From a wider national perspective, GCIP does not address hydroclimatic phenomena that are characteristic of the semiarid U.S. Southwest, a region where the availability of water is a critical resource issue as well as a challenging scientific problem. Applying the methodologies and technical facilities developed for GCIP to a study of the Colorado River basin and surrounding mountain regions is a challenge for the future.

GCIP accomplishments include the following: (1) the most comprehensive accounting to date of atmospheric and surface water and energy budgets on a continental scale; (2) the advancement of land surface parameterizations and atmospheric models incorporating hydrologic principles; (3) the development of new regional land surface data assimilation methods using new high-resolution precipitation observations; (4) the development of a comprehensive GCIP data set that will be a basic support for twenty-first century developments in remote sensing and data assimilation; and (5) a new paradigm for water resources management utilizing new operational weather prediction analyses and forecasts. When fully implemented, GCIP can be expected to strengthen our nation's capability for climate prediction and water resource management. It will provide a sound basis for hydroclimatological research at the beginning of the twenty-first century.