Integration of 2D Lateral Groundwater Flow into the Variable Infiltration Capacity (VIC) Model and Effects on Simulated Fluxes for Different Grid Resolutions and Aquifer Diffusivities
Integration of 2D Lateral Groundwater Flow into the Variable Infiltration Capacity (VIC) Model and Effects on Simulated Fluxes for Different Grid Resolutions and Aquifer Diffusivities
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DOI：
10.3390/w13050663
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发表时间：
2021-02
期刊：
影响因子：
3.4
通讯作者：
J. Scheidegger;C. Jackson;S. Muddu;S. K. Tomer;R. Filgueira
中科院分区：
文献类型：
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作者：
J. Scheidegger;C. Jackson;S. Muddu;S. K. Tomer;R. Filgueira
需要将地下水过程的更好表述纳入大规模水文模型，以改进对区域乃至全球规模水文和气候的模拟，并更好地理解人类和自然系统之间的反馈。我们将一个二维地下水流模型的可变入渗能力（维克）水文模型代码，以解决其缺乏横向地下水流的组成部分。地下水位与含水层饱和的维克土柱耦合，允许含水层和土壤之间的双向水交换。然后，我们研究了含水层特性和网格分辨率的变化如何影响模拟的蒸散量（ET），径流和地下水补给。我们模拟了九个理想化的，均匀的含水层与不同的组合transmittance，存储系数，和三个网格分辨率。细胞ET，径流和补给的大小显着取决于地下水位深度。反过来，随着网格分辨率从1°增加到0.05°，对于中等和高transmittance系统，地下水位深度的分布变化很大，导致模型平均通量的变化高达平均降雨量的12.3%。对于低透水性含水层，由于地下水横向流量较低，增加网格分辨率的效果很小，维克网格单元表现为垂直柱。将二维地下水模型纳入维克国际中心，将使今后能够展示抽取地下水进行灌溉的情况，以及地下水利用与水文循环之间的反馈。
Better representations of groundwater processes need to be incorporated into large-scale hydrological models to improve simulations of regional- to global-scale hydrology and climate, as well as understanding of feedbacks between the human and natural systems. We incorporated a 2D groundwater flow model into the variable infiltration capacity (VIC) hydrological model code to address its lack of a lateral groundwater flow component. The water table was coupled with the variably saturated VIC soil column allowing bi-directional exchange of water between the aquifer and the soil. We then investigated how variations in aquifer properties and grid resolution affect modelled evapotranspiration (ET), runoff and groundwater recharge. We simulated nine idealised, homogenous aquifers with different combinations of transmissivity, storage coefficient, and three grid resolutions. The magnitude of cell ET, runoff, and recharge significantly depends on water table depth. In turn, the distribution of water table depths varied significantly as grid resolution increased from 1° to 0.05° for the medium and high transmissivity systems, resulting in changes of model-average fluxes of up to 12.3% of mean rainfall. For the low transmissivity aquifer, increasing the grid resolution has a minimal effect as lateral groundwater flow is low, and the VIC grid cells behave as vertical columns. The inclusion of the 2D groundwater model in VIC will enable the future representation of irrigation from groundwater pumping, and the feedbacks between groundwater use and the hydrological cycle.