Super Typhoon Nina (international designation: 7503, JTWC designation: 04W) was a short-lived but intense 1975 super typhoon that caused major damage and deaths in China, mainly from the collapse of the Banqiao Dam. Over 100,000 people died because of the resulting floods, making it one of the deadliest tropical cyclones recorded in history . The collapse of the dam due to heavy floods also caused a string of smaller dams to collapse, adding more damage by the typhoon.
A well defined trough line extending southeastward into the Philippine Sea spawned a disturbance on July 29
. After initial status as a disturbance, Tropical Depression 04W moved southwestward for 36 hours as the structure of the system began to organize. On July 31
, the depression slowed down and began to rapidly intensify
to a tropical storm and was named "Nina" then it began to turn to the northwest. A subtropical ridge prevented Nina from turning further north and it began to track west-northwest just before reaching typhoon intensity.
Nina underwent explosive development on the late hours of August 1. Aircraft reconnaissance reported a 64 hPa drop of pressure on the same day as well as August 2 with wind speeds increasing from a mere 65 kt (75 mph, 120 km/h) to 130 kt (150 mph, 240 km/h) during that period and it attained its peak intensity of 135 kt (155 mph, 250 km/h) later that day. The typhoon began to weaken as it approached Taiwan, making landfall near the coastal city of Hualien as a Category 3 storm with 100 kt (115 mph, 185 km/h) winds.
The storm began to weaken as it battered across the island's central mountain range, sparing the most populated areas from the eyewall. It entered the Formosa Straits as a weak typhoon and the storm came ashore near Jinjiang, Fujian, China. After moving toward the northwest and crossing Jiangxi, it turned north on the night of August 5 near Changde, Hunan. A day later, the storm moved over Xinyang, Henan, and later at Zhumadian, Henan for three days, and the typhoon brought heavy rainfall, causing the infamous collapse of the Banqiao Dam. The storm moved southwest on August 8, and dissipated soon afterwards.
The impact of Nina upon Taiwan
was moderate since it made landfall in the central mountains, far enough away from any population centers to restrict the destructive winds near the center.
Nina was only a tropical storm at landfall on mainland China
, yet caused much more destruction near the Huai He
. Setting the highest rainfall record of 1062mm/24h in Mainland China, the Banqiao Dam
received 2000-year flood conditions and collapsed the same way a string of smaller dams collapsed. In all, 62 dams failed during the disaster, causing large temporary lakes
and $1.2 billion (1975 USD, $4+ billion 2005 USD) in damage.
The death toll for Typhoon Nina will most likely never be known for sure; official body counts are scarce. However, it can be safely assumed that tens of thousands of residents perished in the cataclysm and likely over 100,000 more from an epidemic resulting from the floodwaters. Nonetheless, Nina was the 2nd deadliest typhoon in recorded history in the West Pacific, behind an unnamed typhoon that hit Haiphong, Vietnam in 1881. Nina was also the 6th deadliest tropical cyclone ever recorded worldwide and was also the deadliest named
cyclone ever recorded, but the exact death toll from Cyclone Nargis
is not known, and likely never will be.