The Yellow River or Huang He is the third-longest river in Asia, following the Yangtze River and Yenisei River, and the sixth-longest in the world at the estimated length of 5,464 km. Originating in the Bayan Har Mountains in Qinghai province of western China, it flows through nine provinces, and it empties into the Bohai Sea near the city of Dongying in Shandong province. The Yellow River basin has an east–west extent of about 1,900 kilometers and a north–south extent of about 1,100 km. Its total basin area is about 742,443 square kilometers.
The Yellow River is called “the cradle of Chinese civilization”, because its basin was the birthplace of ancient Chinese civilization, and it was the most prosperous region in early Chinese history. However, because of frequent devastating floods and course changes produced by the continual elevation of the river bed (due in part to manmade erosion upstream), sometimes above the level of its surrounding farm fields, it also has the names China’s Sorrow and Scourge of the Sons of Han.
The Yellow River is one of several rivers that are essential for China’s very existence. At the same time, however, it has been responsible for several deadly floods, including the only natural disasters in recorded history to have killed more than a million people. The deadliest was a 1332–33 flood that killed 7 million people. Close behind is the 1887 flood, which killed anywhere from 900,000 to 2 million people, and a 1931 flood (part of a massive number of floods that year) that killed 1–4 million people.
The cause of the floods is the large amount of fine-grained loess carried by the river from the Loess Plateau, which is continuously deposited along the bottom of its channel. The sedimentation causes natural dams to slowly accumulate. These subaqueous dams were unpredictable and generally undetectable. Eventually, the enormous amount of water has to find a new way to the sea, forcing it to take the path of least resistance. When this happens, it bursts out across the flat North China Plain, sometimes taking a new channel and inundating any farmland, cities or towns in its path. The traditional Chinese response of building higher and higher levees along the banks sometimes also contributed to the severity of the floods: When flood water did break through the levees, it could no longer drain back into the river bed as it would after a normal flood as the river bed was sometimes now higher than the surrounding countryside. These changes could cause the river’s mouth to shift as much as 480 km, sometimes reaching the ocean to the north of Shandong Peninsula and sometimes to the south.
