**Appendix A**

**Figure A1.** Mean annual precipitation in the Shuaishui River Basin: 2009–2017. The error bar shows ± one standard deviation of the annual average precipitation among the 13 rainfall stations.

**Figure A2.** Mean monthly precipitation in the Shuaishui River Basin: 2009–2017. The error bar shows ± one standard deviation of the monthly average precipitation among the 13 stations.

**Figure A3.** Scatterplots between monthly rainfall gauge observations and satellite precipitation product estimates.

**Figure A4.** Scatterplots between daily rainfall gauge observations and satellite precipitation product estimates.

**Figure A5.** Spatial distribution of the annual categorical evaluation metrics at daily scale: (**a**) *POD*; (**b**) *FAR*; and (**c**) *CSI*.

**Figure A6.** Scatterplots between hourly rainfall gauge observations and satellite precipitation product estimates.

**Figure A7.** Spatial distribution of the categorical evaluation metrics (April to October) at hourly scale: (**a**) *POD*; (**b**) *FAR*; and (**c**) *CSI*.
