基于时间序列的朱沱和寸滩水位变化特征分析

Characteristics of Water Level Variation at Zhutuo and Cuntan Stations Based on Time Series Analysis

长江上游水位变化对防洪和航运等具有重要意义.本文基于朱沱和寸滩水文站近60年水文资料分析水位流量关系变化以及寸滩站受三峡回水影响的临界条件,并研究不受三峡回水影响下朱沱和寸滩的水位变化趋势以及三峡成库前后的水位变化幅度.结果表明:寸滩站受回水影响的临界流量随坝前水位增大而增大,当坝前水位大于163.5m时,寸滩站均受回水影响;近60年来朱沱站和寸滩站在不受三峡回水影响下,水位整体呈降低趋势;与三峡成库前相比,朱沱站和寸滩站水位累计降低幅度分别在2015年、2010年有趋势性增大,且随流量的增大而减小;朱沱站在2018年4 000m^(3)/s时,水位累计最大降低幅度达0.7m, 20 000m^(3)/s时,降低幅度为0.4m;寸滩站在2018年6 000m^(3)/s时,水位累计最大降低幅度为0.75m, 20 000m^(3)/s时,降低幅度0.25m.研究结果可为长江上游航道建设及维护等提供参考.

Water level changes in the upper Yangtze River are important for flood control and navigation.Based on the hydrological data at the Zhutuo and Cuntan station in recent 60 years,this study analyzed firstly the changes of stage-discharge relationship and the critical flow conditions of Cuntan station affected by the Three Gorges Reserover(TGR)backwater,then investigated the variation trends and the specific changes of the water level after TGR operation.Results showed that the critical discharge affecting the Cuntan water level increased with the raising of the pre-dam water level,and the Cuntan water level were affected by the TGR backwater at all discharges when the pre-dam water level exceeded 163.5 m.Over the past 60 years,the water levels at Zhutuo and Cuntan stations without backwater affect had a decreasing tendency.Compared with the water level before the operation of TGR,the cumulative reduction of the water level at Zhutuo and Cuntan stations had an obvious increase in 2015 and 2010 respectively,and decreased with the increasing discharge.The maximum cumulative reduction of the water level at Zhutuo station was 0.7 m and 0.4 m in 2018 at 4000 m^(3)/s and 20000 m^(3)/s respectively,while that at the Cuntan station was 0.75 m and 0.25 m in 2018 at 6000 m^(3)/s and 20000 m^(3)/s respectively.The results can provide references for the construction and maintenance of the upper Yangtze River waterway.