BL A practical teaching courseBL Takes an environmental approach to hydrologyThis is a textbook in environmental hydrology–a field of study concerned with the basic system of water circulation and patters of runoff and the major ways in which human occupation of Earth alters both processes and pattersn. It focuses on the river basin or catchment unit not only because of its geographical appeal but because it is the basic experimental and data-gathering unit, and the fundamental unit for water management.The book explores a considerable number of methodological frameworks. Most of these are scientific; an acceptable replacement for problem-solving by data collection, analysis, and prediction has yet to be found. However, it also considers non-digital values–attitudes, preferences, policies, laws–especially in the case of the freshwater environment, where key data are still relatively scarce.Having developed a holistic approach to river basins, the author concludes by considering the utility of our current knowledge of environment hydrology to provide the reader with a practical response to the conservation of fresh water.