冲积河流过程水沙输移模型不确定性分析及数据同化方法研究

项目名称： 冲积河流过程水沙输移模型不确定性分析及数据同化方法研究

项目编号： No.51309254

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 水利工程

项目作者： 冶运涛

作者单位： 中国水利水电科学研究院

项目金额： 25万元

中文摘要： 冲积河流水沙模型输入数据误差和模型参数不确定性是制约模型精度提高的主要瓶颈。本项目针对目前水沙模型模拟计算精度低、参数率定困难等不足，结合水沙模型特点，引入集合卡尔曼滤波技术探索建立水沙运动观测和机理模型高度融合的冲积河流水沙模型数据同化理论和方法，从而系统地降低模型的不确定性和提高水沙过程模拟精度。本项目拟以二维水沙模型为研究对象，定量分析输入条件和模型参数对水沙模型不确定性的影响；建立基于改进集合卡尔曼滤波的水沙输移数据同化模型；分析集合规模、观测数据类型、观测位置和频次等各种因素对数据同化效果的影响规律；研究基于数据同化的水沙模型参数和状态变量联合估计方法；最后，将该方法理论应用于实际溃坝洪水过程和天然河道水沙过程的参数时空变化规律分析及水流泥沙过程的模拟。项目研究成果不仅有助于解决参数率定困难和降低模拟结果不确定性问题，而且有利于深刻地认识水沙运动规律以及水流与泥沙相互作用机理。

中文关键词： 水文模型；水沙模型；数据同化；集合卡尔曼滤波；不确定性分析

英文摘要： The accuracy of the water-sediment transport model is mainly affected by the uncertainties resulted from the model input data and the determination of model parameters. In order to improve the accuracy of the model, the proposal introduces a data assimilation method of the two-dimensional water-sediment transport model by the use of the Ensemble Kalman Filter (EnKF) . The proposal firstly analyzes the model uncertainty caused by input errors and the parameter errors quantitatively. And then a data assimilation model for water-sediment mathematical model is presented to reduce the model uncertainties, and the rules of affecting on the data assimilation model by the various factors including, the ensemble size, the type of the observation data, the observating frequency and its observation location, et.al., are analyzed. Based on the data assimilation model, combined with the state augmentation technique and iterative technique respectively, two methods of estimations for the parameters and state variable of the water-sediment mathematical model are proposed and differences between them are found out through the data from sketch model experiment. We tentatively apply the methods in simulating fluvial river processes and predicating flood. The output of the research results are not only helpful to solve the difficu

英文关键词： hydrological model；water-sediment model；data assimilation；ensemble kalman filter；uncertainty analysis