Worst Floods Recorded Since 1900

The flood of Yangtze and Huai Rivers in China were responsible for millions of casualties, making it one of the deadliest floods in recent history. Floods are classified as wild weather, and they occur when water overflows from its usual confines to land not usually covered by water. A number of causes have been recognized as leading to floods ranging from heavy rainfall, tsunamis, high tides, cyclones, to earthquakes. Floods adversely impact human activities prompting people to implement mitigation strategies to counter their effect including constructing dams and levees. This list consists of the deadliest floods recorded since the turn of the 20th century, in 1900.

Worst Floods Recorded Since 1900

Yangtze River And Huai River

From July to November 1931, central China experienced devastating floods. In the years preceding the catastrophe, the country had been experiencing terrible drought conditions. However, by mid-1931 changes were felt in the form of heavy snowfall and heavy rainfall. Nine Cyclones were also recorded in these months from the normal two per year. The rivers thus held more water than usual, and the Yangtze River was the first to burst its banks. The Huai River soon also overflowed, and the water reached Nanjing, which was the capital of China at the time. A staggering millions of people drowned while others succumbed to water-borne ailments and starvation. The casualties are estimated to number between 1,000,000 and 4,000,000.

Yellow River

The Yellow River flood of 1938 in Central China was human induced. Its creation was ordered by the Nationalist Government under the leadership of Chiang Kai-Shek as an impediment to the advance of Japanese forces during the Second Sino-Japanese War. The destruction of the dike at Huayuankous on the river’s south bank sent water rushing to thousands of kilometers of farmland. An estimated 500,000 - 800,000 people drowned, starved, or succumbed to diseases. This event has been termed as the “largest act of environmental warfare in history.”

Banqiao Dam (Ru River)

The Banqiao Dam lies on the River Ru in the Henan Province of China. The dam’s construction was targeted to contain the Ru River and a precipitation maximum of 300 mm daily. However, in the wake of Typhoon Nina in 1975 water surpassed that threshold and the dam broke. The disaster had not been forecasted, and evacuation activities were hampered by poor communication in the awful weather conditions. By the end of the flood, an estimated 231,000 people had died.

Yangtze River

The Yangtze River causes nearly three-quarters of China’s floods, and in 1935, 145,000 people were killed after it broke its banks. The river is Asia’s longest, and flooding on its banks has been a concern since ancient times. The flooding was fueled by heavy rainfall which began in July. Millions of people were displaced while others suffered from starvation, dehydration, and diseases.

Floods And Climate Change

Scientists have sought to understand why floods are increasing and becoming more deadly and costly. Climate change has been recognized as a contributing factor. As global warming increases, ice and snow are melting leading to the increase of water volume in oceans. Some parts of the world are experiencing heavier rainfall than usual as warm air can retain more moisture. More rain translates to increased flood risks. Human activities including deforestation are also making humankind more vulnerable to floods and other extreme weather conditions.