Characterizing the changing behaviours of precipitation concentration in the Yangtze River Basin, China

Authors

  • Weiguang Wang,

    Corresponding author
    1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
    2. College of Hydrology and Water Resources, Hohai University, Nanjing, China
    3. CSIRO Mathematics, Informatics and Statistics, Floreat Park, WA, Australia
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  • Wanqiu Xing,

    1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
    2. College of Hydrology and Water Resources, Hohai University, Nanjing, China
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  • Tao Yang,

    1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
    2. College of Hydrology and Water Resources, Hohai University, Nanjing, China
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  • Quanxi Shao,

    1. CSIRO Mathematics, Informatics and Statistics, Floreat Park, WA, Australia
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  • Shizhang Peng,

    1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
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  • Zhongbo Yu,

    1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
    2. College of Hydrology and Water Resources, Hohai University, Nanjing, China
    3. Department of Geoscience, University of Nevada Las Vegas, Las Vegas, NV, USA
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  • Bin Yong

    1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
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Abstract

The statistical characteristics of precipitation on the daily resolution play an important role not only in the risk assessment of floods and droughts but also in the land use management. In this study, spatial and temporal patterns of the precipitation concentration in the Yangtze River Basin are investigated by using three indices, i.e. precipitation concentration index (CI), precipitation concentration degree (PCD) and precipitation concentration period (PCP). Based on meteorological data of 147 stations for the period of 1960–2008, non-parametric trend analysis and wavelet transformation analysis are employed to detect the temporal variation of these indices. Spatial variability of precipitation concentration indices and their trends are analysed and demonstrated with the help of GIS tools. The results indicate the following: (i) The high precipitation CI values mainly distribute in the middle region of the Yangtze River Basin, whereas the lower and lowest CI values are found in the lower and upper regions, respectively. A roughly east–west gradient for PCD value and PCP value varies from 0.26 to 0.77 and from 123 to 197, respectively. (ii) The analysis results of precipitation CI trends for different periods (i.e. recent 40, 30 and 20 years) show that the middle region of the Yangtze River Basin experienced a transition from decreasing precipitation CI to increasing precipitation CI during the last two decades, although the decreasing long-term trends in the precipitation CI are not significant in most areas during the period of 1960–2008. (iii) The upper basin, middle basin and lower basin are, respectively, dominated by the significant decreasing, increasing and no significant trends in PCD. A dominance of insignificant PCP trends is observed in the entire basin during 1960–2008 despite that a few areas in the upper region are characterized by significant decreasing trends. (iv) Interdecadal oscillations can be found for three precipitation indices, but with no constant periodicity. Furthermore, good positive correlations have been detected between precipitation CI and PCD, whereas insignificant correlation coefficients of PCP with precipitation are common in the basin. The results can provide beneficial reference to water resource and eco-environment and mitigation to flood or drought hazards in the Yangtze River Basin for policymakers and stakeholders. Copyright © 2012 John Wiley & Sons, Ltd.

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