Episodes of rainfall exceeding 200 mm in 24 hours, once rare, are now multiplying along the Yangtze basin and in southeastern China, transforming rice fields into flooded zones in just a few hours. This increase, attributed to climate disruptions, threatens over a third of China's cultivated areas, according to a study led by Dr. Haoyu Hu of Manchester University.
What the study reveals: increase in extreme rainfall and threats to crops
The analysis, published in September 2026, shows that the probability of intense rainfall events has increased significantly over the past two decades. Researchers have identified an increase in episodes exceeding 150 mm in 24 hours, particularly in the provinces of Guangdong, Fujian, and Hunan, where agriculture represents more than 20% of national rice production. This intensification results in sudden floods that overwhelm drainage systems, causing immediate loss of young plants and soil erosion.
Moreover, the study highlights the increasing uncertainty in forecasting scenarios with heavy rainfall. Traditional climate models based on atmospheric dynamic equations struggle to capture the micro-scales of convection that generate these downpours. As a result, farmers often lack reliable warnings, complicating protective measures such as crop elevation or temporary dyke reinforcement.