基于Hydrus-3D模型的再生水涌泉根灌模拟及布置参数预测

为了探寻再生水果树涌泉根灌条件下灌水器的最优布设埋深和间距,以饱和―非饱和土壤水分运动理论为依据,选取了典型研究区一年和多年生桃树,利用Hydrus-3D模型对再生水涌泉根灌土壤水分入渗过程进行数值模拟,并将模拟结果与田间试验实测结果进行对比验证,同时预测了双源涌泉根灌灌水器的最优布置参数。结果表明,Hydrus-3D模型对再生水涌泉根灌湿润锋运移距离以及灌水结束后不同时刻含水量分布的模拟值和实测值之间决定系数R 2均大于临界决定系数,均方根误差RMSE分别小于1.5和0.05,且F检验P值均在0.05以上。说明Hydrus-3D模型可以用于再生水双源涌泉根灌土壤水分运移的模拟;利用Hydrus-3D模型预测结果表明,1,5,10年生桃树再生水双源涌泉根灌灌水器最优布设埋深分别为35,35,45 cm,最优布设间距分别为40,50,40 cm。

Simulation of Surge-root Irrigation with Reclaimed Water and Prediction of Emitters Layout Parameters Based on Hydrus-3D

Soil water infiltration movement is an important part of the evaluation of surge-root irrigation efficiency. Based on the theory of saturated-unsaturated soil water movement, we simulated the soil water infiltration under surge-root irrigation with a double-point source by Hydrus-3D and compared the simulated results with the field measured data. At the same time, the typical peach trees were selected and the optimal arrangement parameters of the surge-root irrigation were predicated. The study results showed that all the correlation coefficients between the simulated and the measured values of the soil wetting front of the surge-root irrigation and soil water content after irrigation were always greater than the critical correlation coefficient, RMSE was less than 1.5 and 0.05, respectively, and the P values of T-test were greater than 0.05. It indicated that Hydrus-3D could be used for soil moisture migration simulation of surge-root irrigation with reclaimed water. Using the Hydrus-3D model, the results showed that the optimal depth was 35, 35, and 45 cm respectively for peach tree with 1-year, 5-year and 10-year old, and the corresponding spacing was 40, 50, and 40 cm respectively.