This book is based on my Ph. D. dissertation of Environmental Engineering, Rhode Island University of United States of America titled "Assessing Ground Water Quality and Quantity due Climate Change and Anthropogenic Controlling Factors: case study Saudi Arabia". The format of the dissertation formatted is done as Manuscript format, publication style. The idea is to combine all three papers as a plan to achieve my objectives in this dissertation. CHAPTER 1: MANUSCRIPT : Quantifying temporal variations in water resources of a vulnerable Middle Eastern transboundary aquifer system This manuscript was published in "Journal of Hydrology, 2017." CHAPTER 2: MANUSCRIPT II: Assessment of Critical Modern Recharge to Arid Region Aquifer Systems Using an Integrated Geophysical, Geochemical, and Remote Sensing Approach This manuscript was published in "Journal of Hydrology, 2019". CHAPTER 3: MANUSCRIPT III. Groundwater Quality Patterns and Spatiotemporal Change in Depletion in the Regions of the Arabian Shield and Arabian Shelf This manuscript was published in "Arabian Journal for Science and Engineering (AJSE),2019".