New consistent models for an effective description of root water uptake

准确了解土壤-植物-大气系统中的水分运移对于生态和农业科学中的许多领域都具有重要意义。水的输运与溶质和能量输运现象是耦合的。因此，水传输中的错误预测导致对系统组件中水、溶质和能量的命运的错误预测。很大一部分土壤水分通过植物输送到大气中。因此，一个合理的描述根系水分吸收是至关重要的。通常，假设有代表性的基本体积(REV)，这样的传输过程被有效地描述。这一建议表明，在REV尺度上有效描述根系吸水的典型模型在物理上是不一致的。提出了改进建议，一方面导致物理上的一致性，另一方面又使其具有实用性。在这里，实用性意味着模型参数化所需的信息很小，并且模型可以相对容易地实施到现有的模拟软件中。这将在项目中进行，以便在不同边界条件下的敏感性研究中对新旧模型进行分析，并针对具有均匀和非均匀分布的土壤性质的不同土壤类型进行分析。最后，用文献数据对新模型进行检验。

A precise knowledge of water transport in the soil-plant-atmosphere system is significant for many fields in ecological and agricultural sciences. The water transport is coupled with solute as well as to energy transport phenomena. Thus, erroneous predictions in water transport lead to erroneous predictions of the fate of water, solutes and energy in the system components. A large portion of the soil water is transported via plants to the atmosphere. Therefore, a sound description of root water uptake is of crucial importance. Usually, such transport processes are described effectively, assuming a representative elementary volume (REV). This proposal shows that the typical models for an effective description of root water uptake on the REV-scale are physically inconsistent. Improvements are suggested which lead to physical consistency on the one hand and to practicability on the other hand. Practicability means here that the required information for parameterization of the models is small and that the models can be relatively easily implemented into existing simulation software. This shall be done in the project in order to analyze the new and the old models in a sensitivity study under different boundary conditions and for different soil types with homogeneous and heterogeneous distribution of the soil properties. In the last step the new models shall be tested with literature data.