Paper Title
Uncertainty Propagation In Water Management Decisions A Monte Carlo Approach

Abstract
Thispaper is devoted to the analysis of uncertainties in hydrologic series and their impact on water resources management decisions. The methodology is based on Monte Carlo simulation, where critical parameters on the system input are sampled from suitable probability distributions in order to analyze the probability distribution of system outputs. The uncertainty analysis follows the traditional approach of water resources management studies: from rainfall to runoff and from runoff to performance of water supply system. Uncertainty on the hydrologic series is analyzed by studying the rainfall-runoff relationship. The results of the uncertainty experiment on hydrological series are then used on risk analysis of water supply systems by running a water resources model with the ensemble of hydrological series. The procedure is applied to three water resources systems in the Duero basin (Spain). Results show that confidence intervals for relevant hydrologic and decision variables are very sensitive to uncertainties in model input. Keywords� water resources; reservoir management; Monte Carlo; uncertainty; decision making