土壤水热与根系吸水模型研究进展及其在西藏研究展望

在土壤根区水分运动规律的研究中,通常以土壤水热耦合模型来定量描述和预测土壤水分变化规律,以根系吸水模型来模拟作物根区根系吸水机理及过程。西藏高寒地区低压低氧、强辐射、近地层冷热交换频繁,加之土层稀薄,浅层土壤水转化过程复杂,作物生长受水热胁迫影响较为明显,作物根区的水热耦合作用对根系吸水及能量传输和物质运移影响显著。为了进一步探求西藏地区特殊水热条件下的根区水热运移机理,摸清西藏高寒区作物根系吸水规律,就国内外土壤水热耦合模型和根系吸水模型的相关研究做了综述,针对西藏地区特有的水热条件,建议将水热耦合模型与根系吸水模型结合应用,构建考虑水热耦合因素的根系吸水模型,以更好地适应当地实际,揭示根系土壤水分运动规律。

Research progress on models of soil water and heat and root water uptake and prospect in Tibet

In the study of water transport in root zone, the coupled model of soil water and heat is usually used to describe and predict soil water transport quantitatively, and the root water uptake model is used to simulate the process of root water uptake. With low pressure, low oxygen, strong radiation, and frequent exchange of cold and heat in the surface layers and thin soil layers, soil water transport in surface soil is complex and crop growing is affected by water and heat greatly. The root water uptake, energy transfer and substance migration are affected by hydro-thermal combination remarkably. In order to further explore the principle of hydro-thermal migration in the root zone and understand the characteristics of root water uptake in Tibet, the studies about model coupling soil water and heat and model of root water uptake in China and abroad are reviewed. In view of the unique hydrothermal conditions in Tibet, it is suggested to combine the coupled model of soil water and heat with the root water uptake model to build a root water absorption model considering the hydro-thermal coupling factors, so as to better adapt to the local reality and reveal the root soil water movement law.