Evaluation of Flood Forecasting-Response Systems

When the objective of operating a flood forecasting-response system is to reduce damage caused by flooding, rather than to provide accurate and timely flood forecasts, improvements and changes to the system must be evaluated considering all components of the system and their interactions. For this purpose the methodology considers the following components of the system: (1)The hydrometric system; (2)the forecasting model; (3)the dissemination system; and (4)the decision model used by the flood-plain dweller and his protective system. Quantification is accomplished by a mathematical model that enables flood forecasting systems to be evaluated on the basis of expected reduction in damage due to the use of the system. Uncertainties in the forecast are handled in a decision theoretic manner that enables the calculation of an optimal response to a forecast. Comparison of optimal and nonoptimal responses illustrates the importance of considering the response when examining the effectiveness of flood forecasts.