水利学报2015，Vol.46Issue(12)：1470-1478,1486,10.DOI:10.13243/j.cnki.slxb.20141225
非饱和土壤水的集合卡尔曼滤波Ⅱ:不一致性问题解决方法比较
Ensemble Kalman filter for unsaturated soil water flowⅡ:Comparison of methods to deal with inconsistency
摘要
Abstract
Ensemble Kalman filter (EnKF) can easily improve the soil water prediction by incorporating measurement information,but it may cause inconsistency in non-linear problems. In this paper,inconsisten?cy is defined as that parameters and pressure head are no longer subject to Richards' equation when they are updated simultaneously. Based on the hydraulic conductivity data in Borden experimental site,a synthet?ic soil column experiment is constructed to investigate the potential damage from inconsistency and the itera?tive approaches to eliminate or alleviate inconsistency. The results show that in heterogeneous soil, EnKF may cause strong inconsistency, which damages the accuracy of soil water prediction and parameter estima?tion. The peak of inconsistency is consistent with the flow front and influenced by the boundary condition. In general, when using the same type of observations to estimate the same type of parameters, the greater the proportion of observation number to parameter number, the less the inconsistency. When the relation?ship between pressure head, soil moisture and the observations is strongly nonlinear, we propose CEnKF or MREnKF algorithm which can effectively reduce the influence of inconsistency with low cost. When the observation information is relatively abundant ,then the negative effects of inconsistency can be ignored,En?KF is advantageous.关键词
非饱和流/集合卡尔曼滤波/不一致性/迭代型方法Key words
unsaturated flow/ensemble Kalman filter (EnKF)/inconsistency/iterative method分类
农业科技引用本文复制引用
张秋汝,史良胜,林琳,杨楚慧..非饱和土壤水的集合卡尔曼滤波Ⅱ:不一致性问题解决方法比较[J].水利学报,2015,46(12):1470-1478,1486,10.基金项目
国家自然科学基金项目(51179132,51279141) （51179132,51279141）
