近期南京潮水位站高流量级下水位流量特性研究

三峡工程运行已有十余年,大通水文站流量、径流量资料统计表明,三峡水库蓄水以来汛期平均最大流量减小8.4%,年径流量减小5.0%;南京潮水位站资料表明,三峡水库蓄水以来年最高平均水位降低了12cm,水位相对降低幅度明显小于流量降低幅度,南京潮水位站高流量下水位与流量关系出现倒挂。通过对1950年以来南京潮水位站的日平均最高水位、日平均最大流量及年径流量的变化进行统计分析,发现平滩流量以上南京潮水位站水位发生趋势性壅高,幅度为2.65 cm。南京潮水位站流量及径流量数据为同步大通水文站数据考虑区间支流入汇及积水面积增加所得,分析结果可为南京市防洪安全、水资源开发利用提供依据。

Characteristics of water level and flow at high tide discharge level at Nanjing tide station since impoundment of Three Gorges Reservoir in recent years

Three Gorges Project has been running for more than ten years. According to the statistical data of Datong Hydrometric station, the average maximum flow in flood season has been reduced by 8.4%, and the annual runoff has been reduced by about 5% since the impoundment of Three Gorges reservoir. According to the data of Nanjing tide station, the highest annual average water level has been reduced by 12cm since the impoundment, so the relative decrease of water level is obviously smaller than that of flow reduction, demonstrating that the relationship between water level and flow at high discharge at Nanjing hangs upside down. Based on the statistical analysis and correlation analysis of the daily average maximum water levels, daily maximum flows and annual runoffs of Nanjing tide station since 1950, we find that Nanjing tide station water level increases generally when level is higher than river beach elevation, and the amplitude is 2.65cm. The flow and runoff data of Nanjing tide station are the synchronous data of Datong hydrological station plus the lateral inflow. The results can provide basis for flood control and water resources development and utilization in Nanjing.