Fig. 4

(a) Comparative analysis of the values of the Standardized Precipitation Anomaly Index (SPAI) on the Y-axis (negative magnitude indicates water deficit while positive magnitude indicates water sufficiency and thus not shown) and with different SPAI-3 values [(SPAI-3)-1, (SPAI-3)-2, (SPAI-3)-3, and (SPAI-3)-4] on X-axis; (b) The number of meteorological drought events with different drought types for the observed period, i.e., 1982–2023 (For the findings on agricultural, hydrological, and environmental drought events, refer to the supplementary file’s Figs S1 to S6).