Book excerpt: The study of water resources crosses disciplinary boundaries, from geography and natural resources, to Earth sciences, environmental studies, and engineering. Since not all students come to the water-resources course with the same mathematical background, Clausen’s effective, practical presentation integrates topics related to water quantity and water quality. He emphasizes fundamental concepts throughout: the qualitative foundations of hydrology needed to understand the hydrologic cycle and water availability, as well as the physical, chemical, and biological principles underlying water quality. Important social-science issues, including water law and regulations, the economic principles of water supply and demand, and sustainable water management, contextualize the material. Abundant illustrations and purposeful examples reinforce chapter content. End-of-chapter problems provide opportunities for readers to practice the calculations needed for real-world applications.