滇中引水工程水源区水沙关系及悬移质含沙量预测方法研究

Study on Relationship Between Water and Sediment and Prediction Method of Suspended Sediment Concentration in the Water Source Area of the Central Yunnan Water Diversion Project

滇中引水工程水源状况对供水至关重要,为全面了解工程水源区的水量和悬移质含沙量特性,分析悬移质含沙量未来情势,依据水源区石鼓水文站资料系列,基于水文随机分析、小波分析、Copula函数等方法研究石鼓站水与沙的变化趋势及周期规律、联合分布及相依变化情况,在此基础上提出一种悬移质含沙量模拟及预测模型。研究结果表明,石鼓站流量和悬移质含沙量的年际、年内分配不均匀;水沙组合的同现重现期最大、联合重现期次之、条件重现期最小,同步遭遇概率远大于异步遭遇概率;未来丰、平、枯水情景下的多年平均悬移质含沙量分别为0.639、0.597、0.562 kg/m^(3),较1955~2019年实测的0.586 kg/m^(3)分别增长了9.0%、1.9%、-4.1%,3种情景下悬移质含沙量均呈上升发展趋势。研究成果从水沙分析角度为滇中引水工程供水调度、含沙量预估等提供了决策依据。

The water source condition of the Central Yunnan Water Diversion Project is very important.In order to fully understand the water volume and the sediment concentration characteristics of suspended load in the project water source area and analyze the future situation of the sediment concentration of suspended load,based on the data series of Shigu Hydrological Station in the water source area,the methods of hydrological random analysis,wavelet analysis,Copula function were used to study the change trend and periodic law,joint distribution and dependent change of water and sand at Shigu Station.On this basis,a simulation and prediction model of suspended load concentration was proposed.The results show that the discharge and suspended load concentration at Shigu Station are unevenly distributed Interannual and within years;The co-occurrence recurrence period of the combination of water and sediment is the largest,followed by the joint recurrence period,and the conditional recurrence period is the smallest.The probability of synchronous encounter is much greater than that of asynchronous encounter;In the future,the average annual sediment concentration of suspended load under the wet,normal and dry water scenarios are 0.639 kg/m^(3),0.597 kg/m^(3)and 0.562 kg/m^(3),respectively,which are 9.0%,1.9%and-4.1%higher than the measured 0.586 kg/m^(3)from 1955 to 2019.The sediment concentration of suspended load under the three scenarios shows an upward trend.The research results provide a reliable decision-making basis for water supply scheduling and sediment concentration estimation of the Central Yunnan Water Diversion Project from the perspective of water and sediment analysis.