Groundwater budgets and fluxes are affected by human activities and climate change. Numerical models are cost-effective tools to investigate the different components of the hydrologic cycle. In this study, a groundwater flow model of the unconfined aquifers of the Campania region (Italy) has been developed and calibrated in Processing Modflow 11, resulting in an accurate assessment of groundwater fluxes and their trends over fifteen years (2000–2015). The model was implemented using a high-resolution grid to capture small hydrogeological features such as wells and rivers and informed by time variable datasets used as boundary conditions (i.e., river and sea levels, aquifer recharge, evapotranspiration, and discharge from adjacent systems). Good calibration and validation performances were achieved for piezometric heads (R² = 0.958). A set of scenarios was developed using constant boundary conditions (i.e., constant sea-level BC, uniform extinction depth BC), and the outputs were compared, quantitively assessing differences in groundwater fluxes. Simulations pointed out that using time series to inform boundary conditions in the model does not always result in a significant change in the computed fluxes. Overall, non-uniform extinction depth was the most influential condition, while both rivers and sea level conditions barely affected groundwater budgets. In addition, results highlighted the need for an accurate estimation of spatiotemporal variations of both recharge and evapotranspiration, due to their strong seasonal variability and their massive contribution to the hydrogeological cycle. Finally, a marked increase of evapotranspiration fluxes controlled by interannual variability of precipitation and atmospheric temperatures has been quantified over the modelled period.

中文翻译：

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坎帕尼亚地区（意大利）边界条件动态对地下水收支的影响

地下水收支和通量受人类活动和气候变化的影响。数值模型是研究水文循环不同组成部分的经济有效的工具。在这项研究中，坎帕尼亚地区（意大利）非承压含水层的地下水流模型已经在 Processing Modflow 11 中开发和校准，从而准确评估了十五年（2000-2015 年）的地下水通量及其趋势。该模型使用高分辨率网格来实现，以捕捉井和河流等小型水文地质特征，并通过用作边界条件的时间变量数据集（即河流和海平面、含水层补给、蒸发蒸腾和相邻系统的排放）提供信息。测压头（R²= 0.958）。使用恒定边界条件（即恒定海平面 BC、均匀消光深度 BC）开发了一组情景，并对输出进行了比较，定量评估了地下水通量的差异。模拟指出，使用时间序列来告知模型中的边界条件并不总是会导致计算出的通量发生显着变化。总体而言，不均匀的灭绝深度是最有影响的条件，而河流和海平面条件几乎不影响地下水预算。此外，结果强调需要准确估计补给和蒸发量的时空变化，因为它们具有很强的季节性变化和它们对水文地质循环的巨大贡献。最后，