Abstract:

Based on the meteorological drought composite index (MCI) that was implemented in the national drought monitoring operation system currently, the characteristics of dry and wet conditions and variations of a drought of 66 meteorological stations in Fujian province in the past 59 years were analyzed using Morlet wavelet and empirical orthogonal function (EOF) methods. The results show that Fujian has obvious climatic characteristics of wet and dry seasons with significant periodic oscillations of 6-8 years and 22 years. The variation of wet and dry seasons' period in mountainous inland areas is longer than that in coastal areas. At seasonal scale, each season is featured by multiple time scales and regional differences. The spatial variation has three typical modes, which reflect the differences in monsoon rainfall amount and topography. The spatial and temporal distribution of drought processes expressed by MCI is consistent with historical drought events. Autumn and winter (spring and summer) are the seasons with the highest drought frequency (strongest drought intensity) in Fujian province. The occurrence probability of drought processes in coastal areas at the south of Minjiang River Estuary is significantly higher than that in inland areas, and the occurrence probability of synchronous drought in the whole province is relatively less (12%).

Key words: EOF analysis, Meteorological drought composite index (MCI), Drought characteristics