Abstract: On the basis of extensive review of relevant literatures in China and abroad, we summarize and analyse the research progresses on three hot issues concerning two river-connecting lakes in the middle and lower reaches of the Yangtze River, namely, the Dongting Lake and the Poyang Lake. Such issues include: water and sediment transport law, erosion and deposition evolution law, and their impacts on flood/dry regulation function. We also put forward such aspects to be strengthened corresponding to the shortcomings of current research as follows: 1) the quantitative evolution mechanism of the two lakes under natural and human influences, including the evolution of the two lakes in the period of scarce data, identification of the impact of natural factors on the erosion/deposition of the two lakes, and the natural erosion/deposition of the two lakes in the period of intensified human activities, etc; 2) forecasting the trend of long-term and wide-range erosion and deposition of the two lakes, transforming from total sediment deposition forecast of the two lakes to prediction of spatio-temporal distribution pattern of sediment deposition; 3) indicative assessment of the impact of the evolution of the two lakes on flood/dry regulation function, including indicators characterizing the flood/dry regulation function of the lakes and their responses to different scouring and silting scenarios in the future.

Key words: lake evolution, erosion and deposition pattern, river-lake relationship, future evolution scenarios, effect of flood/dry regulation