Hydrologic Science Priorities for the U.S. Global Change Research Program -- Copyright -- Preface -- Contents -- Executive Summary -- 1-Setting Priorities -- 2-Science Foundations and Basic Processes -- PREDICTABILITY AND VARIABILITY OF REGIONAL AND GLOBAL WATER CYCLES -- Predictable Patterns of Seasonal-to-Interannual Variability -- Sources of Long-Term Variability -- Linking Measurements and Understanding across Scales -- COUPLING OF HYDROLOGIC SYSTEMS AND ECOSYSTEMS THROUGH CHEMICAL CYCLES -- Characterization of Water and Chemical Pathways -- Interactions between Hydrologic Systems and Ecosystems -- Human Disturbances of Hydrologic Systems and Ecosystems -- 3-Measurement and Data Strategies -- MAINTAINING AND UPGRADING GROUND-BASED NETWORKS -- INTEGRATION OF REMOTE SENSING WITH GROUND-BASED MEASUREMENTS -- DATA INTERPRETATION: SYNERGY IN MODELING AND MEASUREMENT -- SUPPORTING LONG-TERM EXPERIMENTAL SITES -- DATA ACCESSIBILITY AND QUALITY CONTROL -- 4-Applications and Knowledge Transfer -- APPLICATIONS AND USER INTEGRATION -- EDUCATION AND KNOWLEDGE TRANSFER -- 5-Conclusions and Recommendations -- References -- Appendix Biographical Sketches of Committee on Hydrologic Science.