Spatial and temporal characteristics of extreme precipitation in Ganjiang River Basin in the past 50 years

The annual maximum (AM) and peak over threshold (POT) series were used to estimate the spatial and temporal characteristics of extreme precipitation over the past 50 years in Ganjiang River Basin based on the daily precipitation data from 13 hydrometric stations. In this study, four extreme precipitation indices including daily maximum precipitation (RX1), extreme precipitation (R95), extreme precipitation days (RD95) and extreme precipitation intensity (RI95) were analyzed by using the Mann-Kendall test and the Pettitt test. In addition, the ordinary Kriging was used to interpolate the extreme precipitation at each rainfall station and the spatial distribution of each index was summarized. The results show that the RX1, R95 and RD95 have a certain increasing trend, while RI95 has not changed much. There are no significant mutations in all four indices during the past 50 years. Spatially, RX1, R95 and RI95 show an increasing trend across the Ganjiang River from southwest to northeast, while spatial distribution of RD95 is irregular and exhibits several extreme centers.