Variability in the Extreme Precipitation on the Chuandian Plateau, China

Abstract

Extreme precipitation events can cause disasters, especially in areas with complex terrain. It is very important to identify whether the spatiotemporal distribution of extreme precipitation intensity over the Chuandian Plateau of China has changed. This paper selects five indices from the Expert Team on Climate Change Detection Indices that can reflect the extreme precipitation intensity. K-means clustering results in two distinct precipitation seasons. The spatial distribution and trends of precipitation are analyzed using daily quality-controlled data series from 20 meteorological stations from 1971 to 2015. The main results are as follows: (1) The extreme precipitation intensity increases from the north to the south of the region, with high-value areas in the southwestern and southeastern areas and low-value areas in the western and eastern areas. (2) The extreme precipitation intensity is higher, and the spatial differences are smaller during the wet season than during the dry season. The spatial variabilities in June and July are greater than those in August and September. The largest contributors to annual rainfall are the wet season and July. (3) The extreme precipitation intensity shows an increasing trend, especially in the central areas, even though the majority of the trends are not statistically significant. (4) The intensity of the extreme precipitation exhibits a relatively strong trend during the wet season and July, which could result in serious geomorphological disasters. It is critical to detect the characteristics and trends of extreme precipitation intensity-related disasters and develop appropriate adaptation and mitigation strategies.