Typhoon Nina–Banqiao dam failure

Typhoon Nina - Banqiao Dam failed, catastrophic dam failure occurred in Henan Province (tropical cyclone) in China in August 1975. The subsequent floods caused more than 150,000 casualties and became one of the most deadly typhoon disasters in history.

In the early 1950s, the Banqiao Dam was built in the Weihe River as part of the flood control and power generation plan to manage the Yellow River. It is 387 feet (118 meters) tall and has a capacity of about 17.4 billion cubic feet (492 million cubic meters) designed to withstand flooding of "1000 years" (ie, once a thousand year flood level) I'm waiting. However, typhoon Nina stopped in Henan Province in early August, causing 2 times the flood of 1000 years level. Total rainfall on the first day exceeded 40 inches (1,000 mm), exceeding 1 / 5th of the annual precipitation in the area, followed by heavy rain for three days.

Dam began to collapse at 1 a.m. on August 8, generating some 33 feet (10 m) and 7 mile (11 km) of water in some areas, moving about 30 miles per hour (50 km) did. . Downstream Dowentown was quickly overwhelmed and all 9,600 citizens were murdered. Due to a typhoon and the flood including the second dam of the flood protection system following it, Honghe's 46,000 dams, a total of 61 other dams and reservoirs also failed. According to the official number of deaths, the early warning system and evacuation plan did not exacerbate the disaster and 26,000 people died of the flood. In addition, an estimated 145,000 people have died of epidemic diseases (due to water pollution) and famine, and it is estimated that the total death toll is over 220,000 people. More than 10 million people affected by the earthquake

After the earthquake, the Chinese authorities conducted a nationwide survey of reservoirs. Chen Jing of the famous hydrologist was not warned or criticized during the construction of Banqiao Dam and was brought back to help clean up the river. Many of the 62 destroyed dams, including Banqiao (completed in 1993) and Shimentan (1996), were rebuilt

In the worst case large dams can cause devastating floods. The Banqiao Dam disaster in 1975 was a failure of the most fatal dam in human history, 171,000 people died, more than 2 million people evacuated. In the past three days, a particularly stable typhoon called Neena caused a breakdown of record breaking in Henan Province of China. The flood that occurred in 2000 caused a Banqiao dam, a reservoir dam of 500 million cubic meters, which caused a downstream chain reaction. The People's Republic Air Force was forced to destroy several other dams by air strikes to further prevent uncontrolled floods

The collapse of the most serious dam in history occurred in 1975 when a typhoon hit the Banqiao Dam in the Weihe River in China. About 4 feet of rain fell in a day. A small dam at the top ruptured and the water wall was washed downstream. A total of 62 dams failed at this event and water of 10 to 20 feet of water fell down to the plain below. In order to curb floods, some dams were intentionally destroyed and wanted to relieve pressure. Approximately 230,000 people were killed

The dam was designed to withstand a flood of 1000 years (300 mm rain per day), but after typhoon Nina collided with the cold front, a flood occurred in August 1975 in 2000. . The typhoon was blocked for two days, after that the direction eventually changed from northeast to west. Due to this very early thunderstorm system, rainfall for more than a year fell within 24 hours (1060 mm) and the average annual precipitation exceeded about 800 mm. The designed capacity of the Banqiao Reservoir is 492 million cubic meters, but it is necessary to respond to the flooding exceeding 697 million cubic meters.

In the early 1950s, the Banqiao Dam was built in the Weihe River as part of the flood control and power generation plan to manage the Yellow River. The height is 387 feet (118 meters) and storage capacity of about 17.4 billion cubic feet (492 million cubic meters) designed to withstand the flood of "1000 years" (that is, once a thousand year flood level) I have. However, typhoon Nina stopped in Henan Province in early August, causing 2 times the flood of 1000 years level. Total rainfall on the first day exceeded 40 inches (1,000 mm), exceeding 1 / 5th of the annual precipitation in the area, followed by heavy rain for three days.