Fig. 1 Distributions of summer (JJA) total precipitation (a), Q index (b), and their linear trends (c, d) in South China for 1961-2010. The trends with cross signs are significant at the level of p < 0.1

Fig. 2 Time series of total summertime precipitation amount (bars) and the Q index (curve) averaged over the entire South China (a), the north of South China (b), and the south of South China (c) from 1961 to 2010. The dashed lines represent linear regression trend

Fig. 3 (a) Percentages of the occurrence of different wet spells (solid bars, bottom x-axis) and of the fractional contribution of different wet spells to the total number of wet days (hollow bars, top x-axis), (b) temporal evolution of the normalized anomalies in fractional contribution of different wet spells to the total number of wet days smoothed with a 5-year running mean, and (c) linear trends (% per decade) in the fractional contribution of wet spells to wet days in South China during 1961-2010

Fig. 4 Trends in total wet days (a), wet days from short wet spells (b), and wet days from long wet spells (c) in South China during 1961-2010 summer. The trends with cross signs are significant at the level of p < 0.1

Fig. 5 The same as Fig. 3, but for the wet spell with daily precipitation amount≥ 25 mm

Fig. 6 The same as Fig. 4, but for the wet spell with daily precipitation amount≥ 25 mm

Fig. 7 The same as Fig. 3, but for the wet spell with total precipitation amount≥ 50 mm

Fig. 8 The same as Fig. 4, but for the wet spell with daily precipitation amount≥ 50 mm