The eminent global hydrologist R. L. Nace (1969, p. 11)noted that “the story of the growth of civilization and science could be written largely in terms of human concern with water.” That quotation applies fittingly to the North American continent, whose economic and social development are intimately tied to its natural water supply. Demographic, agricultural, and industrial expansion have evolved largely around opportunities proffered by the continent’s surface, ground, and soil water.
Cultural and economic gains attributable to water development have been aided by coincident advances in knowledge of the hydrology and geology of the continent, accompanied by parallel progress in understanding of basic principles of the science of geohydrology. North American scientists have exercised leadership in both applied and basic geohydrological investigation. The significant roles of water in the continent’s geophysical and geochemical processes are only now being more fully recognized and integrated into the earth sciences, with both scientific and pragmatic benefits. It is now understood that water, whether in its liquid, vapor, or solid (ice) form, fulfills many fundamentally important physical and chemical functions in virtually all Earth environments.
This overview chapter is concerned primarily with the geohydrology of North America, and most particularly with the natural occurrence of fresh surface and ground water of the continent, with less attention to practical water-supply and water-use aspects. This is true also for Wolman and Riggs (1989) and Back and others (1988) of this series of volumes. Those two volumes provide, respectively, comprehensive descriptions of the surface and ground-water hydrology of the continent.