Acta Geographica Sinica ›› 2017, Vol. 72 ›› Issue (9): 1645-1654.doi: 10.11821/dlxb201709009

• Orginal Article • Previous Articles     Next Articles

Characterization index for expressing the relationship between the Yangtze River and Poyang Lake based on the theory of energy

Jinyun DENG(), Shaoying FAN   

  1. Wuhan University State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan 430072, China
  • Received:2017-02-22 Revised:2017-06-30 Online:2017-09-30 Published:2017-10-12
  • Supported by:
    Key Program of National Natural Science Foundation of China, No.41331174;Science and Technology Planning Project of Jiangxi Province, No.20051BBG70044

Abstract:

The complicated relationship between the Yangtze River and Poyang Lake is the factor determining the exchange of water and sediment between them and has great influence on the water resources, flood control, navigation, and ecological environment of the entire region. Based on the theory of energy, this paper explains the principle of the river-lake relationship from a new perspective. By constructing a new index Fe, the authors were able to analyze the evolution of the relationship between the Yangtze River and Poyang Lake since the 1950s. The results indicate that the value of Fe shows an increasing trend, which means the river effect is weakening while the lake effect is strengthening. Operation of the Three Gorges Dam has an important impact on the river-lake relationship, which further weakens the river effect. The river effect increases slightly in the dry season but decreases significantly at the end of the flood period. In addition, the relationship between the Yangtze River and Poyang Lake may induce drought and flood disasters to some degree. Flooding is more likely to occur when flow from the five tributaries of the Poyang Lake is large and the Yangtze River blocking effect is strong. In contrast, drought is more likely to occur when flow from the five tributaries of the Poyang Lake is small, while the lake effect is strong. Meanwhile, the probability of drought in the Poyang Lake from September to October increases due to the impounding of the Three Gorges Reservoir.

Key words: Poyang Lake, Yangtze River, river-lake relationship, Three Gorges Dam, characterization index