National Key R&D Project（No. 2016YFC0400204）and National Natural Science Foundation of China（No. 41771316）
黄土疏松多孔，气相占比较高，但是土壤干空气过程如何影响黄土水热运移尚不清楚。采用考虑土壤水-汽-热-气耦合的STEMMUS（Simultaneous Transfer of Energy，Mass and Momentum in Unsaturated Soil）模型，以黄土丘陵区苹果园为例，探讨土壤干空气对黄土土壤水热运移的影响。结果表明：（1）该模型可以较好地模拟果园土壤水热动态过程。通过优化土壤水力参数，STEMMUS模型在率定期与验证期模拟土壤水分的归一化均方根误差介于4.7%～30.0%，一致性指数介于0.83～0.96，模拟土壤温度的归一化均方根误差介于0.1%～9.9%，一致性指数介于0.76～0.99。（2）STEMMUS模型中考虑干空气机制的二相耦合模型模拟值较未考虑干空气机制的单相模型与实测值更为接近。降雨1d过后，耦合模型剖面土壤含水率增量明显小于单相模型，耦合模型的归一化均方根误差为0.07%，一致性指数介于0.93～0.97，单相模型的归一化均方根误差介于0.06%～0.2%，一致性指数介于0.95～0.96，鉴于该地区有压入渗等现象，耦合模型能更好反映实际土壤水分的运移过程。
[Objective] Loess is loose and porous, and hence contains much air. Soil water vapor movement in the soil is a complex process, in which water and air, two phases of fluids, drives and affects each other in vertical movement in the soil. So it is essential to get to know how dry air flow affects soil water and heat transfer to agricultural production in the Loess Plateau.[Method] To explore effect of soil dry air on soil moisture and heat transfer in an apple orchard of loess on a hill, the STEMMUS model (Simultaneous Transfer of Energy, Mass and Momentum in Unsaturated Soil)was adopted to simulate soil hydrothermal dynamic process. Numerical simulation is a feasible and economical method to reproduce the process.[Result] Results show:(1) the model is a useful tool to well simulate the dynamic process of soil water and heat in the soil. By optimizing the soil hydraulic parameters, in simulation of soil moisture druing the calibration and verification periods, the model varied in the range of 4.7%-30.0% in normalized root mean square error and in the range of 0.83-0.96 in consistency index, while in simulation of soil temperature, it did in the range of 0.1%-9.9% in normalized root mean square and in the range of 0.76-0.99 in consistency index; (2) the simulation using the two-phase coupling STEMMUS model with the dry air mechanism taken into account was more approximate to the measured value than the single-phase STEMMUS model without taking the dry air mechanism into account. After 1 day of rainfall, the increment of soil moisture content in the soil profile of the coupled model was obviously lower than that in the soil profile of the single-phase model. The coupled model was 0.07% in normalized root mean square error, and from 0.93 to 0.97 in consistency index, while the single phase model varied in the range of 0.06%-0.2% normalized root mean square error, and in the range of 0.95-0.96 in consistency index. Considering the existence of pressure infiltration in this area, the coupled model can better reflect the actual soil water movement.[Conclusion] Compared with traditional models, the STEMMUS model can better reflect the actual soil water and heat dynamics in loess by taking soil dry air mechanism into account, which is favorable to designing optimal management strategies for orchards on the Loess Plateau.
杨博,赵西宁,高晓东,潘岱立,霍高鹏,叶苗泰.耦合干空气机制的黄土水热运移过程模拟——以山地苹果园为例[J].土壤学报,2021,58(2):401-411. DOI:10.11766/trxb201910290395 YANG Bo, ZHAO Xining, GAO Xiaodong, PAN Daili, HUO Gaopeng, YE Miaotai. Simulation of Water and Heat Process in Loess by Incorporating Dry Air-flow Mechanism-A Case Study of an Apple Orchard on Mountain[J]. Acta Pedologica Sinica,2021,58(2):401-411.复制