Spatiotemporal Changes in Extreme Precipitation and Its Dependence on Topography over the Poyang Lake Basin, China

Xianghu Li,Qi Hu

doi:10.1155/2019/1253932

Abstract

Spatiotemporal changes in extreme precipitation at local scales in the context of climate warming are overwhelmingly important for prevention and mitigation of water-related disasters and also provide critical information for effective water resources management. In this study, the variability and trends of extreme precipitation in both time and space in the Poyang Lake basin over the period of 1960–2012 are analyzed. Also, changes in precipitation extremes with topography are investigated, and possible causes are briefly discussed. The results show that extreme precipitation over the Poyang Lake basin is intensified during the last 50 years, especially the increasing trends are more significant before the end of the 1990s. Moreover, high contribution rates of extreme precipitation to the total rainfall (40–60%) indicated that extreme precipitation plays an important role to the total water resources in this area. The precipitation extremes also exhibited a significant spatial dependence in the basin. The northeastern and eastern areas are exposed to high risk of flood disaster with the higher frequency of extreme precipitation events. In addition, the distribution of precipitation extremes had a clear dependence on elevation, and the topography is an important factor affecting the variability of extreme precipitation over the Poyang Lake basin.

Highlights

One aspect of the changing climate is change in extreme weather and climate events at regional and global scales [1, 2]
Asadieh and Krakauer [11] evaluated trends in global daily precipitation extremes and found that 66.2% of their studied grid cells show a positive trend during the past 110 years in South America, Australia, and India, 18% of which are statistically significant at the 95% confidence level
We extend the previous findings regarding the spatiotemporal changes in precipitation extremes and examine the role of the orography of the lake basin in precipitation extremes

Summary

Introduction

One aspect of the changing climate is change in extreme weather and climate events at regional and global scales [1, 2]. It is seen that all correlation coefficients (r) between the extreme precipitation indices and elevation have high year-to-year variability, with r ranging from −0.24 to 0.39 for EPD, −0.20 to 0.62 for EPA, −0.35 to 0.60 for EPI, −0.30 to 0.38 for EPR, −0.25 to 0.39 for CWD, −0.52 to 0.14 for CDD, −0.25 to 0.74 for Rx1d, and −0.32 to 0.77 for Rx5d.

Results

Conclusion