JULY 2020
This report is available in Chinese here.
Long-duration and high-intensity rainfall since June has caused multiple landslides and widespread flooding across many parts of central and eastern China, with 24 out of 32 provinces impacted thus far. The floods are the worst to affect the country since 1998, when countrywide floods affected one fifth of China's population, caused over 3,000 fatalities, and left 15 million people homeless (ReliefWeb).
Record River Levels
Although East Asia experiences an annual rainy season, the magnitude of rainfall is particularly severe. The extreme rainfall has been associated with the West Pacific Subtropical High (a semi-permanent, sub-tropical anticyclone of high pressure) which has been particularly strong this year, bringing more moisture from the northern Indian Ocean (CGTN.com). The intersection of warm and cold air has led to continuous heavy precipitation and widespread flooding (CGTN.com).
The most significant flooding has occurred within the Yangtze Basin which extends across southern and central China. This includes the provinces of Chongquing, Hubei, Anhui and Jiangxi, with the cities of Wuhan, Jiujiang (with Poyang Lake) and Tongling severely affected.
Due to the high volume of water entering rivers and lakes, water levels rose quickly, causing many to burst their banks. Since June, 433 rivers have surpassed warning levels and 33 rivers have reached record highs (CGTN.com). According to China’s Ministry of Water Resources, the Poyang Lake, China’s largest freshwater body, rose 2.5m higher than its warning level.
Social and Economic Impacts of Flooding
Over 38 million people are believed to have been affected by the ongoing rainfall and flooding. A total of 141 people are recorded as dead or missing, over 28,000 homes damaged, and 2.24 million residents displaced, according to the Ministry of Emergency Management (as of 13 July). It is reported that 8.72 million acres of farmland and unharvested crops have been destroyed (CNN).
On 8 July, heavy rainfall in Huangmei County provoked flash floods and a landslide that resulted in 9 missing persons and 40 people displaced (FloodList). One of the hardest-hit areas, Anhui province, has ordered all residents in its five cities neighbouring the Yangtze River to evacuate. In this province alone, ongoing flooding has forced over 300,000 people to relocate and affected more than 2 million people. Here, high water levels stemming from the Yangtze River and lakes prevent flood waters from receding (Chinadaily). In response to high water levels in Anhui province, on 19 July, officials in central China used explosives to destroy a dam along the Chu river with the aim of dropping water levels by 700mm (The Guardian).
Nationwide, the floods are estimated to have caused 82.23 billion yuan ($11.75 billion) of economic losses (CNN). More than 100,000 people have engaged in relief efforts across inundated towns of southern and central China, with emergency workers attempting to buttress embankments with sandbags and dig channels to divert flooding (RTE). The Chinese military reports that over 7,000 army soldiers have been mobilised to shore up embankments and dikes, evacuate residents and lead rescue operations (XinhuaNet).
Outlook
Flood waters have been slow to recede and downstream areas of the Yangtze river have continued to receive high amounts of rainfall over recent days. Heavy rain is forecast to continue into other areas of China. Some of the same locations already hit by flooding are forecast to receive more rain this week, including Jiangxi and Hubei where between 500 and 1,500mm is predicted (CNN). Heavy rain is also predicted to move into other regions including southern Guizhou, northern Guangxi and south-eastern Tibet (China Meteorological Administration).
JBA’s Event Response team will continue to monitor the event.
JBA Risk Management has nationwide return period flood maps for China at 30m resolution and a Global Flood Model to help you understand and manage flood risk more effectively. Please get in touch for more information.
