Investigating Groundwater Systems on Regional and National Scales -- Copyright -- Preface -- Contents -- Executive Summary -- 1 Groundwater and Society -- A CRITICAL RESOURCE -- Drinking and Irrigation Water -- Streamflow and Ecosystems -- A THREATENED RESOURCE -- AN OVERDEVELOPED RESOURCE -- Regional Subsidence -- Salt-Water Intrusion -- Resource Depletion -- THE NECESSITY FOR CONJUNCTIVE MANAGEMENT -- CONCLUSIONS -- 2 Approaches to Synthesis of Groundwater Issues at the Regional Scale -- USGS GROUNDWATER PROGRAMS-PAST AND PRESENT -- The Changing Arena of Hydrogeology -- Regional Aquifer-System Analysis (RASA) Program -- National Water-Quality Assessment Program -- Groundwater Monitoring Networks -- Other Current USGS Programs -- Ground-Water Resources Program -- NEW OPPORTUNITIES AND MANDATES -- An Emphasis on Sustainability -- Alternative Meanings of "Regional" -- PROPOSED FRAMEWORK FOR REGIONAL-SCALE GROUNDWATER STUDIES -- Regional Groundwater Assessment -- Regional Groundwater Science -- Example: Middle Rio Grande -- Regionalization -- CONCLUSIONS -- 3 Institutional Integration and Collaboration -- EXTERNAL COLLABORATION -- Rationale and Benefits -- Conditions for and Obstacles to Collaboration -- INTERNAL COLLABORATION -- Federal-State Cooperative Water Program -- National Water-Quality Assessment Program -- Toxic Substances Hydrology Program -- CONCLUSIONS -- 4 Scientific Issues -- AQUIFER MANAGEMENT -- Scientific and Management Issues -- USGS Roles in Aquifer Management -- NATURAL GROUNDWATER RECHARGE -- Scientific and Management Issues -- USGS Roles in Groundwater Recharge -- GROUNDWATER QUALITY AND MOVEMENT IN SURFICIAL MATERIALS -- Scientific and Management Issues -- USGS Roles in Surficial Material Hydrogeology -- GROUNDWATER-SURFACE WATER INTERACTIONS -- Scientific and Management Issues.

USGS Roles in Groundwater-Surface Water Interactions -- GROUNDWATER IN KARST AND FRACTURED AQUIFERS -- Scientific and Management Issues -- USGS Roles in Karst and Fractured-Rock Studies -- CHARACTERIZATION OF SUBSURFACE HETEROGENEITY -- Scientific and Management Issues -- USGS Roles in Characterization of Subsurface Heterogeneity -- NUMERICAL MODELING -- Scientific and Management Issues -- USGS Roles in Numerical Modeling -- FACILITATING USE OF GROUNDWATER INFORMATION IN DECISION-MAKING -- Quantifying and Reducing Uncertainty in Predictions -- Scaling Available Information to the Regional Level -- Developing Decision-Making and Risk Models for Groundwater Use -- CONCLUSIONS -- 5 Delivery and Accessibility of Groundwater Data -- USERS OF GROUNDWATER DATA -- CONTENT OF GROUNDWATER DATA -- FORMAT OF GROUNDWATER DATA -- Web-Based Data Sets on a National Scale -- Web-Based Data Sets on Regional Scales -- Recommendations for Internet-Based Groundwater Information Delivery -- CONCLUSIONS -- 6 Conclusions and Recommendations -- SCIENTIFIC ASSESSMENT OF CRITICAL GROUNDWATER ISSUES -- REGIONAL AND NATIONAL OVERVIEWS -- ACCESS TO GROUNDWATER INFORMATION -- METHODS DEVELOPMENT -- References -- Appendix A U.S. Geological Survey Programs that Support Groundwater Resources Studies -- Ground-Water Resources Program -- National Water-Quality Assessment Program -- National Cooperative Geologic Mapping Program -- Federal-State Cooperative Water Program -- Toxic Substances Hydrology Program -- National Research Program -- Appendix B Biographical Sketches of Committee Members.