Temporal-spatial and non-stationarity characteristics of extreme precipitation in the Poyang Lake Basin, China

Abstract

Extreme weather/climate events increased significantly because of global warming. Based on daily records from 16 meteorological stations in the Poyang Lake Basin (PLB) from 1959 to 2019, we comprehensively investigated the temporal-spatial and non-stationarity characteristics of extreme precipitation from three dimensions (intensity, frequency and duration) using PreWhite-ning Mann-Kendall (PWMK), extreme-point symmetric mode decomposition method (ESMD) and the generalized additive models for location, scale and shape (GAMLSS). The results showed that the intensity and frequency of extreme precipitation increased significantly in the PLB, while the duration of extreme precipitation decreased from 1959 to 2019. The extreme precipitation had features of high intensity, high frequency, and short duration in the PLB. There was a clear distinction between flood season and non-flood season for extreme precipitation. Extreme precipitation was concentrated in the northern and central PLB during the flood season and in the central PLB during the non-flood season. The increasing trend of extreme precipitation amount was 2.10 mm·a-1 in the Xinjiang basin, which had the largest increment over the PLB. In the flood season, the extreme precipitation had longer duration but weaker intensity and smaller range, contrasting with the status during the non-flood season. The intensity and frequency of extreme precipitation showed stationarity characteristics in the PLB. However, the duration of extreme precipitation showed non-stationarity characteristics. With the continuous increase of extreme precipitation amount, the risk of related disasters would increase.