Spatiotemporal Variability of Extreme Summer Precipitation over the Yangtze River Basin and the Associations with Climate Patterns

Zhenkuan Su,Qing Cao,Feifei Yuan,Xi Chen,Zhenchun Hao

doi:10.3390/w9110873

Abstract

Understanding the spatiotemporal variability of seasonal extreme precipitation and its linkage with climate patterns is of great importance for water resource management over the Yangtze River Basin. Hence, this study examined the spatiotemporal variability of seasonal extreme precipitation through the archetypal analysis (AA), by which observations were decomposed and characterized as several extreme modes. Six archetypes were identified and can obviously exhibit the features of events with above average or below average precipitation. Summer precipitation is the most variable compared to the winter, spring, and autumn precipitation through the trend analysis. It ranged from extremely dry (A6) to normal (A1 and A2) to extremely wet (A4). Climate teleconnections to the four archetypes for summer precipitation and relative importance of climate patterns were thus investigated. Results show that El Niño Southern Oscillation index is the strongest determinant of the ensuing archetypes representing the events with above average precipitation, while the Atlantic Multi-decadal Oscillation (AMO) contributes most to the events with below-average precipitation. A warm phase of the Pacific Decadal Oscillation (PDO) is significantly correlated with the above-average precipitation.

Highlights

The Yangtze River is the longest river in China, extending from the Tibetan Plateau to the East China Sea, about 6300 km long (Figure 1)
Drought-flood abrupt alteration and continuous droughts that cross seasons are increasingly frequent over the Yangtze River Basin
We investigated the correlations of the summer archetypes and the four El Niño Southern Oscillation (ENSO) indices

Summary

Introduction

The Yangtze River ( known as Changjiang) is the longest river in China, extending from the Tibetan Plateau to the East China Sea, about 6300 km long (Figure 1). The basin climate is characterized by complex patterns of precipitation and subject to periodic flood and drought events throughout history [1,2]. Precipitation variability both in space and time can impact the uneven distribution of water resources [3], and the induced extreme events have caused severe economic losses and casualties [1,4,5]. Drought-flood abrupt alteration and continuous droughts that cross seasons are increasingly frequent over the Yangtze River Basin. Analyzing the spatiotemporal variability of extreme precipitation events in the Yangtze River Basin is highly important

Methods

Results

Discussion

Conclusion