Changes in magnitude and frequency of heavy precipitation across China and its potential links to summer temperature

JOURNAL OF HYDROLOGY

卷:547

Article

Gu, Xihui¹  Zhang, Qiang^2,3,4  Singh, Vijay P.^5,6  Shi, Peijun² 

[1] Sun Yat Sen Univ, Dept Water Resources & Environm, Guangzhou 510275, Guangdong, Peoples R China

[2] Beijing Normal Univ, Key Lab Environm Change & Nat Disaster, Minist Educ, Beijing 100875, Peoples R China

[3] Beijing Normal Univ, Acad Disaster Reduct & Emergency Management, Beijing 100875, Peoples R China

[4] Beijing Normal Univ, Fac Geog Sci, Beijing 100875, Peoples R China

[5] Texas A&M Univ, Dept Biol & Agr Engn, College Stn, TX USA

[6] Texas A&M Univ, Zachry Dept Civil Engn, College Stn, TX USA

关键词: Heavy precipitation;    Change points (CPs);    Trend analyses;    Summer temperature;    China;   

DOI  :  10.1016/j.jhydrol.2017.02.041

来源: Elsevier

【 摘 要 】

Changes in the magnitude, frequency and timing of heavy precipitation are closely related to the occurrence of floods and droughts, which hold a great deal of significance for management of agricultural irrigation and water resources. Records of daily precipitation and temperature from 728 stations across China were used to assess changes in the magnitude, frequency and timing of heavy precipitation using the Peak-over-Threshold (POT) with 95th percentile as the threshold. Because of the continuous nature of the magnitude and timing of heavy precipitation, the change point method and the modified Mann-Kendall trend test method were used to detect change points (CPs) and slowly-varying changes, respectively. In addition, the segmented regression and Poisson regression methods were used to detect CPs and temporal trends in the frequency of heavy precipitation, respectively, with consideration of the count nature of the data. The results showed that 55% and 36% of the stations had CPs in mean and/or variance of the magnitude and timing, respectively, while the percentage is only 5.8% in the frequency. However, while there is limited evidence of significant trends in the magnitude and timing, strong evidence points to a significant increasing frequency in most regions of China. These changes may be partly explained by changes in summer temperature. Examination of the summer surface temperature records suggests that the areas, where the frequency of heavy precipitation has a significant increase, are also mostly characterized by significant increasing temperature. In addition, trends of the frequency vary between the periods before and after the turn point (TP) of summer temperature trends, especially in northern China where both the summer temperature and the frequency have shifted significantly decreasing trends to significantly increasing trends. A possible interpretation of these findings is that storms tend to be more frequent without significant changes in water vapor content. (C) 2017 Elsevier B.V. All rights reserved.

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