Frequent occurrence of climate extremes in the Three Gorges region in 2021

As a key project for the governance and protection of the Yangtze River, the Three Gorges Hydropower Complex Project is the world’s largest water conservancy and hydropower project, providing numerous benefits. In recent years, due to global warming, extreme climate events such as extreme precipitation, high temperatures and regional drought have occurred frequently, and these events themselves, as well as associated geological disasters, represent a challenge to the safe operation of the Three Gorges Project. Therefore, it’s important to keep monitoring climate anomalies and extreme events with high impacts.

In a paper recently published in Atmospheric and Oceanic Science Letters, Professor Xianyan Chen and her team from the National Climate Center, China Meteorological Administration, analyzed the interannual variations in major meteorological variables during the year 2021, with a focus on the climate anomalies and high-impact extremes that occurred in the Three Gorges region (TGR). In this report, the causes of the abnormal high-temperature weather in early autumn, which were not included in previous annual reports (Zou et al. 2020; Chen et al. 2021; Cui et al. 2022), were briefly explained.

“Climate extremes are one of the most important natural factors affecting the safe operation of the Three Gorges Project. We have achieved the goal of 175-m full storage in each of the previous 12 years. On the one hand, it shows that the utilization efficiency of water resources in China has been improved. On the other hand, we are able to provide more refined services for decision-making due to the great contributions made by scientists toward understanding the mechanisms of climate extremes,” says Prof. Chen.

The report points out that the TGR was warmer than usual in 2021, with most regions having received abundant rainfall and frequent extreme weather events. Both the number of rainstorm days and accumulated rainfall broke the observed record in some regions; and the occurrence of cold-air activity in autumn and winter was more frequent. The TGR experienced exceptional high-temperature weather in early autumn, which was driven by abnormal activity of mid- and high-latitude atmospheric circulation over the Eurasian continent and the western Pacific subtropical high.

“We will keep improving our observations of the climate,” adds Prof. Chen. “If we have a much longer series of observational data, we can assess the effect on the climate in the Three Gorges Reservoir area in more detail.”