长江中下游平原2022年高温干旱复合型极端事件的影响因子分析OA北大核心CSTPCD

Drought poses a significant threat to economic and agricultural development,impacting physical health and daily life.With global warming,heatwaves,and droughts,extreme events are occurring with increasing fre-quency,exacerbating disaster risks.The middle-lower Yangtze Plain,one of China's most densely populated,eco-nomically developed,urbanized regions,experienced the most severe heatwave and drought-compound extreme e-vent since 1961 in 2022.This event significantly impacted energy supply,agricultural production,and the ecosys-tem.This study analyzes precipitation and evaporation characteristics during the flood season from 2000 to 2022,exploring the mechanism and evolution of the 2022 extreme drought event in the middle-lower Yangtze Plain.A comparison with the high-temperature and drought events in 2013 provides a deeper understanding of the relation-ship between high temperatures and extreme drought in this region.The hydrological drought index,net precipitati-on(precipitation minus evapotranspiration,P-E)is used to analyze the drought conditions.Using ERA5 and ERA5-LAND reanalysis data,changes in P-E are decomposed into dynamic,thermodynamic,and transient eddy componentsby analyzing the moisture flux budget.Surface temperature during the 2022 flood season increased by nearly 1 ℃ compared to the 20-year average(2000-2019),with temperatures rising over 2 ℃ from July to Au-gust.Precipitation during the flood season decreased by 37％and by 45％from July to August,respectively,com-pared to the average for the same period.Net precipitation analysis indicates that the drought was primarily caused by decreased precipitation in the early flood season(May-June)of 2022.Moisture flux budget decomposition shows that changes in transient eddy and mean circulation were major contributorsto the early drought.In the mid-period(July-August),high temperatures enhanced surface evapotranspiration,especially in bare soil,worsening the drought.The thermodynamic contributionfrom increased specific humidity,driven by temperature rise,was the greatest factorin drought intensification.In the later period(September-October),high temperatures further altered the average circulation,with the dynamic component extending the drought duration.In contrast,the 2013 high-temperature and drought event was initially dominated by thermodynamic contributions,with mean circulation and transient eddy changes intensifying the mid-period droughtand only thermodynamic contributions remaining later,resulting in shorter duration and weaker drought severity.This analysis of the 2022 heatwave and drought com-pound extreme event development and evolution in the middle-lower Yangtze Plain provides a reference for pre-dicting and warning about high-temperature and drought extreme events in humid areas.In-depth research on these development and evolution events can improve regional drought event prediction and duration forecasting.