GroMoPo Metadata for Columbia Aquifer model

A two-dimensional, field scale, finite-element ground water model was developed to simulate the ground water discharge process within an unconfined coastal aquifer, Model development was based on the density dependent fluid flow approach with water table and dynamic tidal boundary conditions, The performance of the model was compared against data collected from the Columbia Aquifer on the eastern shore of Virginia. The dynamic tidal boundary conditions were necessary to reproduce the surficial mixing zone observed within the ground water intertidal zone of the aquifer, The model was able to reproduce field data on the movement of the near-shore water table, ground water salt concentrations, and ground water discharge rates and patterns. The model was not able to replicate the short-term fluctuation in salt concentration observed within the surficial mixing zone, The inability to account for the wave action of the tides,within the intertidal zone is believed to be responsible for this difficulty. The development of the model provided a new method to investigate ground water discharge to coastal systems.

本研究构建了一款二维、野外尺度的有限元地下水模型，用于模拟非承压海岸含水层内的地下水排泄过程。模型开发基于密度依赖型渗流理论，并设置了潜水面与动态潮汐边界条件。将该模型的模拟结果与弗吉尼亚州东海岸哥伦比亚含水层的野外实测数据进行了对比验证。动态潮汐边界条件对于复现含水层地下水潮间带内观测到的表层混合带至关重要。该模型能够准确复现近岸潜水面变化、地下水盐度、地下水排泄速率与模式的野外实测数据，但无法复现表层混合带内观测到的盐度短期波动现象。研究认为，这一局限源于模型未考虑潮间带内潮汐的波浪作用。本模型的构建为海岸系统地下水排泄的相关研究提供了全新的技术手段。