Characteristics of Annual and Seasonal Precipitation Variation in the Upstream of Minjiang River, Southwestern China

Abstract

Characteristics of annual and seasonal precipitation variation are explored in the upstream of Minjiang River (UMR), Southwestern China, spanning from 1960 to 2015. The moment of method (MOM), linear regression method, Mann–Kendall test, sequential cluster analysis, and Morlet wavelet analysis were utilized. The results clearly show the following: (1) Distribution of precipitation is uneven in space, with more in the south and less in the southeast. Decade average of annual precipitation reached the lowest in the 2000s and increased during 2010–2015 at all gauging stations and UMR. (2) Areal annual precipitation exhibited an insignificant decreasing trend with a rate of 4.47 mm/10a, which was mainly attributable to decreased summer precipitation. Spring precipitation exhibited an insignificant increasing trend and winter precipitation remained unchanged. (3) The change points mainly appeared in the 1980s and 1990s. And the almost periods of study area were generally 2–5 years, 7–11 years, and 15–20 years. (4) The increasing trend of annual precipitation is relatively obvious at higher altitudes, while the decreasing trend is more significant at low altitude stations.