Comprising 44 chapters by authors from 22 countries, this book focuses on the hydrogeology of fractured environments. This compendium discusses the key issues, methodologies, and techniques in the field of hydrogeology of fractured (hard) rocks, summarizing results achieved in recent years as well as stimulating ideas and considerations on future investigations needed to advance our understanding of these vital natural systems. It covers hydrogeologic environment of fractured rocks; conceptual models, groundwater flow, and resources in fractured rocks; groundwater quality in fractured rocks; investigation and interpretation methods; anthropogenic impacts; and numerical modelling.