2022年长江流域夏秋旱情特征及应对策略

Characteristics and countermeasures of summer and autumn drought in the Yangtze River Basin in 2022

2022年夏秋季,长江流域发生了大面积的气象干旱和水文干旱。基于长江流域670个雨量站点降水数据和实测整编水文数据,从降水形势、枯水径流等方面综合分析了2022年长江流域夏秋季旱情的演变态势及总体特征,从天气系统及气象角度分析了旱情成因,总结了长江流域水库群抗旱保供水联合调度过程,提出了应对长江流域干旱的应急调度对策及建议。研究结果表明,2022年6—10月长江流域累计面降水量458.0 mm,仅为多年同期均值的2/3;受有效降水持续偏少影响,长江干流及主要支流来水量持续偏少,尤其以7—10月为甚;旱情主要受大气环流异常影响,副热带高压长时间大范围控制长江流域,夏季梅雨期过短、入陆台风少,导致持续干旱少雨,最高气温连续突破历史极值。为缓解长江流域严重枯水对供水和灌溉的影响,8月中旬和9月中旬实施两次长江流域水库群抗旱保供水保秋粮丰收补水调度,保障了长江流域粮食安全和供水安全。

In the summer and autumn of 2022, a large-scale meteorological and hydrological drought occurred in the Yangtze River Basin. Based on measured precipitation data and compiled hydrological data of 670 rainfall stations, the evolution trend and overall characteristics of drought in summer and autumn in the Yangtze River Basin in 2022 were comprehensively analyzed from the aspects of precipitation situation and dry runoff. And the causes of drought were analyzed from the perspective of weather and meteorology system. The joint regulation operations of reservoir groups in the Yangtze River Basin in response to drought was summarized, and emergency regulation countermeasures and suggestions to cope with drought in the Yangtze River Basin were proposed The results shown that the cumulative surface precipitation in the Yangtze River Basin from June to October 2022 was 458.0mm, which was only 2/3 of the mean precipitation of annual same period. Affected by the continuous lack of effective precipitation, the main stream of the Yangtze River and its main tributaries continued to have less water, especially from July to October. The drought was mainly affected by abnormal atmospheric circulation, subtropical high pressure controlled the Yangtze River Basin for a long time and with a wide range, the summer rainy period was too short, and there were few onlanding typhoon,resulting in continuous drought and little rain, and the maximum temperature continuously exceeded the historical extreme. In order to alleviate the impact of severe dry water on water supply and irrigation, two drought-resistant and water supply operations and autumn grain harvest replenishment dispatches were implemented in the reservoir group in the Yangtze River Basin in mid-August and mid-September, ensuring food security and water supply security.