This year's flood season has come to an end, but the exam questions left by the flood have not been replaced with the end of the flood season. The Ministry of Water Resources introduced yesterday (5th) that in the face of the severe situation of frequent river floods and concurrent north and south floods, all localities and departments have gone all out to win the tough battle of flood and drought disaster prevention and effectively safeguard the safety of people's lives and property.
This year's flood situation in our country is extremely severe and complex, and one of the key influencing factors is the rapidly developing El Niño phenomenon. In September this year, a super strong El Niño event formed in the equatorial central and eastern Pacific. By October, it had developed into the strongest El Niño event ever recorded. So, what impact will it have on my country's winter flood season and next year's flood season?
In layman's terms, El Niño is like a seawater "fever" in the equatorial Pacific. It is a natural air-sea climate phenomenon. Its typical feature is that the sea surface temperature in the central and eastern equatorial Pacific continues to be abnormally high. El Niño generally occurs every 2 to 7 years, and a single process usually lasts for 9 to 12 months. Therefore, El Niño is not the weather on a certain day, but a climate background that lasts for several months or even a year. Sun Chunpeng, deputy director of the Information Center of the Ministry of Water Resources, said that in September this year, a super strong El Niño event formed in the equatorial central and eastern Pacific. By October, it had developed into the strongest El Niño event in the history of monitoring records. It is still developing and is expected to reach its peak in late autumn and early winter.
Judging from this winter, the Ningmeng River section of the Yellow River is the "old battlefield" of Lingshui. What we have to face this year is not simply cold, but is likely to be "hot and cold." Sun Chunpeng said that due to the influence of El Niño and global warming, the overall temperature across the country is expected to be higher this winter. The Inner Mongolia section of the upper reaches of the Yellow River will see the first trough in late November and the first closure in early to mid-December, both of which are later than the same period in normal years. The rise in temperature will not "reduce" the burden on the ice. Fluctuations in temperature will make it easier for ice to accumulate in narrow places, forming ice jams and ice dams, which may increase the risk of ice and floods in the Yellow River.
Sun Chunpeng, deputy director of the Information Center of the Ministry of Water Resources: Especially in the Ningmeng River section of the Yellow River Basin, the temperature fluctuates significantly in winter, and river closures are sudden and unstable, and there may be multiple flows and river closures. During the river closure period, the frequency of cold air activities is heavier, the length of the river closure may be longer, and the first closure and first closure may be later.
It is worth noting that in addition to the impact of the El Niño event in the current year, the lagging impact is often greater. It not only sets the tone for this year, but also leaves the "remaining warmth" until next year. For example, the El Niño event in 1997 led to the Yangtze River Basin floods and the Songhua River floods in 1998; the 2015 El Niño event led to the Yangtze River Basin floods in 2016. Sun Chunpeng analyzed that this year's El Niño event is stronger than in 1997 and 2015, and may have a heavier impact on our country. It is expected that the probability of extreme weather and climate events will increase next year.
Sun Chunpeng: In terms of river floods, we have initially determined that there is a risk of basin-wide floods in the Yangtze River Basin, Taihu Basin, and Songhua River Basin, and floods of varying degrees will also occur in other river basins. Local extreme rainstorm and flood events may occur frequently, frequently and repeatedly. Against the background of rising temperatures, the risk of glacial lakes on the Qinghai-Tibet Plateau and surrounding areas has further increased. In terms of drought, regions such as northwest and northern China may have less precipitation and higher temperatures, and drought may occur.
This super El Niño event has made the extreme, destructive and compound chain effects of flood disasters more prominent, which has put forward higher requirements for defense patterns, engineering resilience, and dispatching and command. Yao Wenguang, director of the Flood and Drought Disaster Prevention Department of the Ministry of Water Resources, said that the end of this year's flood control is the beginning of next year's flood control work. He will closely track the development trend of the super El Niño event and conduct rolling analysis and judgment on the impact of my country's precipitation, temperature and Regarding the impact of floods and droughts, we will conduct in-depth investigations and rectification of weak links and hidden risks in river basins and areas where extreme heavy rains, basin floods, flash floods, droughts, and sudden changes in droughts and floods are likely to occur, and implement various prevention and response measures in advance.
