Ground water hydrology is the process of examining, analyzing and studying the movements, distribution and properties of water present on the surface of the Earth and in aquifers. Some of the key aspects studied under this field are porosity, hydraulic conductivity, hydraulic head, specific storage, water content, hydrodynamic dispersion, retardation by absorption, molecular diffusion, etc. This book is a compilation of chapters that discuss the most vital concepts in the field of ground water hydrology. It outlines the processes and applications of this subject in detail. Some of the diverse topics covered in it address the varied branches that fall under this category. Through this textbook, we attempt to further enlighten the readers about the new concepts in this field.