摘要
受全球气候变化和人类活动影响,极端干旱事件越来越频繁,威胁着我国水资源开发利用及管理、生态系统建设及经济社会发展。2022年长江流域发生“汛期反枯”且偏枯严重的异常现象,对流域内生产、生活、生态用水产生了极大影响。分析长江流域2022年降雨情势、实测水位和枯水重现期,介绍了补水调度策略及效益,总结了本次干旱的成因,结果表明:(1)从降雨情势、实测水位及枯水重现期分析结果看,2022年长江流域汛期发生了极端干旱。7—10月,长江流域累计面雨量291.2 mm,仅为多年同期均值的61%,为1961年以来历史同期最少;主要控制站水位在8—10月均达历史同期极枯值,月平均水位和月最低水位均显著低于多年平均值;宜昌站和螺山站2022年7—10月来水量为同期系列中次小,枯水重现期约30~60 a;汉口站、大通站来水量均为71年来同期最小,枯水重现期约70 a。(2)精细化水库群联合调度一定程度上缓解了流域干旱期间水位偏低趋势。2022年8月,纳入联合调度的控制性水库群共补水88.7亿m^(3),较不补水情况下抬高长江中下游干流及两湖控制站水位0.4~1.3 m,有效减缓了长江中下游的退水趋势。(3)拉尼娜事件为2022年6月中旬起长江流域高温干旱的发生发展提供了重要的气候背景条件,大气环流异常、枯水高温持续时间长、沿江取用水需求大加剧了流域缺墒均是造成长江流域2022年汛期极端干旱的重要因素。研究成果可为长江流域干旱分析研究、加强水资源统一调度管理水平、有效提升旱情应对能力等方面提供技术支撑。
Affected by global climate change and human activities,extreme drought events are increasingly threatening China's water resource development,utilization,management,ecosystem construction,and economic and social development.In 2022,the Yangtze River Basin experienced an abnormal phenomenon of"severe drought during the flood season"and severe drought,which significantly impacted the production,living,and ecological water use in the basin.This article analyzes the measured precipitation and water level,and drought return period in the Yangtze River basin in 2022,introducing the joint reservoir operation strategy and benefits,and summarizes the causes of this drought event.The results indicate that:①From the analysis of rainfall,water level,and drought return periods,it can be seen that extreme drought occurred in the flood season of the Yangtze River basin in 2022.From July to October,the cumulative rainfall in the Yangtze River Basin was 291.2 mm,accounting for only 61%of the annual average value,which is the lowest in history since 1961.The water level of the main control station reached the historical extremely low value from August to October,and the monthly average water level and monthly minimum water level are significantly lower than theannual average value.The inflow of Yichang and Luoshan station from July to October 2022 is the second smallest in the same period,with return period about 30-60 year;The inflow of Hankou and Datong stations is the lowest in the same period,with return period of about 70 year.②The joint operation of reservoir groups alleviated the trend of low water levels during dry periods.In August 2022,the controlled reservoir group replenished 8.87 billion cubic meters of water,which raised the water level of the main control stations by 0.4-1.3m,effectively slowing down the trend of water recession in the middle and lower reaches of the Yangtze River.③The La Nina event has provided important climatic background conditions for the occurrence and development of high temperature and drought in the Yangtze River basin since June 2022.Abnormal atmospheric circulation,long duration of low water level and high temperature,and increased demand for water use along the river have contributed to the extreme drought in the Yangtze River basin during the 2022 flood season.The research results can provide technical support for drought analysis and research in the Yangtze River basin,strengthening the unified regulation and management of water resources,and effectively improve drought response capabilities.
作者
张明波
戴明龙
熊丰
李妍清
ZHANG Mingbo;DAI Minglong;XIONG Feng;LI Yanqing(Bureau of Hydrology,Changjiang Water Resources Commission,Hubei 430010;Innovation Team for Flood and Drought Disaster Prevention of Changjiang Water Resources Commission,Hubei 430010)
出处
《中国防汛抗旱》
2023年第7期9-15,共7页
China Flood & Drought Management
基金
国家自然科学基金-长江水科学研究联合基金(U2240201)
水利青年科技英才资助项目。
关键词
长江流域
2022年极端干旱
水雨情
重现期分析
水库补水调度
Yangtze River Basin
extreme drought in 2022
precipitation and inflow conditions
return period analysis
reservoir
