Novel physical and numerical methods for simulating water and heat transfer in land surface models.

用于模拟地表模型中水和热传递的新颖物理和数值方法。

• 批准号: 2202955
• 金额: --
• 依托单位: University of Reading
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2202955
• 关键词: Novel; physical; numerical; methods; simulating

Improved land surface modelling for the terrestrial water cycle is critical for providing better forecasts within a changing climate, for example in flood prediction. Land surface models, such as UKMO's Joint UK Land Environment Simulator (JULES), describe unsaturated flow in soils through a numerical form of the Richards one-dimensional partial differential equation (PDE). Such a solution to a highly non-linear equation inevitably leads to numerical and accuracy issues, which impact on their hydrological performance. Recent attention has focussed on adopting novel approaches to hydrological models.This project concerns the implementation and testing of two recent 1-D unsaturated zone flow solution methods (Ogden et al., 2015; Lee, Baines and Langdon, 2015) into JULES. Both methods use a velocity-based PDE for the depth in terms of the water content, the Ogden approach through a hodograph transformation, the Baines approach through local mass conservation. The (different) PDEs are stepped forward in time using an explicit scheme.The Ogden Soil Moisture Velocity Equation (SMVE) method has already been applied to the transport of three regimes of soil moisture, namely infiltration, wetting fronts disconnected from the surface, and groundwater recharge. The Baines approach (CMF) awaits development.The student will extend both approaches to account for heat flow.The studentship affords the opportunity to apply computational modelling to a real problem of high importance, and will include visits to the UKMO.The intellectual challenge will be to derive a consistent method for coupling water and heat transport within the soil.

改进陆地水循环的地表模型对于在气候变化的情况下提供更好的预测至关重要，例如洪水预测。陆地表面模型，例如 UKMO 的联合英国土地环境模拟器 (JULES)，通过理查兹一维偏微分方程 (PDE) 的数值形式描述土壤中的不饱和流。这种高度非线性方程的解不可避免地会导致数值和精度问题，从而影响其水文性能。最近的注意力集中在采用新的水文模型方法上。该项目涉及在 JULES 中实施和测试两种最新的一维非饱和区域流求解方法（Ogden 等人，2015 年；Lee、Baines 和 Langdon，2015 年）。两种方法都使用基于速度的偏微分方程来计算含水量的深度，奥格登方法通过实线变换，贝恩斯方法通过局部质量守恒。使用显式方案及时推进（不同的）偏微分方程。奥格登土壤湿度速度方程（SMVE）方法已应用于三种土壤水分状态的传输，即渗透、与地表分离的湿润锋和地下水补给。贝恩斯方法 (CMF) 等待开发。学生将扩展这两种方法来解释热流。学生奖学金提供了将计算模型应用于高度重要的实际问题的机会，并将包括参观 UKMO。智力挑战将是导出一种一致的方法来耦合土壤内的水和热传输。