基于伴随同化法的一维河流水质模型参数反演  

Inversing Parameters of 1-D Stream Water Quality Model Using Adjoint Data Assimilation Method

作　　者：杨中华[1] 周武刚 白凤朋 安瑞冬[2] YANG Zhonghua;ZHOU Wugang;BAI Fengpeng;AN Ruidong(State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University ,Chengdu 610065 ,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065

出　　处：《应用基础与工程科学学报》2018年第2期276-284,共9页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(51379157,51439007,51679170)

摘　　要：本文利用伴随同化法研究了一维河流水质模型中污染源源强与纵向离散系数的反演问题.伴随同化法通过使模型计算值尽可能接近实测值即模型计算值和实测值的距离（目标函数）最小来反演最优模型参数,利用拉格朗日算子法将以模型方程作为约束条件的反演问题转化为无约束最优化问题,并利用最速下降法求解.在污染源源强反演算例中,利用河道一维瞬时污染源的解析解作为约束条件,开展了4个污染源源强反演的数值实验,采用不同组合源强初值进行反演计算均能取得较好的演算效果,验证了该方法对多参数的适用性以及对初始值的鲁棒性.纵向离散系数反演算例中,以河道上下游相邻断面的浓度关系为模型约束方程,采用Guymer（1998）示踪实验中得到的观测数据反演河道纵向离散系数,得到的纵向离散系数值比传统的演算法得到的结果更加准确.The adjoint data assimilation method minimized the objective function which defined as the difference value between simulation value and observation value to find the optimal parameters.Transform the inverse problem with constraint equation into unconstrained control variables optimization problem by the Lagrange operator method. Used the steepest descent method solve the control variables optimization problem. In the pollution source intension inversing case,the analytical solution of instantaneous source was treated as the model constraint equation to inverse four pollution sources intension with different initial emission intensities. The results indicates that the adjoint data assimilation method can find multi-variables successfully,with great robustness and applicability. In the longitudinal dispersion coefficient inversing case,the adjoint assimilation method was applied to predict the longitudinal dispersion coefficient based on the measured data of pollutants concentration by Guymer. The results of the adjoint data assimilation method agree better with the observed values compared with the results of the artificial trial method which Guymer used.

关 键 词：伴随同化 纵向离散系数 源强 反问题 水质模型 

分 类 号：K522[历史地理—历史学] X43[历史地理—世界史]