用MODFLOW 6精确模拟通过浸泡水层的流量,使用增强的细胞连接
Alden M Provost, Kerry Bardot1, Christian D Langevin2
1School of Earth Sciences, University of Western Australia, Perth, Australia.
Ground water
|January 17, 2025
概括
在MODFLOW 6中的XT3D配方改善了浸泡水层中的地下水流模拟. 准确的结果需要足够的细胞连接,通过非结构化的网格和多个垂直层实现.
科学领域:
- 水文地质学 水文地质学
- 计算建模计算建模
- 地质科学 地质科学
背景情况:
- 在浸泡含水层中模拟地下水流动通常涉及模型细胞的变形,导致同一层内的相邻细胞之间的垂直偏移.
- 在MODFLOW中标准的两点流量配方并不准确地考虑这些垂直偏移.
- 在MODFLOW 6中XT3D多点流量配方是为了解决像垂直偏移这样的网格不规则而开发的.
研究的目的:
- 为了研究MODFLOW 6中XT3D配方的准确性,以模拟在的潜水层中具有显著的垂直偏移的地下水流.
- 为了确定在此类场景中使用XT3D的先前研究中观察到的不准确性的原因.
- 为了展示如何使用XT3D在具有挑战性的含水层几何结构下实现准确的模拟.
主要方法:
- 在MODFLOW 6.中评估基于标准导电量和XT3D多点流的标准流量配方.
- 使用一个合成基准模型的急剧下沉的含水层与不同的垂直偏移.
- 使用MODFLOW的非结构化网格类型和可变的垂直离散化 (模型层数量) 实现XT3D.
主要成果:
- 与标准配方相比,XT3D总体上提高了模拟准确性.
- 两种配方都没有提供准确的流量,当大型垂直偏移与标准离散存在时.
- 在使用非结构化网格和至少两个垂直模型层时,XT3D实现了预期的准确性,这表明足够的细胞连接是至关重要的.
结论:
- 之前的基准研究中XT3D的局限性是由于常见的MODFLOW 6离散包中的细胞连接性不足,而不是配方本身.
- 通过非结构化网格和垂直分离来促进充足的细胞连接,对于在复杂的浸泡含水层中使用XT3D精确地进行地下水流动模拟至关重要.
- 这些发现凸显了电网设计和离散选择对于可靠的水文地质系统数值建模的重要性.
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