基于VG-TSM模型的不同灌水模式下土壤镉迁移模拟及适用性研究  

Simulation and Applicability of Soil Cadmium Migration under Different Irrigation Modes Based on VG-TSM Model

作　　者：张启蒙 吴勇[1,2] 刘琴 张家文 卢铁文 ZHANG Qi-meng;WU Yong;LIU Qin;ZHANG Jia-wen;LU Tie-wen(College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059,Sichuan Province,China;State Key Laboratory for Geological Disaster Prevention and Geological Environment Protection,Chengdu 610059,Sichuan Province,China)

机构地区：[1]成都理工大学环境与土木工程学院,四川成都610059 [2]地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《中国农村水利水电》2023年第4期221-227,234,共8页China Rural Water and Hydropower

基　　金：四川省科技计划重点研发项目(2021YFS0294,2021YFN0128)。

摘　　要：为研究成都平原区典型水稻土中污染镉Cd在灌水时的迁移分布特征,探明VG-TSM(两点吸附)模型模拟的适用性。以动态土柱试验为基础,设计外源含Cd溶液注水+清水淋洗3种定额灌水模式以模拟不同污染情景下的Cd迁移特征,并利用Hydrus-1D软件中的VG-TSM模型对土柱试验结果进行拟合验证、预测分析与敏感性解析。结果表明:土壤中污染Cd的穿透能力受灌水模式影响,含Cd注水量越大时土壤的吸附缓冲作用越弱,峰值浓度越高;经均方根误差RMSE、相关系数R^(2)、平均绝对误差MAE拟合分析,发现模拟值与实测值较吻合,验证了Hydrus-1D-Cd溶液时空迁移模型的合理性;延长模拟时间发现,土壤中Cd的进一步解析释放特征符合以化学非平衡作用溶质的TSM模型解释;经参数敏感分析,VG模型控制下的水力特征参数θS、KS,TSM模型控制下的溶质运移参数ρ、Kd、f对模拟输出结果的影响较大;另外,土壤质地、土柱试验尺度、灌水模式等因素也可能影响参数敏感性而造成模型模拟结果的非理性波动。In order to study the migration and distribution characteristics of contaminated cadmium Cd in typical paddy soil in Chengdu Plain during irrigation,the applicability of VG-TSM(two-point adsorption)model is verified.Based on the dynamic soil column test,three irriga⁃tion modes of exogenous Cd solution water injection+clear water leaching quota are designed to simulate the Cd migration characteristics un⁃der different pollution scenarios,and the VG-TSM model in Hydrus-1D software is used for fitting verification,prediction analysis and sen⁃sitivity analysis of soil column test results.The results show that the penetration ability of Cd in soil is affected by irrigation mode.The greater the water injection amount of Cd,the weaker the adsorption buffer effect of soil,and the higher the peak concentration.Through the fitting analysis of root mean square error RMSE,correlation coefficient R^(2)and average absolute error MAE,it is found that the simulated value is in good agreement with the measured value,which proves the rationality of the spatio-temporal migration model of Hydrus-1D-Cd solution.Ex⁃tending the simulation time,it is found that the further analytical release characteristics of Cd in soil are consistent with the TSM model of chemical non-equilibrium solutes.Through parameter sensitivity analysis,the hydraulic characteristic parametersθs and Ks under the con⁃trol of VG model,and the solute transport parametersρ,Kd and f under the control of TSM model have a profound influence on the simulation output results.In addition,soil texture,soil column test scale,irrigation mode and other factors may also affect parameter sensitivity and cause irrational fluctuation of simulation results.

关 键 词：镉(CD) 灌水模式 VG-TSM模型 参数敏感性 

分 类 号：TV213[水利工程—水文学及水资源] S274.1[农业科学—农业水土工程]