基于改进的HYDRUS-2D模型暗管排水过程模拟  

Simulation of drainage process of subsurface pipe based on improved HYDRUS-2D model

作　　者：刘义 曾文治[1] 敖畅 雷国庆 伍靖伟[1] 黄介生[1] LIU Yi;ZENG Wenzhi;AO Chang;LEI Guoqing;WU Jingwei;HUANG Jiesheng(State Key Laboratory of Water Resource and Hydropower Engineering Science, Wuhan University, Wuhan, Hubei 430072, 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

出　　处：《干旱地区农业研究》2020年第4期221-228,共8页Agricultural Research in the Arid Areas

基　　金：国家自然科学基金重大项目“区域排盐工程模式优化与灌排协同调控”(51790533)。

摘　　要：为了提高HYDRUS-2D模型在暗管排水中的模拟精度,提出了虚拟土层(VSL)和实际开孔面积(AHA)两种方法来代替HYDRUS-2D在暗管排水中的暗管原有渗透边界(PSB)。研究表明:VSL和AHA模型的模拟值与实测值具有较好的一致性;土壤含盐量平方根误差(RMSE)分别为0.757、0.966 g·kg^-1,决定系数(R^2)分别为0.977和0.964;土壤含水率的RMSE分别为0.007、0.008 cm^3·cm^-3,R2分别为0.885和0.794。此外,VSL在模拟排水方面(RMSE=9.48L,R2=0.93)和模拟排盐方面(RMSE=0.225 kg,R^2=0.922)的模拟精度均高于AHA和PSB,可见,VSL更适用于暗管边界。进一步建立了VSL的环宽(RW)与其饱和导水率(Ks)之间的经验公式(R2=0.99,P<0.01),当模拟区域和暗管布局变化时,该经验公式可用于确定VSL的模型参数,其模拟结果可用于指导相关地区的暗管布局。In order to improve the simulation accuracy of HYDRUS-2D in subsurface pipe drainage,this paper proposed two strategies of virtual soil layer(VSL)and actual opening area(AHA)to replace the previous seepage boundary(PSB)of HYDRUS-2D model in subsurface pipe drainage.The results showed that the simulated values of the VSL and AHA models were in good agreement with the measured values:the square root error(RMSE)of the salinity was 0.757 g·kg^-1 and 0.966 g·kg^-1,respectively,and the determination coefficient(R^2)was 0.977 and 0.964,respectively.The RMSE of soil water content was 0.007 cm^3·cm^-3 and 0.008 cm^3·cm^-3 and the R2was 0.885 and 0.794,respectively.In addition,the simulation accuracy of VSL in terms of drainage process(RMSE=9.48 L,R^2=0.93)and salt discharge process(RMSE=0.225 kg,R2=0.922)were higher than that of AHA and PSB.It is obvious that VSL was more suitable for subsurface pipe boundary.At the same time,this paper further fitted the empirical formula between the ring width(RW)of VSL and its saturated hydraulic conductivity(Ks)(R2=0.99,P<0.01).The empirical formula could be used to determine the model parameters of VSL when the layout of simulated domain and subsurface pipe changes,and the simulation results could be used to guide the layout of subsurface pipe in relevant areas.

关 键 词：暗管边界 土壤盐渍化 土壤含盐量 排水 排盐 土壤含水率 HYDRUS-2D模型 

分 类 号：S276[农业科学—农业水土工程] S287[农业科学—农业工程]