关键词: 江湖关系，洪水遭遇，模型，实验

Abstract: Chenglingji is located in the confluence of Yangtze River′s main stream and Dongting Lake′s outflow. In addition to the deposition of bed level and flood characteristics, the flood combination of Dongting Lake′s outflow and Yangtze River′s main stream is also a very important factor which affects the flood level. We studied the change of Chenglingji crosssection water level under different conditions including different flood composition, different discharge and different water levels of Luoshan by model experiment. The result shows: in Chenglingji crosssection, when inflow of Jianli exceeds outflow of Dongting Lake, threads of steam are close to left side bank; when inflow of Jianli is below outflow of Dongting Lake, threads of steam close to right side bank. The flood combination of Dongting Lake′s outflow and Yangtze River main stream′s inflow affect heavily the water level of Chenglingji crosssection. When inflow of Jianli takes about 55 percent of Luoshan′s discharge, water level of Chenglingji crosssection is highest at that time, that is, the amplitude of setup of Yangtze River main stream′s inflow and Dongting Lake′s outflow consumes energy at maximum value. In middle water discharge, when inflow of Jianli takes about 55 percent of Luoshan′s discharge, water level differences of both banks reaches minimum in Chenglingji crosssection.

Key words: relationship of Yangtze River and Dongting Lake, flood flow combination, model, experiment