Yellow River

Yellow River
Researchers have investigated a catastrophic Yellow River flood that decimated the Chinese city of Kaifeng—a former imperial capital—in A.D. 1642, providing new insights into a disaster thought to have killed an estimated 300,000 people.

In a study published in the journal Scientific Reports, the scientists examined geological and archaeological evidence, which revealed the flood "destroyed Kaifeng's inner city, entombing the city and its inhabitants within meters of silt and clay"—backing up evidence found in historical documents.

According to the team—led by Michael Storozum from Fudan University, China—the flood was so catastrophic because the walls of the city had partially collapsed during a siege, meaning that most of the floodwaters became trapped inside.

The Yellow River—the second-longest in the country—is sometimes referred to as "China's sorrow" due to its tendency over the centuries to produce devastating floods. In fact, historical documents suggest that the Yellow River has flooded more than a thousand times in the past 2,000 years, resulting in the deaths of millions of people. Some of these events are among the deadliest flood disasters in history.

Kaifeng is located on the river's southern bank in what is now central Henan province. It was previously one of the largest cities in the world, and functioned as the imperial capital of several Chinese dynasties. It is also known for being the victim of several Yellow River floods. In the past 3,000 years, the river has flooded the city around 40 times. However, the event of 1642 was perhaps the most devastating of them all.

Unlike the other floods, this event was not caused by nature but rather by humans. For six months, the city had been withstanding a rebel siege. But when it became clear that the city could not hold out any longer, the governor of Kaifeng decided to take drastic action, which unintentionally ended up costing the lives of thousands of his own people.

"The governor of Kaifeng ordered the waters of the Yellow River unleashed in hopes of destroying the rebel army," Xin Xu and Rivka Gonen—authors of the book The Jews of Kaifeng, China: History, Culture, and Religion—wrote. "The dikes were broken, but instead of hurting the rebels, the raging waters swept over the low-lying city, drowning a citizenry that was totally unprepared. From a population of 378,000, only a few score thousand survived."

According to the study, recent archaeological work conducted at Kaifeng by Storozum and colleagues has demonstrated that Kaifeng's city walls collapsed during the siege, leaving the city unprotected against floodwaters.

"As a result, the constant influx of floodwater into the city created a deadly mix of mud and urban debris that significantly amplified the destructive power of the Yellow River," Storozum and colleagues wrote.

According to the researchers, investigations into past disasters such as these can help shed light on similar events today, especially in a world where climate change is expected to cause an increase in extreme weather around the globe.

"Our investigations at Kaifeng suggest that urban resilience is not static but instead varies depending on the magnitude and type of natural hazard, the built landscape, as well as the city's social institutions," the authors wrote.