Method for tracking four-dimensional soil moisture drought event and identifying warming signal

A method for tracking a four-dimensional soil moisture drought event and identifying a warming signal, comprising following steps:

• step S1, data acquisition:
• acquiring global climate data;
• step S2, identification of four-dimensional soil moisture drought events:
• calculating, in combination with the data obtained in the step S1, a 10th percentile of a soil moisture value during a growing season of a climatological period for each voxel as a drought threshold, identifying voxels for which soil moisture values are lower than the drought threshold as drought voxels, and identifying continuous four-dimensional soil moisture drought events by a Lagrangian four-dimensional tracking method;
• step S3, characteristic quantification of four-dimensional soil moisture drought events:
• calculating characteristics of soil moisture drought events in combination with the four-dimensional soil moisture drought events obtained in the step S2, and classifying the soil moisture drought events into surface drought and deep drought;
• step S4:
• anthropogenic warming signal detection based on temporal evolution of four-dimensional soil moisture drought characteristics in a historical period:
• performing anthropogenic warming signal detection on drought characteristic indicators calculated based on reanalysis data and historical climatic experiments of climate models by using a correlation coefficient method and an optimal fingerprint method in combination with duration and intensity characteristics of two types of drought events obtained in the step S3;
• step S5:
• estimation of future evolution of four-dimensional soil moisture drought:
• obtaining spatial-temporal evolution characteristics of drought events in a future period through the historical climatic experiments of the climate model and a future socio-economic development pathway experiment in combination with the duration and intensity characteristics of the two types of drought events obtained in the step S3;
• and obtaining spatial-temporal evolution characteristics of drought events under different vegetation types in the future period in combination with global land cover data obtained in the step S1;
• and
• step S6:
• attribution of four-dimensional soil moisture drought events to driving factors:
• attributing the two types of drought events to three early-stage driving factors according to data of near-surface air temperature, precipitation, and leaf area index obtained in the step S1 in combination with the duration and intensity characteristics of the two types of drought events obtained in the step S3, and quantifying contributions of different driving factors to the drought events.