Annual and seasonal changes in means and extreme events of precipitation and their connection to elevation over Yunnan Province, China

Abstract

Based on daily precipitation records at 29 meteorological stations over Yunnan province, the spatial and temporal changes in precipitation index are analyzed during 1960–2013. Eleven indices of precipitation extremes are studied. The results show that regional annual total precipitation shows a significantly decreasing trend and most other precipitation indices are strongly correlated with annual total precipitation. Seasonally, a significant increase in precipitation was discovered for spring, while a decrease in precipitation was found for winter, summer, and autumn. Two significant decreasing trends are found for summer and autumn. Average consecutive dry days, number of heaviest precipitation days, very wet day precipitation, extremely wet day precipitation, maximum 1-day precipitation and simple daily intensity index show increasing trends, but only the last is statistically significant. Decreasing trends are found for consecutive wet days, wet day precipitation, number of heavy precipitation days, number of very heavy precipitation days and maximum 5-day precipitation, but only the first is significant at the 95% level. Spatial changes of precipitation extreme indices show differences, and they are not clustered. For maximum 1-day and 5-day precipitation, the spatial and temporal changes in monthly precipitation are not the same. There are no significant correlations between elevation and trend magnitude of precipitation extremes. An enhanced sensitivity of precipitation extremes at higher elevations is apparent.