Drought and extreme heat events have serious societal and environmental impacts that are greatly amplified when both events occur simultaneously.In this paper,the standardized precipitation evapotranspiration index(SPEI)and standardized temperature index(STI)were calculated by using the gridded monthly precipitation and temperature data from 1961 to 2020.Based on the definition of composite events,the spatial and temporal evolution characteristics of composite high temperature and drought events in Northeast China under different dry heat thresholds were analyzed,and the spatial correlation of compound events was explored.The results showed that the frequency of CHDEs in Northeast China is low in the east and southeast and high in the west and northwest.During the study period,the historical evolution of the CHDEs found that Mi-Mi increased at a rate of 0.02/a,and increased significantly after the 1990 s.The impact area of the overall CHDEs types showed a significant upward trend,with a range of 1.02％/a.The area affected by different types of CHDEs increased significantly and peaked in the 1990 s.The high frequency areas of the compound events are concentrated in the west and northwest,with the low frequency areas concentrated in the southeast and east.The research results provide a reference for disaster prevention and mitigation,agricultural planning,and water resource allocation in Northeast China.
Compound heat and drought eventsSpatiotemporal characteristicsSpatial autocorrelationSPEISTI
NETL
NSTL
维普
万方数据
