城陵矶洪水位抬高原因分析

近50年来城陵矶站年最高洪水位累计抬高了约1.5m，通过一维非恒定流数学模型研究说明，城陵矶至汉口河段淤积只抬高了洪水位约0.2～0.3m，不是城陵矶洪水位抬高的主要因素。通过理论探讨和实测资料分析说明，由于洞庭湖容积减小等因素影响，近50年来螺山水文站年最大日平均流量累计增大了约7000m3/s，抬高洪水位约1.2m，是洞庭湖区洪水频率增加和城陵矶洪水位抬高的主要因素，在制定长江中游和洞庭湖区防洪规划时应加以考虑。

Analysis on causes of water level rising at Chenglingji Hydrological Station of Changjiang River

The Chenglingji Hydrological Station located at the outlet of the Dongting Lake. The water level at this station rises about 1.7m in the recent 50 years. The causes of this rising are analyzed by using a 1-D mathematical model for unsteady flow. It is found that the major factor affecting the water level rising is the reduction of the water volume stored in the Lake. Due to the volume reduction the annual average daily discharge at the Luoshan Station increases by 7000m3/s resulting in the rising of the water level about 1.2m. The water level rising resulted from deposition taken place in the river section from Chenglingji to Wuhan is in the range from 0.2m to 0.3m only.