Fig. 1. Location of the MLRYRB and distribution of meteorological stations

Fig. 2. SPI time series calculated from the TRMM 3B43 data (blue and red shaded bars) and station data (solid line) at different time scales: (a) 1 month; (b) 3 months; (c) 6 months; and (d) 12 months

Fig. 3. Correlation coefficients of the SPI values calculated with the TRMM 3B43 products and the weather station data

Fig. 4. Spatial distribution of the SPI value trends at the 3-month time scale in the MLRYRB

Fig. 5. Temporal variability in the SPI values and the drought events of different severity grades from 1998-2016

Fig. 6. Frequency of drought events and different drought levels (moderate drought, severe drought and extreme drought) based on the SPI values at the 3-month time scale in the MLRYRB from 1998 to 2016

Fig. 7. Temporal evolution based on the TRMM 3B43-derived SPI values for different drought conditions (moderate, severe and extreme) at different time scales (1, 3, 6 and 12 months)

Fig. 8. Spatial pattern of typical drought events based on the SPI values during the period of 1998-2016

Fig. 9. SPI time series calculated from the TRMM 3B43 data (blue and red shaded bars) and station data (solid line) based on the 56-year time series at different time scales

Fig. 10. Correlation coefficients for SPI values calculated with the TRMM 3B43 product and station data based on the 56-year time series