洪湖市2022年高温干旱特征及其影响

Characteristics and Effects of High Temperature and Drought in 2022 in Honghu City

摘要: 2022年夏秋季发生在洪湖市的异常高温干旱事件强度大、持续时间长，对当地的社会经济和自然生态系统造成了严重影响。为深入剖析此次干旱过程及其致灾特点，利用洪湖市长序列气象观测资料，基于干旱事件客观化识别与评估方法，建立历史干旱过程事件库，结合典型年干旱过程灾情资料，对2022年夏秋季干旱的极端性及其影响进行评估。结果表明：2022年洪湖市干旱过程持续139 d，过程内降水距平百分率达−75.4%，相对湿润度指数达−0.79，过程综合强度指数达22.4，为特强等级，在1961年以来113次干旱过程中综合强度位居第一；2022年洪湖市干旱与异常高温和长江流域性干旱叠加，造成地表土壤相对湿度大部时段低于65%，洪湖水体面积缩减近10%，长江螺山站水位较历史最低水位偏低1.5~3.3m，洪湖水位创2010年以来同期新低，连续多日低于最低生态水位，东荆河下游38.9 km河段断流；2022年干旱过程与典型干旱年相比，呈现出气象干旱达极值、水文干旱创极值、旱情发展快、骤旱特征明显等新特点。

Abstract: In the summer and autumn of 2022, the abnormally high temperature and drought event occurred in Honghu City with high intensity and long duration, which had a serious impact on the local social and natural ecosystem. To investigate the characteristics of the drought hazard and disaster-forming process, the historical drought process event database was established based on the objective identification and evaluation method of drought events based on the meteorological observation data of Honghu long sequence. Followingly, the extremeness and impacts of the drought in summer and autumn of 2022 were evaluated, by combining with the disaster census data of drought events in typical years. The results show that the drought process lasted for 139 days and the percentage of precipitation anomaly in the process reached −75.4%. The relative wetness index reached −0.79, and the drought intensity index reached 22.4. The comprehensive intensity level was “extremely strong”, ranking the first among 113 drought processes since 1961. In 2022, the combination of drought and abnormally high temperature in Honghu City and drought in the Yangtze River basin caused the relative humidity of farmland soil lower than 65% in most days during the drought process, and the surface water area of Honghu Lake reduced by nearly 10%. The water level of Luoshan Station on the Yangtze River declined to 1.5~3.3 m lower than the lowest water level in history, and the water level of Honghu Lake declined to the lowest in the same period since 2010, which was lower than the lowest ecological water level for many consecutive days. The river was cut off for 38.9 km at the lower reaches of Dongjing River. Compared with typical dry years, the drought process in 2022 presents some new characteristics, such as the meteorological and hydrological drought intensity ranked the first in history, and the development of the drought process were characterized by a flash drought with rapid rate.