Decision makers and planners need answers to four basic questions to deal responsibly with geologic and other hazards: (a) when willthe hazard occur? (B) what will happen when the hazard occurs? (C) what area will be affected? (D) what can be done to reduce the risk?A perspective for evaluating in comparable terms all hazards at a site and a means for intelligent decision making based on the evaluation is the purpose here. The value engineering approach to geologic hazard risk management is a creative effort concerned with eliminating or modifying those aspects of a system that add costs without reducing risk. The model for risk management, and the risk-based framework, permit estimation of risk costs initially for the existing conditions and subsequently for the variety of alternative responses. Selection of the optimum response to a hazard usually will be based onthe least cost at some acceptable level of risk. Absolute safety isnot possible, and the costs of approaching absolute safety increaseexponentially. Risk costs can be considered to be expected values. Investment decisions are often based on the present worth of the expected values, on the basis of annual discount or interest rates overthe design life of a facility or system. Calculation of present worth values for the variety of possible risk reduction measures permits a systematic assessment of alternatives in comparable terms to facilitate decision making. The value engineering component of this approach to geologic and other hazard risk management requires an integrated, multidisciplinary effort among geologists, engineers, seismologists, meteorologists, and socioeconomists working closely with thedecision makers. This paper appears in transportation research record no. 1288, Geotechnical engineering 1990.
Samenvatting