Interplay of free convection and chemical reactions in groundwater below salt lakes

除了作为生物栖息地和气候变化指标的特殊价值外，盐湖对水资源管理也很重要，因为湖泊引起的盐碱化可能强烈影响其附近的地下水质量。由于密度驱动流和化学反应的耦合，盐湖与地下水之间的相互作用和质量传递是非常复杂的。特别是自由对流和化学反应之间的相互作用还没有得到很好的理解，迄今为止，只有少数的努力已经量化的化学反应和密度驱动的地下水流模式的反馈。本研究的总体目标是研究不同条件下密度驱动流与化学反应之间的反馈，并探讨不同时空尺度下异质性和气候或水文条件的作用。这将通过使用PHT3D的可变密度版本的数值研究来实现。模拟将从具有均匀和各向同性参数分布的一维概念设置开始，逐步增加复杂性，并将扩展到概念垂直二维场景。在对反馈机制有了更深入的了解后，将该模型应用于两个不同的现场，为验证模型结果提供了一个很好的数据库。

Besides their particular value as biological habitats and indicators for climatic changes, salt lakes are important for water resource management as lake induced salinisation may strongly affect the groundwater quality in their vicinity. Owing to density driven flow coupled with chemical reactions the interaction and mass transfer between salt lakes and groundwater is extremely complex. Especially the interplay between free convection and chemical reactions is not well understood, and to date only a few efforts have been made to quantify the feedback of chemical reactions and density driven groundwater flow patterns. The general objective of this study is to investigate the feedback between density driven flow and chemical reactions under different conditions and to explore the role of heterogeneity and climatic or hydrologic conditions at different tempo-spatial scales. This will be achieved by numerical studies using the variable density version of PHT3D. Simulations will start with one-dimensional conceptual settings with homogeneous and isotropic parameter distributions with stepwise increasing complexity and will be extended to conceptual vertical two-dimensional scenarios. After a refined understanding of the feedback mechanisms has been obained, the model will be applied to two different field sites which provide an excellent database for verifying the model results.