Ms. Nahed Ben-Salem1, Mr. Alexander Wachholz1, Dr. Robert Reinecke2, Prof. Dr. Michael Rode1, Prof. Dr. Dietrich Borchardt1, Dr.
1. Department of Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environmental Researchâ€UFZ, Magdeburg
2. ederal Institute of Hydrology P.O. Box 200253, 56002 Koblenz
The Mediterranean region is susceptible to climate change impacts and anthropogenic pressures. It is also subject to frequent drought periods, especially with the high seasonality of precipitation and increased water demands. The effect of this critical situation is getting worse, particularly in coastal areas characterized by growing population density, socio-economic activities and intensive agriculture. In this circumstance, groundwater plays a crucial role in water security in the Mediterranean region. Groundwater is considered as a strategic freshwater reserve; however, its status remains poorly characterized and its total budget uncertain. In this talk we argue that large-scale groundwater modelling is crucial tool to confront the challenges of climate change impacts on groundwater availability and to implement science-based adaptation and mitigation measures in the Mediterranean.
In recent years, groundwater modelling has moved from local to regional/global scale, offering insights into the status of data-scarce regions. However, it remains unclear to what extent those models can be used to support management decisions. This study aims to evaluate the performance of three global gradient-based groundwater models to represent the steady-state of groundwater levels in the Mediterranean region. In this study, the groundwater models of Fan et al. (2013), de Graaf et al. (2017), and Reinecke et al. (2019) are used.
Steady-state results of the three models are compared to each other and to available in-situ data from different regional studies around the Mediterranean. Preliminary results showed that there is a big discrepancy between the three compared model outputs. More specifically, the de Graaf et al. (2017) model presents a deeper water table than Reinecke et al. (2019) and Fan et al. (2013), while de Graaf et al. (2017) generally shows a greater variability in simulated water table depth.
The aim of this study is to advance our understanding of large-scale groundwater modeling, which in turn can be an important tool for an improved groundwater resources management by using modelling as means for predicting the effect of climate change and anthropogenic pressures on groundwater levels in data-scarce regions.