A series of recent flood events which caused widespread devastation across multiple provinces in China could result in economic losses approaching $14 billion in Henan province alone, according to flood specialists JBA Risk Management (JBA).

In a report, JBA said the floods started in late June in the provinces of Sichuan, Jiangxi and Heilongjiang, following successive occurrences of heavy rainfall.

This was followed by unprecedented rainfall in July as flooding occurred in Henan province.

The largest rainfall event observed in Zhengzhou city, located in Henan province, has been classified as a 1-in-1,000-year flood, making it one of the worst events to affect China this year.

The severe floods in July were attributed to the prolonged rainfall deposited in a short period of time across widespread areas.

Next, Typhoon In-Fa made landfall on the Zhoushan Archipelago in Zhejiang Province, on the central coast of eastern China, on 25 July at 12:30pm (local time) with the centre of the storm being 40km south of Shanghai. Maximum sustained winds of 74 km/h (tropical storm) were recorded.

As of 2 August 2021, 302 deaths were officially reported. Economic losses for Henan alone are likely to reach at least $13.79 billion.

JBA’s report added that, according to rainfall gauges, several locations in Henan province experienced 120-400% more rainfall in just 24 hours than the historical average for the whole month of July.

Indeed, over four consecutive days from 17 July, 4,098 weather stations in Henan received 50mm or more of rainfall, with 47% of the stations (1,923 stations) receiving at least 100mm and 15% (606 stations) receiving more than 250mm of rainfall.

JBA noted that 250mm of rainfall is equivalent to the average total July rainfall for the worst affected cities in Henan. For comparison, the average total rainfall in the month of July ranged from 150 – 350mm on average for Zhengzhou, XinYang and SongShan.

The city of Zhengzhou was particularly hit, recording a maximum of 617mm of rain in a 24-hour period – equivalent to its average rainfall for an entire year.

The maximum 1-hour rainfall recorded at Zhengzhou meteorological station was 201.9mm (20 July 09:00-10:00 UTC) which has exceeded the highest 1-hour rainfall record in mainland China, recorded at 198.5mm on 5 August 1975.

To read the full JBA report click here.

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