## 2 Background Fundamentals
### Randomized Low-Rank Approximations
Conception and design, material preparation, data collection, and analysis were performed by [PERSON] and A.A. All authors have read and agreed to the published version of the manuscript. This research was funded by the School of Information Technology and Engineering, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India. Not applicable. The the authors declare no conflict of interest. The following abbreviations are used in this manuscript: \begin{tabular}{l l} UNICEF & United Nations Children's Fund \\ NASA & National Aeronautics and Space Administration \\ GRACE & Gravity Recovery and Climate Experiment \\ GWL & Groundwater level \\ AI & Artificial intelligence \\ RF & Random forest \\ ML & Machine learning \\ ANN & Artificial neural network \\ \end{tabular} 

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