Evaluating a Coupled Phenology-Surface Energy Balance Model to Understand Stream-Subsurface Temperature Dynamics in a Mixed-Use Farmland Catchment
Evaluating a Coupled Phenology-Surface Energy Balance Model to Understand Stream-Subsurface Temperature Dynamics in a Mixed-Use Farmland Catchment
复制标题
评估物候-地表能量平衡耦合模型以了解混合用途农田流域中的溪流-地下温度动态
DOI：
10.1029/2018wr023644
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发表时间：
2019
影响因子：
5.4
通讯作者：
Qiu H
中科院分区：
文献类型：
--
作者：
Qiu H
河流温度是控制水生态系统物理和生态地球化学过程的关键变量。地表和次表层过程之间复杂的物理相互作用使得流域尺度上的流温动态的精确模拟成为一项具有挑战性的任务。在这项研究中，我们提出了一个综合的，流域尺度的框架来模拟流，土壤，河床，和地下水温度的水文和植被动态的影响下，在英格兰中部的混合土地利用流域。耦合模式中的物候和地表能量模块用于量化植被过程对辐射通量的影响（例如，冠层遮光和植被生长对光学参数的影响）。该模型能够准确地模拟不同水文域的水热通量的运动和分配，观测和模拟温度的R2值在0.60-0.87之间。模拟地下水位和流阶段允许识别的获得和失去的部分流达到和达西通量的估计。模拟结果表明，在0.3 m以下的增益河段，显著抑制昼夜河床温度波动，而在损失河段，昼夜波动表现出相对较强的波动低于0.3 m。该模型能够评估不同过程对流热预算的相对贡献。结果表明，净辐射是主要的热源，而潜热通量是主要的热汇。该模型提供了一个有用的工具，明确模拟水和热通量以及温度依赖的反应速率在地球化学分析。
Stream temperature is a key variable that controls both physical and biogeochemical processes in aquatic ecosystems. Complex physical interactions between land surface and subsurface processes make accurate simulations of stream temperature dynamics at catchment scales a challenging task. In this study we propose an integrated, catchment‐scale framework to model stream, soil, streambed, and groundwater temperatures under the influence of hydrologic and vegetation dynamics in a mixed land use catchment in central England. The phenology and surface energy modules in the coupled model were used to quantify the impacts of vegetation processes on radiation fluxes (e.g., canopy shading and the effect of vegetation growth on optical parameters). The model enabled accurate simulations of the movement and partitioning of water and thermal fluxes in different hydrologic domains withR2values of observed and simulated temperatures in the range 0.60–0.87. Simulated groundwater heads and stream stages allowed the identification of gaining and losing portions of stream reaches and the estimation of Darcy fluxes. Simulation results show significantly dampened diel streambed temperature fluctuations below 0.3 m in gaining reaches, while in losing reaches the diel fluctuations showed relatively strong fluctuations below 0.3 m. The model enabled evaluation of the relative contributions of different processes to the stream thermal budget. Results indicate that net radiation was the dominant heat source, while latent heat flux was the primary heat sink. The model provides a useful tool to explicitly simulate water and heat fluxes as well as temperature‐dependent reaction rates in biogeochemical analyses.