Climate change characteristics of combined high temperature and drought events in the Three Gorges region during 1961—2022

Observed meteorological data including daily average temperature, maximum temperature, relative humidity, and precipitation data from 32 national meteorological stations in the Three Gorges region (TGR) from 1961 to 2022 were used to identify the compound high-temperature and drought events and further analyze the climate change characteristics. The results indicate that the compound high temperature and drought events in the Three Gorges region mainly occur from mid June to early September, with the peak occurring in mid August. About 60% of TGR stations experience compound high temperature and drought events each year, with the northern and western regions being high-risk areas. About 68% of single station compound high-temperature drought events have a duration of less than 4 days. In the past 62 years, the annual compound high temperature and drought days in most parts of TGR have shown an increasing trend; The scope of the annual maximum single day compound high temperature drought event show an increasing trend. About 78% of TGR stations showed an increasing trend in composite high temperature and drought intensity. The annual probability of regional combined high temperature and drought process occurring in the TGR is 48%.The frequency, duration, impact scope, high temperature intensity, drought intensity, and comprehensive intensity of regional compound high temperature and drought event have all shown an increasing trend. Since the 21st century, the extreme regional compound high temperature and drought events has significantly increased. Under the background of global climate warming, the compound high temperature and drought events in TGR are also becoming more severe, and the adverse effects on the operation of water conservancy projects need to be highly valued