An inexorable depletion of groundwater occurs where groundwater abstraction exceeds the natural recharge, a typical state of (semi-)arid regions, which calls for sustainable management of groundwater resources. This study aims to assess the available storage and recharge rates on a national scale in time and space by modelling the natural recharge in combination with a method to evaluate changing groundwater volumes, which revealed measures to quantify the overdraft of the observed national groundwater resources in Jordan. Applying the combination of hydrological model and method to evaluate changing groundwater volumes, a climate-driven systematic decline of groundwater recharge was eliminated as responsible process, while overdraft leads to dropping groundwater tables. The major findings are, the intensity of groundwater abstraction from a basin becomes visible through the fact, that simulated baseflow exceeds significantly the observed baseflow. About 75% of Jordan's groundwater basins are subject to intense groundwater depletion, reaching annual rates of up to 1 m in some basins. The most affected areas are the basins Zarka, Azraq and the predominantly fossil groundwater reservoirs in Southern Jordan. Contrasting the past, when variable annual precipitation patterns did not negatively influence groundwater recharge, simulations show significantly reduced annual groundwater recharge all over Jordan. Particularly affected is the agricultural backbone in the Jordan Mountains, where recharge rates are predicted to vary between -30 mm/yr and +10 mm/yr in the coming decades, being reflected in the disappearance of freshwater springs and ascending saltwater. The applied methodology is relevant and transferable to other data- and water scarce areas worldwide, allowing (i) a fast estimation of groundwater reservoir development on a national scale and (ii) an investigation of long-term effects of overdraft.

中文翻译：

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在全国范围内计算压力多含水层资源的人为消耗。

当地下水的抽取量超过自然补给量时（在（半）干旱地区的一种典型状态），地下水将不可避免地耗竭，这需要对地下水资源进行可持续管理。这项研究旨在通过对自然补给进行建模并结合评估地下水量变化的方法来评估全国时空规模上的可用存储和补给率，该方法揭示了量化约旦观测到的全国地下水资源透支的措施。应用水文模型和方法相结合的方法来评估地下水量的变化，消除了由气候驱动的地下水补给量的系统下降，这是负责任的过程，而透支则导致地下水位下降。主要发现是 通过模拟底流明显超过观测到的底流这一事实，可以看出从盆地抽取地下水的强度。约旦的地下水流域中约有75％的地下水被严重耗竭，某些流域的年流率高达1 m。受灾最严重的地区是扎尔卡盆地，阿兹拉克盆地以及约旦南部主要的化石地下水库。与过去相反，当可变的年降水量模式不会对地下水补给产生负面影响时，模拟表明，整个约旦的年度地下水补给量明显减少。受其影响特别严重的是约旦山脉的农业骨干，预计未来几十年的补给率将在-30毫米/年至+10毫米/年之间变化，反映在淡水泉水消失和盐水上升中。所采用的方法是相关的，并且可以转移到全球其他数据和缺水地区，从而可以（i）在全国范围内快速估算地下水库的开发，以及（ii）研究透支的长期影响。