Acta Geographica Sinica ›› 2010, Vol. 65 ›› Issue (7): 828-840.doi: 10.11821/xb201007007

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Spatio-temporal Patterns of Sediment and Runoff Changes in the Poyang Lake Basin and Underlying Causes

SUN Peng1, ZHANG Qiang1,2, CHEN Xiaohong1, CHEN Yongqin David3,4   

  1. 1. Department of Water Resources and Environment, Sun Yat-sen University, Guangzhou 510275, China;
    2. Nanjing Institute of Geography and Limnology, Nanjing 210008, China;
    3. Department of Geography and Resource Management, The Chinese University of Hong Kong, Hong Kong, hina;
    4. Centre of Strategic Environmental Assessment for China, The Chinese University of Hong Kong, Hong Kong, China
  • Received:2010-01-11 Revised:2010-04-09 Online:2010-07-20 Published:2010-07-20
  • Supported by:

    National Science Foundation of China, No.40701015; Frontier Program of the Nanjing Institute of Geography and Limnology, CAS, No.CXNIGLAS200814; No.08SL141001-28005; The Program for Outstanding Young Teachers of the Sun Yat-sen University, No.2009-37000-1132381; The '985 Project', No.37000-3171315; The Key Project of National Natural Science Foundation of China, No.50839005]

Abstract:

Annual runoff and annual suspended sediment loads at five hydrological gauging stations (Waizhou, Meigang, Lijiadu, Hushan and Datong) in the five tributaries of the Poyang Lake Basin (Ganjiang River, Fuhe River, Xinjiang River, Raohe River and Xiushui River) were analyzed using Mann-Kendall trend test and linear regression method. The results indicate that (1) the changing patterns of runoff and sediment loads are different over the Poyang Lake Basin. No significant trend is found for annual runoff at all the stations at >95% confidence level. However, the changes of sediment loads demonstrate different pictures in the Poyang Lake Basin. The sediment loads show a decreasing trend at Waizhou, Meigang and Hushan stations (the increasing trend of Waizhou station is significant at > 95% confidence level after around the year 1998), but an increasing trend at Ljiadu and Xiushui stations; (2) the forest coverage changes have greater impacts on sediment load than on the runoff; extensive deforestation contributed less to the increase of sediment loads in 1958. Large-scale deforestation caused significant increase of sediment loads during 1971-1985; (3) Hydraulic facilities, especially water reservoirs, exerted more influences on sediment load changes than on runoff, being the major cause next to the decreasing trend of sediment loads. The results of this study are of great practical significance to a better understanding of the hydrological responses to climate changes and human activities across the Poyang Lake Basin, as a freshwater wetland in China.

Key words: Poyang Lake Basin, runoff and sediment changes, water reservoir, Mann-Kendall trend