GroMoPo Metadata for Dalian City seawater intrusion model

Since 1980s, seawater intrusion in coastal aquifers caused by groundwater over-abstraction has led to extensive deterioration in groundwater quality and quantity and has been fazing local residents in Zhoushuizi district of the metropolitan Dalian City in northern China. In this study, a three-dimensional (3D) density-dependent numerical model was constructed to simulate the seawater intrusion process in heterogeneous coastal aquifers in Zhoushuizi district of the metropolitan Dalian City. Considering that the groundwater flow in karst aquifers in northern China is relatively uniform, approximately following Darcy's law, the fracture-karst aquifer in Zhoushuizi district of Dalian City was simplified as an equivalent porous medium. To further identify the hydrogeological parameters of the aquifers in the study area, the model was calibrated and validated using the observation heads and concentrations. Based on the current groundwater abstraction conditions of the study area, the calibrated and validated model was then applied to predict the dynamics and trend of seawater intrusion for the following 30 years from 2010 to 2040 under different rainfall scenarios. The overall extent of seawater intrusion in the future would be even more severe under different prediction scenarios. This 3D seawater intrusion model provides the theoretical basis for implementing a reasonable allocation of groundwater resource, which may significantly affect the sustainability of water resources.

自20世纪80年代起，中国北方大都市大连市周水子区内，因地下水过度开采引发的滨海含水层海水入侵问题已导致地下水水质与水量大幅恶化，且长期困扰当地居民。本研究针对大连市周水子区的非均质滨海含水层，构建了三维（3D）变密度数值模型以模拟海水入侵过程。考虑到中国北方喀斯特含水层内的地下水流相对均匀，近似遵循达西定律，研究将大连市周水子区的裂隙-喀斯特含水层简化为等效多孔介质。为进一步确定研究区含水层的水文地质参数，研究利用观测水头与浓度数据对该模型进行了校准与验证。基于研究区当前的地下水开采现状，经校准与验证后的模型被应用于2010年至2040年共30年的不同降雨情景下海水入侵的动态变化与发展趋势预测。不同预测情景下，未来海水入侵的整体范围将更为严峻。该三维海水入侵模型可为实现地下水资源的合理配置提供理论依据，这将对水资源可持续性产生显著影响。