Acta Geographica Sinica ›› 2004, Vol. 59 ›› Issue (2): 239-248.doi: 10.11821/xb200402010

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The Response of Environment System Changes of Dongting Lake to Hydrological Situation

LI Jingbao1, QIN Jianxin1, WANG Kelin2, LIANG Chengjun1, YUAN Huabin3   

  1. 1. College of Resources & Environment, Hunan Normal University, Changsha 410081, China;
    2. Institute of Subtropical Agricultural, CAS, Changsha 410125, China;
    3. Hunan City College, Yiyang 413000, China
  • Received:2003-08-28 Revised:2003-12-10 Online:2004-03-25 Published:2004-03-25
  • Supported by:

    Knowledge Innovation Project of CAS, No.KZCX2-SW-415

Abstract:

To fu1ly reveal the water abnormity and its formative causes in Dongting Lake during recent decades, this paper takes Dongting Lake as a big system. Researches through a variety of methods such as the relation between water-level and runoff show: (1) The runoff on the same water-level reduces 1200 m3/s-2800 m3/s in the lower reaches of the four rivers flowing into the lake, the water-level with the same runoff runs up 0.49 m-1.28 m; (2) The dividing-water ratios of the three bayous of the Jingjiang River reduces by 19.2%, and the dividing-sand ratios 25.1%; (3) Great changes have taken place in the relation between water-level and runoff in the main flooding roads such as Li River, Songzi and southern Dongting Lake etc.; (4) The natural regulation and storage capacity fall off by 40%, the water-level with the same runoff at the bayous drives up 1.80 m-2.50 m; (5) The relation between lake and protective embankment is often at hazard during the period of July and August. The main reason is that the filling-up of mud-sand arises a vicious circle which leads to environmental function changes of the lake system, and the water-sand adjustment from the three curve-cuttings on the lower reaches of Jingjiang River accelerates the change process.

Key words: Dongting Lake, water-level &, runoff, sediment deposition, hydrological response