Abrupt changes in the discharge and sediment load of the Pearl River,China |
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| Authors: | Qiang Zhang Chong‐Yu Xu Xiaohong Chen Xixi Lu |
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| Institution: | 1. Department of Water Resources and Environment, Sun Yat‐sen University, Guangzhou 510275, China;2. Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education Institute, Sun Yat‐sen University, Guangzhou 510275, China;3. Department of Geosciences, University of Oslo, Oslo, Norway;4. Department of Geography, National University of Singapore, Arts Link 1, Singapore 117570 |
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| Abstract: | The abrupt changes in the streamflow and sediment load at nine hydrological stations of the Pearl River basin were systematically analysed by using the simple two‐phase linear regression scheme and the coherency analysis technique. Possible underlying causes were also discussed. Our study results indicated that abrupt changes in the streamflow occurred mainly in the early 1990s. The change points were followed by significant decreasing streamflow. Multiscale abrupt behaviour of the sediment load classified the hydrological stations into two groups: (1) Xiaolongtan, Nanning and Liuzhou; and (2) Qianjiang, Dahuangjiangkou, Wuzhou, Gaoyao, Shijiao and Boluo. The grouped categories implied obvious influences of water reservoirs on the hydrological processes of the Pearl River. On the basis of analysis of the locations and the construction time of the water reservoirs, and also the time when the change points occurred, we figured out different ways the water reservoirs impacted the hydrological processes within the Pearl River basin. As for the hydrological variation along the mainstream of the Pearl River, the water reservoirs have considerable influences on both the streamflow and sediment load variations; however, more influences seemed to be exerted on the sediment load transport. In the North River, the hydrological processes seemed to be influenced mainly by climate changes. In the East River, the hydrological variations tended to be impacted by the water reservoirs. The study results also indicated no fixed modes when we address the influences of water reservoirs on hydrological processes. Drainage area and regulation behaviour of the water reservoirs should be taken into account. The results of this study will be of considerable importance for the effective water resources management of the Pearl River basin under the changing environment. Copyright © 2011 John Wiley & Sons, Ltd. |
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| Keywords: | multiscale abrupt behaviour sediment load streamflow variations simple two‐phase linear regression model scanning t‐test the Pearl River basin |
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