-great-flood-of-1931-china.html

3) Mr.Kilgannon’s Geography lessons.

4) http://rside.org/youngauthors/the-great-chinese-floods-of-1931/.

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