How Complex Groundwater Flow Systems Respond to Climate Change Induced Recharge Reduction?

Abstract

Our recent knowledge about the role of different fluid driving forces in the response of groundwater flow systems to climate change is still limited. This current study aimed to evaluate possible spatial and temporal changes in complex, gravity- and overpressure-driven groundwater flow systems induced by climate change and look for general trends and characteristics of the flow field using 2D transient groundwater flow simulations. Results showed significant large-scale changes in the transient subsurface flow field and flow dynamics due to recharge reduction. Local gravity-driven flow systems are the most vulnerable to atmospheric processes, while overpressured regimes are expected to be independent of direct climatic variability. By the involvement of different degrees of overpressure, it was revealed that, as the degree of overpressure increases, the penetration depth of the topography-driven local flow systems decreases. The higher the overpressure, the lower the climate change-induced groundwater level decrease over time, suggesting the buffering effect of overpressure as a fluid driving force in the flow systems’ response to the changes in hydrologic parameters. The main novelty of the study is the involvement of different fluid driving forces in the evaluation with the combination of a regional scale investigation, which is unique in the context of climate change effects on groundwater systems.