LU Hongya, DU Jun, YUAN Lei, LIAO Jian
Variations in extreme climate events are more sensitive to climate change than the mean values, and so have received much attention. In this study, the features of ten indices of precipitation extremes over Mt. Qomolangma region in China were examined broadly based on daily precipitation data during the period of 1971-2012 from 5 meteorological stations. The methods of inverse distance weighted (IDW), 10-year smoothing average, linear regression, Mann-Kendall test and continuous wavelet transform were employed to delineate the rate of change, abrupt change points, statistical significance of the trends, and periodicity of extreme precipitation indices. It is found that spatially, the most extreme precipitation indices increase from west to east. In recent 42 years, the consecutive dry days (CDD), consecutive wet days and simple daily intensity index have increased, but the other extreme precipitation indices have decreased. Among them, the very wet day precipitation, extremely wet day precipitation and the annual total precipitation have presented a larger decreasing trend, with the rates of -5.74 mm·(10a)-1, -1.20 mm·(10a)-1 and -5.32 mm·(10a)-1, respectively, especially in the Nyalam station on the southern slopes. On the decadal scale, the maximum decreasing extreme precipitation indices were in the 2000s; on the 30 years scale, there was also a decreasing trend on. Except for CDD, the extreme precipitation indices were closely associated with annual precipitation in Mt. Qomolangma region. There were obvious periods of 3 to 4 years for all extreme precipitation indices, together with periods of 10 a, 12 a and 15 a. Additionally, it was found with abrupt change test that all extreme precipitation indices have not abrupt change.
