Soil moisture patterns: linking hydrological processes at the event and inter-event time scales

土壤湿度模式：将事件和事件间时间尺度的水文过程联系起来

• 批准号: 342447-2007
• 负责人: TrompvanMeerveld, Ilja
• 金额: $ 1.46万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=458800
• 关键词: Soil; moisture; patterns; linking; hydrological; Soil; moisture; patterns; linking; hydrological

Soil-Vegetation-Atmosphere-Transfer (SVAT) models and climate models need to better predict the effects of climate change or land use change. To do so they must describe the lateral moisture fluxes and account for the spatial variability in soil moisture more realistically than at present because heterogeneity in plant available water can have a strong impact on the surface energy and water budgets. The objective of the proposed research is to obtain a systematic understanding of the 3D soil moisture dynamics and the environmental or site conditions controlling the development of spatial soil moisture patterns and spatial variability in lateral flow. Field experiments focusing on both the event and the inter-event time scales will be combined with modeling experiments. The field experiments will be conducted in the Malcolm Knapp Research Forest. The field measurements will follow a nested approach in order to include all landscape units and to be able to explore scale effects. Soil moisture will be measured manually throughout the soil profile at many locations and continuously at several locations. To determine the feedbacks between soil moisture and transpiration, sapflow will be measured with constant heat sapflow sensors. The 3D soil moisture patterns will be related to lateral flow patterns during precipitation events as the internal water table dynamics will be characterized as well. Tracer experiments in the wet and the dry season will support the determination of the spatial variability and occurrence of lateral subsurface flow. The data from these field experiments will be used to develop and validate a distributed water balance model, which will be used in a virtual experiment and scenario testing mode. The model will be used to determine under which environmental conditions specific soil moisture patterns form. In the future this new information will be incorporated in a decision tree approach to determine what type of spatial variability in soil moisture is likely to occur in an area and what would be an appropriate representation of the lateral water fluxes. This will lead to more site specific representations of lateral hydrological processes in SVAT models and better predictions of the effects of land use or climate change.

土壤蔬菜 - 大气转移（SVAT）模型和气候模型需要更好地预测气候变化或土地利用变化的影响。为此，他们必须描述侧向水分通量，并比目前更现实地解释土壤水分的空间变异性，因为植物可用水的异质性可以对表面能量和水预算产生强大的影响。拟议研究的目的是系统地了解3D土壤水分动力学以及控制空间土壤水分模式发展和横向流动空间变异性的环境或现场条件。关注事件和事件间时间尺度的现场实验将与建模实验相结合。现场实验将在Malcolm Knapp研究森林中进行。现场测量将遵循嵌套方法，以包括所有景观单元并能够探索规模效应。土壤水分将在许多位置的土壤剖面中手动测量，并在多个位置连续测量。为了确定土壤水分和蒸腾之间的反馈，将使用恒定的热sapflow传感器来测量SAPFLOW。 3D土壤水分模式将与降水事件期间的横向流动模式有关，因为内部水桌动力学也将被表征。在湿季节和旱季中进行的示踪剂实验将支持确定空间变异性和横向表面流的发生。这些现场实验的数据将用于开发和验证分布式水平衡模型，该模型将用于虚拟实验和场景测试模式。该模型将用于确定在哪些环境条件下形成了特定的土壤水分模式。将来，这种新信息将纳入决策树方法中，以确定土壤水分中可能发生哪种空间变异性，以及什么是侧向水通量的适当表示。这将导致SVAT模型中横向水文过程的更多特定地点表示，并更好地预测土地使用或气候变化的影响。