WATER SCIENCE AND TECHNOLOGY BOARD The National Research Council (NRC), through its Water Science and Technology Board, will assess opportunities in the hydrologic sciences. This is to include a review of the current status of the subfields of hydrology and of their coupling with related geosciences and biosciences, the identification of promising new frontiers and opportunities for the hydrologic sciences to help improve water and environmental management, and development of the appropriate framework for hydrologic education and research (including funding needs). The study results from an increased awareness by the hydrologic community of the growing need for fundamental advances in hydrologic science to generate solutions to emerging complex problems of water technology, and from the realization that the time has come for hydrology to take its place as a science alongside the other established and recognized geosciences. The study will assess our understanding of the natural reservoirs and fluxes involved in the global hydrologic cycle. The focus will be on continental waters and the natural processes driven by continental waters, such as erosion, sedimentation, vegetation growth, and chemical weathering. Consideration of oceanic, lacustrine, atmospheric, and cryospheric reservoirs will be limited to their interfacial fluxes. The scales of concern will vary from the micro-processes of the soil moisture to the global scale of hydroclimatological change. The study will be carried out by a specially appointed multidisciplinary committee of approximately 16 scientists representing fields ranging from hydrology, geomorphology, geochemistry, and hydrogeology to meteorology, hydroclimatology, and ecosystem science. It is expected that the effort will result in an important reference work on opportunities in the hydrologic sciences. This publication will be of guidance value to science policy makers and government managers--of cultural importance to scientists, educators, and students--and of interest to the informed lay public. The document will transmit the flavor and importance of the hydrologic sciences, identify the needed improvements thereto, and contribute ultimately to improved management of water and the natural environment.