Volume II, 'Examples', illustrates the application of many of the principles, concepts and techniques introduced in Volume I as applied to two idealized, but realistic case examples. These examples more fully develop the concepts as applied to the risk problems common in water resources investment planning.

Reducing flood damage is a complex task that requires multidisciplinary understanding of the earth sciences and civil engineering. In addressing this task the U.S. Army Corps of Engineers employs its expertise in hydrology, hydraulics, and geotechnical and structural engineering. Dams, levees, and other river-training works must be sized to local conditions; geotechnical theories and applications help ensure that structures will safely withstand potential hydraulic and seismic forces; and economic considerations must be balanced to ensure that reductions in flood damages are proportionate with project costs and associated impacts on social, economic, and environmental values. A new National Research Council report, Risk Analysis and Uncertainty in Flood Damage Reduction Studies, reviews the Corps of Engineers' risk-based techniques in its flood damage reduction studies and makes recommendations for improving these techniques. Areas in which the Corps has made good progress are noted, and several steps that could improve the Corps' risk-based techniques in engineering and economics applications for flood damage reduction are identified. The report also includes recommendations for improving the federal levee certification program, for broadening the scope of flood damage reduction planning, and for improving communication of risk-based concepts.

Ronald M. North President Universities Council on Water Resources People sense intuitively that the world in which we live is not free of risk. Every decision, every action, even the refusal to either act or decide involves some element of risk. Perhaps, because we accept relatively low levels of risk in our daily activi ties, we tend to minimize the existence of risk and thereby fail to include risk assessment in those decisions and actions which could be improved through a risk assessment process. However, our casual approach to risk assessment seems to stem largely from the diffi culties inherent in measuring risk rather than from any lack of cognizance of the existence of risk. This conclusion is evidenced by the many statements in official documents relating to planning and evaluation which suggest that risk assessments should be con ducted but do not provide the mechanism for such assessments nor do they encourage their consideration in the decision making process. This conference on Risk/Benefit Analysis in Water Resources Planning and Management is notable because it attempts to identify and evaluate the mechanisms available for risk assessment which might be useful in water resources planning and management efforts. These proceedings bring together the thoughts of professional per sons who have struggled with the problems of risk assessment and who have contributed to the refinement of both theoretical and pragmatic solutions for the improvement of risk assessment processes.

This book reviews the U.S. Army Corps of Engineers' (USACE) investigations of flood control options for the American River basin and evaluates flood control feasibility studies for the watershed, with attention to the contingency assumptions, hydrologic methods, and other analyses supporting the flood control options. This book provides detailed comments on many technical issues, including a careful review of the 1991 National Research Council report American River Watershed Investigation, and looks beyond the Sacramento case to broader questions about the nation's approach to flood risk management. It discusses how to utilize information available about flood hazard reduction alternatives for the American River basin, the potential benefits provided by various alternatives, the impacts of alternatives on environmental resources and ecosystems, and the trade-offs inherent in any choice among alternatives which does not lie in the realm of scientists and engineers, but in the arena of public decisionmaking.

35 leading multi-disciplinary scientists with international reputations provide reviews of topical areas of research on uncertainty and reliability related aspects of water resource systems. The volume will be valuable for graduate students, scientists, consultants, administrators, and practising hydrologists and water managers.