The International Hydrological Decade (which ended in 1975) led to a revival of hydrological sciences to a degree which, seen in retrospect, is quite spectacular. This research programme had strong government support, no doubt due to an increased awareness of the role of water for prosperous development. Since water quality is an essential ingredient in almost all water use, there was also a considerable interest in hydrochemistry during the Decade. As many concepts in classical hydrology had to be revised during and after the Decade there was also a need for revising hydrochemistry to align it with modern hydrology. A considerable input of fresh knowledge was also made in the recent past by chemists, particularly geochemists, invaluable for understanding the processes of mineralization of natural waters. With all this in mind it seems natural to try to assemble all the present knowledge of hydrochemistry into a book and integrate it with modern hydrology as far as possible, emphasizing the dynamic features of dissolved substances in natural waters. Considering the role of water in nature for transfer of substances, this integration is essential for proper understanding of processes in all related earth sciences. The arrangement of subjects in the book is as follows. After a short introductory chapter comes a chapter on elementary chemical principles of particular use in hydrochemistry.

This book comprises the selected papers from the 1st Springer Conference of the Arabian Journal of Geosciences (CAJG-1), Tunisia 2018. The volume is of interest to all researchers and practitioners in the fields of Hydrology, Hydrogeology, Hydrochemistry, Water Resources and Hydrologic Engineering. Water is a dynamic, finite, and vulnerable but resilient natural resource to be protected in an environmentally sustainable manner. Water systems in different frameworks requires a comprehensive understanding of climatology, geology, hydrogeology, hydrochemistry, hydrodynamics, and surface hydrology. In addition, it is highlighted the role of the variability and climate change in water systems. Furthermore, water has a vital significance to the entire socio-economic sector. This volume offers an overview of the state-of-the-art related to water science and technology in model regions in Europe, Africa, Middle East, Asia and America, but mainly focuses on the Mediterranean environment and surrounding regions. It gives new insights on characterisation, evaluation, quality, management, protection, modelling on environmental hydrology, groundwater, hydrochemistry, sustainable water resources studies and hydrologic engineering approaches by international researchers. Main topics include: 1. Hydrology, Climatology and Water-Related Ecosystems 2. Hydrochemistry and Isotopic Hydrology 3. Groundwater Assessment and Management: mapping, exploration, abstraction and modelling 4. Water Resources Sustainability and Climate Change 5. Hydrologic Engineering and Urban Groundwater

Water is the basis of all life. Preservation of aquatic ecosystems and protection of water resources thus are among the most important goals of a sustainable development. The quality of water is mainly determined by its constituents, the entirety of the substances dissolved or suspended in water. To assess the water quality on a sound basis requires in-depth knowledge about the occurrence, behavior and fate of these constituents. That explains the importance of hydrochemistry (also referred to as water chemistry or aquatic chemistry) as a scientific discipline that deals with water constituents and their reactions within the natural water cycle and within the cycle of water use. This textbook introduces the elementary basics of hydrochemistry with special focus on reaction equilibria in aquatic systems and their mathematical description. It is designed as an introductory textbook for students of all environment-related courses who are beginning their hydrochemical education. Only minor knowledge in General Chemistry is required to understand the text. The book is also suitable for continuing education. Topics discussed in this textbook include: structure and properties of water, concentration measures and activities, colligative properties, basics of chemical equilibria, gas-water partitioning, acid/base reactions, precipitation/dissolution, calco-carbonic equilibrium, redox reactions, complex formation, and sorption. The text is supplemented by numerous figures and tables. More than 50 examples within the text as well as more than 60 problems to be solved by the reader support the acquiring of knowledge. Complete and detailed solutions to all problems are given in a separate chapter.

Water is the basis of all life. Preservation of aquatic ecosystems and protection of water resources thus are among the most important goals of a sustainable development. The quality of water is mainly determined by its constituents, the entirety of the substances dissolved or suspended in water. To assess the water quality on a sound basis requires in-depth knowledge about the occurrence, behavior and fate of these constituents. That explains the importance of hydrochemistry (also referred to as water chemistry or aquatic chemistry) as a scientific discipline that deals with water constituents and their reactions within the natural water cycle and within the cycle of water use. This textbook introduces the elementary basics of hydrochemistry with special focus on reaction equilibria in aquatic systems and their mathematical description. It is designed as an introductory textbook for students of all environment-related courses who are beginning their hydrochemical education. Only minor knowledge in General Chemistry is required to understand the text. The book is also suitable for continuing education. Topics discussed in this textbook include: structure and properties of water, concentration measures and activities, colligative properties, basics of chemical equilibria, gas-water partitioning, acid/base reactions, precipitation/dissolution, calco-carbonic equilibrium, redox reactions, complex formation, and sorption. The text is supplemented by numerous figures and tables. More than 50 examples within the text as well as more than 60 problems to be solved by the reader support the acquiring of knowledge. Complete and detailed solutions to all problems are given in a separate chapter.