Study on drought trend in south China based on standardized precipitation evapotranspiration index
In recent years, drought in south China occurred frequently. In order to investigate the trend of drought in this region, the standardized precipitation evapotranspiration index （SPEI） and monthly precipitation and average temperature data from the representative 50 sites in South China during 1961 -2010 were used to analyze the drought trend, the space distribution of extreme drought events, the drought occurrence frequency and drought duration in the region during nearly 50 years. The results show that south China is meeting with a widespread drought trend. The most severe drought has occurred in the last 10 years. Based on the method of Mann - Kendall test, it is known that the average SPEI index of the region mutated from 1998. The most severe drought area is the southern and western parts of Guangxi Province and Hainan Island, while the drought trend in Guangdong Province is the lightest. The extreme increase subsequently drought event occurred scarcely during the 1970s, and extreme drought events significantly and the drought duration extended. Significant temperature rise and weak increase in precipiration in this region resulting in the increase in potential evapotranspiration, which is probably the main reason of the drought trend in South China. The fact indicates that SPEI is a good drought trend indicator under climate warming. In addition, the high frequency of occurrence of extreme drought events is partly attributed to the decreased frequency of precipitation events and the rainfall concentration in recent years.
NETL
NSTL
万方数据
维普
