Figure 4 Spatial
distribution of precipitation estimation parameters α , βfor 698 weather stations in China
As shown in Figure 4 . the gamma distribution is used to well
fit the estimated parameters α and β of PDC for 698
weather stations across China. The values of α , except for the
stations in the southwest and southeast inland regions of China
distributed above 0.6, is basically distributed between 0.2 and 0.6.
From Figure 4 (b), it can be found an increasing trend ofβ from northwest to southeast of China, and β is mainly
distributed between 0 and 10 in northwest China, and is mainly
distributed between 10-20 at stations in Northeast China, Central China,
and Yunnan Province, and is distributed between 20-30 in most areas in
the southeast, with a small number of coastal cities in the southeast
distributed between 30 and 70. From the figure, it is discovered thatβ shares a similar spatial distribution pattern with average
annual precipitation in China.