The Yellow river is the second longest river in China and the sixth longest river in the world. It starts in the Bayan Har Mountains and flows through nine provinces until it ends in the Bohai Sea. The Yellow river is extremely important in Chinese history as it is considered the birthplace of northern Chinese civilization and was an extremely prosperous region China’s early existence. Devastating floods from this river have since changed this river and its region from prosperous to the name “China’s Sorrow”. Two catastrophic floods have devastated the area around the Yellow River, the first in 1887 and the second in 1931. These floods not only affect the population but also have catastrophic affects on the economy and agriculture of this region.The Yellow river basin and its area is prone to floods due to its geography. The area around the river is very flat and ideal for farming. The river can be broken into three different stages, the upper reaches, middle reaches and lower reaches.
The Upper Reaches starts at the rivers source in Bayan Har Mountains and ends at Hekou County in Mongolia. The land in this section consists or pastures, knolls and swamps. There are over 20 gorges in this section which provide power to many hydroelectric plants. At the end of the upper reaches the river flows through the Yinchuan Plain and Hetao Plain. These areas are mostly desert and grasslands and the speed of the river slows dramatically. The Hetai Plain is traditionally an irrigation plain.The Middle reaches is the section between Hekopu County, Inner Mongolia and Zhengzhou in Henan. It is in this section that many tributaries feed into the river and increases its speed by over 40%. Most of the silt in the river is picked up here as there is a lot of erosion from the Loess Plateau. This sediment makes it the most silt laden river in the world, much different from the clear waters found in the upper reaches. This sediment is later deposited in the lower reaches of the river elevating the river bed.
The middle reaches consists of the longest continuous valleys called Jinshaun Valley and is the second best area for using hydroelectric plants as energy sources. The lower reaches of the Yellow River are from Zhengzhou to the Bohai Sea. This section of the river is lined with levees and the sediment collected from the middle reaches has caused the riverbed to be several meters higher than the surrounding ground. (Sinclair, 1987)The 1887 Yellow River flood is considered to be one of the deadliest natural disasters ever recorded. This flood killed between 900,000 to 2,000,000 people.
The land around the Yellow river is very flat and ideal for farming. Farmers were able to keep the rising water in check using dikes but the rising river in conjunction with a few days of heavy rain caused the river to overflow the dikes and flood the area. The water was able to flood throughout most of northern China due to the low laying plains and covered an estimated 50,000 square miles. An estimated 2 million people were killed in this flood, not only from the actual flood but due to the pandemic that followed as many were homeless and could not receive proper food, care or basic living essentials. (Waterlow, 1993)There was a second devastating flood of the Yellow river in 1931 that lasted from July to November of 1931. There were between 1,000,000 to 4,000,000 estimated deaths for this catastrophic flood as with the flood of 1887 the casualty numbers also include those that died after the flood due to disease and famine. It is this flood that is considered to be the worst flood of all times, over 34,000 square miles were flooded and an additional 8,000 square miles partially flooded.
As with the 1887 floods the 1931 flood is due to monsoon rains which caused flooding in the yellow river but also in the tributaries that feed into the river and the levees that withheld the water broke. (Waterlow, 1993)The Yellow river is prone to tremendous floods because of its high silt content, as in much of the middle and lower reaches about 60% of the weight of the river is due to silt. This yellow mud then settles and chokes the river causing its banks to overflow. Preventing floods of the yellow river began as early as the third century BC when the river was dredged to encourage water flow (Dodgen, 2001). The Chinese have used levees, some as high as 30 feet, channels and dams to attempt too control the river. Dams are considered the most effective but still become clogged by the silt. (Nova, 1997)The river is also more prone to floods as large ice blocks form in the section of the river that flows through Mongolia.
These ice blocks act like natural dams and hold back the water. When the ice blocks melt or are broken the water is then released in a rushing wall of water that creates a flood. The deforestation of the upper reaches mountains has increased the amount of silt in the river, which in turn will increase the flood heights.The death toll from these floods is so high because of the large population that has settled in a close proximity to the Yellow river. The most densely populated regions of northern china are by the Yellow river and the water from the river is used as a source of irrigation for most of the agriculture and industry in Northern China even to this day. There have been more previous flooding of the Yellow river including one that was human induced in 1938, but the 1931 flood was the last of the natural floods that brought about such large amounts of damage. (Brush and Wolman, 200&)The causes of both the 1887 and 1931 floods from the Yellow river are the same, heavy rain.
While there have been many other floods by the yellow river the causes have been varying from the military tearing down the dikes as a military manoeuvre, to ice blocks in the Mongolia regions. These floods did not reach the horrific lengths that the 1887 and 1931 floods due by massive amounts, described as monsoon like, heavy rains. Due to the formation of the river, very narrow and swift flowing at the beginning to broader and slower, the deluge of water caused a massive increase in moving water and silt uptake and completely over flowed its banks. This is particularly easy to do in the lower reaches since the banks of the river are actually at a higher elevation then the surrounding area.The Chinese government is still taking steps to try and regulate the flow of water in the Yellow river and the deposit of silt. A massive dam has been approved for construction that will hopefully be able to prevent any massive floods. Though the only way to completely prevent any further damage from floods is to move the population away from the flood zones. Unfortunately thins would drastically effect the economy and population as the river encompasses a large portion of northern china that specializes in agriculture.
Even further cities along the Yellow river are slowly becoming culture hot spots and tourist destinations. (Brush and Wolman, 2007)While it is unfortunate that so much life has been lost due to the overflowing of the river that is a risk that must be taken into consideration when one chooses to live in this region. Man has not yet been able to tame nature and as the Yellow river has displayed, nature can be a fearsome beast. With the current climate changes underway it is most likely that the flooding will decrease as the river will slowly begin to decrease due to temperature increase and a lack of rain. Though with the current advances in science and technology the Chinese people will at least have some advance warning on floods and be able to vacate the dangerous areas decreasing the loss of life, though still suffering economically.