Simulation of soil water dynamic of arid region jujube root zone under drip irrigation | 滴灌条件下干旱区枣树根区的土壤水分动态模拟

Chinese. 探明干旱区滴灌条件下枣树根区土壤水分的动态变化规律。以根系分布和土壤水分动态资料为基础，用考虑二维根系吸水的HYDRUS模型对滴灌条件下枣树根区土壤水分动态进行模拟，用含水率的模拟值与实测值的均方根误差(RMSE)和相对均方误差(RMAE) 检验模拟效果。（1）各层土壤水分90 d内的动态模拟结果显示，RMSE小于0.024 cm3/cm3，RMAE小于14.2%；（2）典型灌溉周期剖面含水率分布的模拟结果显示，RMSE小于0.016 cm3/cm3，RMAE小于5.6%。模拟结果表明，试验灌溉定额(450 m3/hm2)合理，灌溉周期需调整，说明该模型可以准确反映干旱区滴灌枣树土壤水分的动态分布，可为灌溉制度的制定提供理论依据。

English. The study explores the soil water dynamic rules in jujube root zone under drip irrigation in the arid area. Based on data of jujube roots density and soil water content, HYDRUS model is chosen to simulate the soil water dynamics in the root zone considering the two-dimensional root water uptake. The goodness of fit between simulation and measurement is measured by using root-mean-square-error (RMSE) and root-mean-absolute-error (RMAE) for the simulation with measured volumetric soil water contents. The results show that the RMSE values for simulating the 90 day’s soil water dynamics at the section of soil layers apiece below drip tube are less than 0.024 cm3/cm3, and the RMAE values are less than 14.2% as well. The RMSE values for simulating the distribution of soil moisture content in the section of root zone during the typical irrigation cycle are less than 0.016 cm3/cm3, and RMAE values are less than 5.6%. The simulation of the soil water dynamics indicates that the irrigation ration of experimental is scientific, however the irrigation cycle should be adjusted. It proves that the model performs well in simulating soil water dynamic in jujube root zone under drip irrigation.