Due to the combined influence of global warming and the El Nino phenomenon, the precipitation in South China up until now has exceeded twice the usual amount for this period, meteorological experts said at an online news conference on Wednesday.
"Since April of this year, South China has experienced over double the typical precipitation for the same period, marking the second-highest level since 1961," said Zheng Zhihai, chief forecast at the National Climate Center.
Zheng said that provinces like Guangdong, Guangxi Zhuang autonomous region, Zhejiang, Jiangsu and Shanghai have experienced higher than normal temperatures against the backdrop of climate change. This temperature increase has elevated the atmospheric moisture levels, intensified convective processes, and led to more frequent occurrences of heavy rainfall.
"In addition, influenced by the El Nino phenomenon, the subtropical high pressure in the western Pacific has remained strong since April, directing ample water vapor from the South China Sea and the Bay of Bengal toward the southern regions of China. This, combined with circulation anomalies in the Qinghai-Tibet Plateau and South China, has led to numerous occurrences of rainstorms," he said.
Zheng added that South China typically enters the pre flood season in April, characterized by frequent heavy rainfall and severe convective weather. However, in previous years, the range and duration of these events were less severe, as the water vapor had not arrived in the regions yet.
"The world has entered a new phase of climate change, which is characterized by an increased frequency of extreme weather events, resulting in the occurrences of sudden climate and weather-related disasters," said Ding Yihui, academician of Chinese Academy of Engineering, in a previous interview with the China Meteorological Administration.
Affected by heavy rainfall, the Beijiang River in the Pearl River Basin saw the first flood of the year on April 7, the earliest since floods in major Chinese rivers began being numbered in 1998. On Saturday evening, massive flooding hit the Beijiang River for the second time, leaving at least four dead and 10 missing.
It is expected that another wave of heavy rainfall would hit regions such as Guangdong, Guangxi Zhuang autonomous region, Hunan, Zhejiang, Shanghai and eastern Guizhou from Wednesday to Friday, said Sun Jun, chief forecaster at the National Meteorological Center.
"The accumulated precipitation in areas of the central and northern areas of Guangdong, the coastal regions of Guangdong and the northeastern Guangxi Zhuang autonomous region during this period is expected to reach 100 to 240 millimeters, with some areas experiencing 250 to 300 mm," Sun said, adding that the areas affected by the rainstorms exhibits significant overlap with the previous occurrence.
Sun also said that there is expected to be ongoing rainfall toward the end of this month.
Nong Mengsong, chief forecast at the meteorological center in the Guangxi Zhuang autonomous region, warned of the increased risk of geological disasters resulting from the convergence of the impacted areas.
Nong said special attention should be paid to guarding against secondary disasters such as floods, mudslides, landslides and waterlogging, and precautions should be taken to mitigate the safety hazards caused by lightning strikes and intense winds.
In a long-run forecast, Hou Aizhong, chief hydrology forecaster at the Ministry of Water Resources' information center, said this year's flood season, which started on April 1, will feature a concurrence of droughts and floods, with floods being more widespread.
Hou said the seven major rivers in China — the Yangtze, Yellow, Haihe, Liaohe, Huaihe, Songhuajiang and Pearl rivers — are likely to experience different levels of rainstorms and flooding.
The Pearl River basin mainly includes Guangdong, Guangxi Zhuang autonomous region, Yunnan and Guizhou.
