Ice jams will choke China’s Yellow River due to global warming, cause devastation, says study

Ice jams will increase in frequency by several notches in the estuary of the Yellow River in China by the end of this century and will severely affect Chinese coastal cities like the ones in eastern Shandong province, says a new study.

The upstream ice starts to break and flows downstream as temperatures start increasing in late winter and early spring. This ice travels downstream to cooler regions where it refreezes and collects, creating ice jams.

These ice jams become a hazard and can be highly destructive, as flooding can occur behind the blockage, and a sudden ice jam collapse can let loose a gush of ice and water, damaging communities, wildlife, and infrastructure downstream.

“By integrating historical records with climate projections, we provide compelling evidence that climate warming is not only driving a long-term decline in ice jam flood frequency but also shifting the geographic distribution of hotspots downstream,” the scientists wrote.

Researchers from Jiangsu Normal University, the Chinese Academy of Sciences, and the University of Bern in Switzerland published their findings in the peer-reviewed journal Science Advances last week after analysing the ice jam floods in the lower Yellow River over the past 160 years.

The Yellow River is the second-longest river in China and the sixth-longest in the world. The river is considered to be the cradle of Chinese civilisation, but is also called “China’s Sorrow” due to the devastating floods in the last two centuries.

The researchers found that climate warming has been shifting ice jam patterns downstream along the lower Yellow River since the end of the Little Ice Age, one of the coldest periods of the past 10,000 years.

They also found that the ice jam hotspots shift downstream by about 86 km (53 miles) with every 1 degree Celsius rise in temperature.

The study’s lead author, Yu Shiyong, professor at Jiangsu Normal University’s School of Geography, Geomatics and Planning, said this would mean coastal cities like Binzhou and Dongying may face increasing exposure to ice jam flood risks and would need proactive adaptation measures.

“Sediment loads will likely decline further, lowering groundwater tables and reducing floodplain fertility, while the Yellow River Delta may erode without sufficient sediment supply,” Yu said.

Global warming may substantially alter precipitation patterns in the North China Plain and lead to more uneven rainfall distribution, with extreme rainstorms becoming both more frequent and intense, Yu added.

“[It demands] a fundamental overhaul of the flood management strategies from engineering-dominance to adaptive dam operations and nature-based buffers. Policymakers must prepare for both water scarcity and catastrophic floods in the same basin and also balance ecological needs with flood protection,” he added.

The Xiaolangdi Dam in Henan province traps a lot of sediment and lacks flexibility for extreme rains.

The dam should not be used just as a flood controller. Its role should shift from passive flood control to active sediment-water regulation with strategic sediment flushing and coordinated releases with upstream dams, he said.

As traditional embankments cannot cope with climate-amplified storms alone, floodplain reconnection and AI-powered early warning systems were needed to handle intense precipitation to navigate between the threats of water scarcity and catastrophic flooding, he added.