卡尔曼滤波与土壤水数值模型耦合推求渗透系数  

Determination of the coefficient of permeability based on Kalman filtering coupled with numerical model of soil moisture

作　　者：温鲁哲[1] 陈喜[1] 魏玲娜[1] 凌敏华[1] 张志才[1] 

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,南京210098

出　　处：《工程勘察》2010年第4期34-38,共5页Geotechnical Investigation & Surveying

基　　金：教育部科学技术研究重大项目(308012);国家自然科学基金项目(50679025)资助

摘　　要：本文采用非饱和土壤水数值模拟结合卡尔曼滤波实时校正技术推求饱和渗透系数,根据饱和渗透系数在强降雨期、无雨或小降雨期的变化,发现在强降雨期土壤中形成自由水后农田作物根系等大孔隙显著增大饱和渗透系数现象。以田间持水量作为控制条件,提出强降雨期采用土壤基质和大孔隙介质等效饱和渗透系数,可以有效地提高土壤水运动数值模拟的精度。本文选择安徽省五道沟水文实验站1997～1998年逐日土壤水含水率观测资料,进行参数率定,分析强降雨期大孔隙对分层土壤含水率计算的影响程度,采用1999～2000年土壤含水率观测资料,进行模型验证。结果表明,在有降雨及土壤含水率观测资料地区,采用该方法可以有效地推求大孔隙介质渗透系数及土壤基质和大孔隙介质等效渗透系数。The saturated coefficient of permeability is calculated based on the numerical simulation of unsaturated soil water and Kalman filtering in the real-time correction technique. According to the change of the coefficient in the heavy rainfall period,no-rain period or weak rainfall period,the phenomenon that the significant increase of the coefficient is formed after the formation of the free water in the soil in the heavy rainfall period because of the macropores which are composed by the crop root system is identified. In order to enhance the accuracy of the numerical simulation,the concept of the integrated saturation coefficient of permeability which is consisted of soil matrix and macropore medium is presented,while taking the field capacity as the control condition. The parameter calibration is made with the observed data of the soil moisture from the hydrologic experimental station in Wudaogou from 1997 to 1998,and the data in 1999 is adopted to verify the layered computational efficiency under considering and not considering macropores. The results show that the said method is not only feasible in the calculation of the saturated coefficient of permeability in macropores,but also better in improving the numerical simulation accuracy of soil moisture.

关 键 词：土壤水 数值模拟 卡尔曼滤波 大孔隙 渗透系数 

分 类 号：P641.2[天文地球—地质矿产勘探]