单环入渗试验广泛应用于野外测定土壤水力参数。文章在三维非饱和带水分模拟程序VSF基础上,加入了单环入渗水流计算模块,并将改进的VSF与参数优化程序LEVMAR相耦合,构建了适用于单环入渗试验的土壤水力特征参数反演程序VSF—LEVMAR。利用大型室内土槽单环定水头入渗及变水头入渗试验资料,反求水平及垂向饱和入渗系数等土壤水力参数。应用结果表明:该方法既可以利用单环定水头入渗试验单独推求吸湿过程中的土壤水力参数,也可以结合单环定水头入渗与变水头入渗试验同时推求吸湿及脱湿过程中的土壤水力参数。
Field infiltration experiment of a single ring permeameter is widely used for measuring soil hydraulic parameters. In this study, the 3-dimensional numerical model of unsaturated zone soil moisture (VSF) is improved by coupling the modular of the infiltration water from the single ring permeameter. The improved VSF was integrated with the optimization program (LEVMAR) to produce an inverse model (VSF-LEVMAR) for soil hydraulic parameter optimization. The infiltration experiments of fixed water head and variable water head within the ring permeameter are conducted in the indoor trough. The observation data are used to optimize soil hydraulic parameters, such as horizontal and vertical hydraulic conductivities. The study results indicate that the proposed method can be used to determine hydraulic parameters during the soil wetting period on the basis of infiltration experiments of fixed water head, and hydraulic parameters during the soil wetting and dry periods by integrating observation data from experiments of fixed and variable water heads.