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在根系分布试验观测的基础上,提出了三倍体毛白杨一维根系吸水模型,在考虑根系吸水情况下利用HYDRUS模型模拟了地下滴灌条件下三倍体毛白杨根区的土壤水分动态,通过田间试验对模型进行验证,并利用HYDRUS研究了不同灌水技术参数对土壤湿润模式的影响.结果表明:在灌溉结束和水分再分布24h后,土壤含水量模拟结果的相对平均绝对误差(RMAE)分别为7.8%和6.0%,均方根误差(RMSE)分别为0.036和0.026cm3.cm-3,说明HYDRUS模型能很好地模拟地下滴灌条件下三倍体毛白杨根区的短期土壤水分动态,且所建根系吸水模型合理;与2、4L.h-1的滴头流速和连续性灌溉相比,流速1L.h-1和脉冲式灌溉(每隔30min灌水30min)能增大土壤湿润体体积,且可以减少水分深层渗漏量,因此,对试验地三倍体毛白杨根区进行地下滴灌应首选流速1L.h-1的脉冲式灌溉.
Based on the observations of root distribution test, a one-dimensional water absorption model of Triploid Populus tomentosa was proposed. Under the condition of root water absorption, the model of HYDRUS was used to simulate the soil moisture dynamics of Triploid Populus tomentosa root under the condition of subsurface drip irrigation. The model was validated and the effects of different irrigation techniques on soil moisture model were studied by HYDRUS.The results showed that the relative mean absolute error (RMAE) of simulation results of soil moisture at the end of irrigation and water redistribution was 7.8 % And 6.0% respectively. The root mean square error (RMSE) was 0.036 and 0.026 cm3.cm-3, respectively, indicating that the HYDRUS model can simulate the short-term soil moisture dynamics under the condition of underground drip irrigation. Root water absorption model was reasonable. Compared with 2,4L-1 drip rate and continuous irrigation, the flow rate of 1L.h-1 and pulse irrigation (30min irrigation at 30min) Can reduce the amount of deep water leakage, therefore, the experimental triploid populus tomentosa root drip irrigation should be the preferred flow rate 1L.h-1 pulse irrigation.