The North Western Sahara Aquifer System (NWSAS) is characterized by unsustainable groundwater exploitation whose magnitude depends on the still unclear recharge value. It is extending over Libya, Tunisia, and Algeria, with an area of 10⁶ km². Here, we proposed an integrated approach combining Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) data to reconstruct groundwater storage variations (ΔGWS) between April 2002 and July 2016. ΔGWS values are then introduced in a regional water budget equation accounting for the temporal evolution of withdrawals and natural discharge to calculate the time variations of the recharge. Yearly reconstruction of the recharge shows a large variability with alternation of net positive recharge and periods of net diffuse discharge associated with evaporation. The temporal average effective recharge value for the period of interest is 1.76 ± 0.44 mm yr⁻¹. Lag-times for the recharge to reach the water table of 45 and 100 yrs characteristic of a diffuse recharge and corresponding vadose thickness in the range 3.90 ± 3.60 and 8.60 ± 8.10 m were identified using a cross-correlation analysis between reconstructed annual recharge and annual rainfall (AR). Statistical interpretation of the relation between ΔGWS, AR, and withdrawals shows that the anthropogenic effect (groundwater extraction) is the main controlling factor (99% of explained variance) in comparison to AR variations for the ΔGWS time series under consideration. A relation between long-term recharge and average annual rainfall (AAR) suggests a recharge representing 1.8 ± 0.3% of AAR in transboundary aquifers of the Saharan belt.

西北撒哈拉含水层系统（NWSAS）的特点是地下水开采不可持续，其开采量取决于仍不清楚的补给价值。它延伸到利比亚，突尼斯和阿尔及利亚，面积为10 ⁶  km ² 。在这里，我们提出了一个综合的方法重力恢复和气候实验（GRACE）和全球陆面数据同化系统（GLDAS）数据来重建地下水蓄水量变化（合并ΔGWS 2002年4月和2016年七月间）ΔGWS然后将这些值引入区域水预算方程中，以说明取水量和自然流量的时间变化，以计算补给量的时间变化。每年的补给重建显示出较大的可变性，即净正补给和与蒸发相关的净弥散放出的时间交替。感兴趣时段的时间平均有效充电值为1.76±0.44 mm yr ^-1。使用重建的年度补给量与年度补给量之间的互相关分析，确定补给到达45和100年地下水位的滞后时间（弥散补给的特征以及相应的渗流厚度在3.90±3.60和8.60±8.10 m范围内）降雨（AR）。对ΔGWS，AR和取水量之间关系的统计解释表明，与考虑中的ΔGWS时间序列的AR变化相比，人为影响（地下水抽取）是主要控制因素（解释方差的99％）。长期补给与年平均降雨量（AAR）之间的关系表明，补给量代表撒哈拉沙漠带跨界含水层中AAR的1.8±0.3％。