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Process-based modeling of soil hydrology and its verification at the Biosphere 2 Landscape Evolution Observatory

基于过程的土壤水文建模及其在生物圈2号景观演化观测站的验证

基本信息

批准号：
418089968
负责人：
Dr. Hannes Bauser
金额：
--
依托单位：
Department of Hydrology and Atmospheric Sciences
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/418089968?language=en
关键词：
Process based modeling soil hydrology

项目摘要

Soil water movement is a key process in several provisioning and regulating ecosystem services. However, it’s accurate prediction through mathematical models remains a challenge, because of large uncertainties in all model components, even when using process-based descriptions like the Richards equation.Data assimilation methods offer the possibility to combine information from uncertain models and uncertain measurements into an improved consistent description of the state, provided the uncertainties can be quantified correctly. The largest uncertainties are typically associated with the hydraulic properties of the soil. Including the pertinent hydraulic parameters into an augmented state allows data assimilation methods to estimate them. This can even be achieved in the presence of model errors like preferential flow, if these errors are considered appropriately. So far, such consistent descriptions have only been demonstrated on smaller scales up to one-dimensional soil profiles. On larger scales detailed process-based descriptions have not yet been accomplished. This is due to lack of information on the heterogeneous soil hydraulic properties in combination with the highly nonlinear and interacting processes.A unique research infrastructure for the experimental study of soil hydrology on hillslopes is the Landscape Evolution Observatory (LEO) at Biosphere 2. It consists of three artificial hillslopes with an extensive sensor and sampler network.To improve our understanding at this larger hillslope scale, the objective of this project is the consistent and process-based description of soil water movement at LEO including the representation of heterogeneity and evolution of soil hydraulic parameters. This will be addressed along the following lines: (i) deduce the evolution of soil hydraulic parameters in time through data assimilation at selected profiles in the hillslopes, (ii) determine the heterogeneity of soil hydraulic properties and their effects through hydraulic experiments and forward simulations, and (iii) gain and verify a consistent description of parts of the hillslope through data assimilation methods. This project will answer if current monitoring techniques suffice to obtain a consistent and usefully accurate representation of hillslope hydrology and if so, how the description is achieved and with what uncertainty. Beyond this, I expect quantitative insight into the formation of heterogeneity at LEO.

土壤水分运动是提供和调节生态系统服务的关键过程。然而，通过数学模型进行准确预测仍然是一个挑战，因为所有模型组件中都存在很大的不确定性，即使在使用基于过程的描述(如Richards方程)时也是如此。数据同化方法提供了将来自不确定模型和不确定测量的信息组合到对状态的改进一致描述中的可能性，前提是不确定性可以正确量化。最大的不确定性通常与土壤的水力特性有关。将相关水力参数纳入增强状态允许数据同化方法估计它们。如果适当地考虑这些误差，甚至可以在存在优先流等模型误差的情况下实现这一点。到目前为止，这种一致的描述只在较小的尺度上被证明，甚至一维土壤剖面。在更大范围内，尚未完成基于流程的详细描述。生物圈2号的景观演变观测站(LEO)是一个独特的研究基础设施，它由三个人工坡地组成，带有广泛的传感器和采样器网络。为了提高我们对更大的坡面尺度的理解，本项目的目标是一致的和基于过程的描述LEO的土壤水分运动，包括土壤水力参数的非均质性和演化的表示。这将沿着以下路线进行：(I)通过在选定的坡面上的数据同化来推断土壤水力参数随时间的演变，(Ii)通过水力试验和正演模拟来确定土壤水力特性的异质性及其影响，以及(Iii)通过数据同化方法获得并验证对部分坡面的一致描述。该项目将回答目前的监测技术是否足以获得一致和有用的准确的山坡水文表示，如果是，如何实现描述，以及具有什么不确定性。除此之外，我期待着对狮子座异质性形成的定量洞察。