GRACE gravity variation recovery and InSAR-derived ground displacement data show promise in supporting and assessing groundwater management policies. However, GRACE system's resolution is too low, and the inversion of InSAR data into volume of groundwater storage loss requires extensive and often unavailable lithological data. Here we present how InSAR can be used to constrain and spatially focus GRACE-derived groundwater mass loss to depletion areas, reducing the gap between the GRACE scale and the typical water management scales. While we highlight the tremendous potential of a fully geodetic, quantitative, and high resolution mapping of groundwater storage loss, we also point out the crucial need for producing guidelines on the proper GRACE solution to use for any study area and/or application.In order to illustrate the GRACE/InSAR combination procedure, we present a case study in Central Mexico, where groundwater depletion of ~ 5000 Million Cubic Meters per year (MCM/yr) is reported by the water governance agencies and is well documented in the scientific literature. However, in this region, not all GRACE solutions provide reasonable groundwater depletion estimates. Using two of them, an inversion is performed to focus the groundwater-related GRACE signal over different mass distribution maps. Several mass distributions are tested, including two from InSAR-derived aquifer compaction mapping. The results show that the regions of Mexico City and Bajio, an agricultural and industrial corridor 250 km North of Mexico City, are the main contributors to the regional groundwater depletion. The mass distribution map produced directly from InSAR leads to results closer to official groundwater budgets than the others tested.

中文翻译：

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使用联合 GRACE/InSAR 方法在水资源管理尺度上定量绘制地下水枯竭情况

GRACE 重力变化恢复和 InSAR 衍生的地面位移数据在支持和评估地下水管理政策方面显示出前景。然而，GRACE系统的分辨率太低，将InSAR数据反演为地下水储存损失量需要大量且往往无法获得的岩性数据。在这里，我们介绍了如何使用 InSAR 将 GRACE 衍生的地下水质量损失约束和空间聚焦到枯竭区，从而缩小 GRACE 尺度与典型水资源管理尺度之间的差距。虽然我们强调了对地下水储存损失进行完全大地测量、定量和高分辨率绘图的巨大潜力，但我们也指出了制定用于任何研究区域和/或应用的适当 GRACE 解决方案指南的关键需求。为了说明 GRACE/InSAR 组合程序，我们在墨西哥中部进行了一个案例研究，水治理机构报告了每年约 50 亿立方米 (MCM/yr) 的地下水枯竭，并在科学文献中有详细记录。文学。但是，在该地区，并非所有 GRACE 解决方案都能提供合理的地下水消耗估算值。使用其中的两个，执行反演以将与地下水相关的 GRACE 信号聚焦在不同的质量分布图上。测试了几个质量分布，包括两个来自 InSAR 衍生的含水层压实测绘。结果表明，墨西哥城和墨西哥城以北 250 公里的农业和工业走廊 Bajio 地区是区域地下水枯竭的主要贡献者。