特枯水情下青草沙水库取水保证程度研究

Study on water availability in Qingcaosha Reservoir under extremely low water conditions

在长江中上游多年水文观测资料及青草沙水域盐度监测资料分析的基础上,分析长江来水与沿江引排水的基本特征和变化趋势,定量研究长江大通水文站流量与青草沙水域盐度之间的关系,结果表明:大通站月平均流量大于3万m3/s时,青草沙水域月平均盐度接近或等于0;月平均流量小于2万m3/s时,平均盐度增加较快。提出特枯水情下青草沙水域取水保证率,为青草沙水库合理运行调度提供重要依据。

Based on the analysis of tong-term hydrological observation data from the mid- and upstream stretches of the Yangtze River and the information gained from salinity monitoring in the Qingcaosha water area, the basic characteristics and variation trend of the water from the Yangtze River and the draw and discharge of water along the fiver bank were analyzed. A quantitative study on the relationship between the discharge at the Datong Hydrological Station and the salinity in the Qingcaosha water area shows that when the monthly mean discharge at the Datong Hydrological Station was more than 30 000 m3/s, the corresponding monthly mean salinity in the Qingcaosha water area was close to or equal to zero, and, when the monthly mean discharge was less than 20 000 m3/s, the corresponding monthly mean salinity increased rapidly. The guarantee rate of water availability in the Qingcaosha water area under extremely low water conditions is put forward, providing an important basis for appropriate operation and dispatching of the Qingcaosha Reservoir.