Water Quantity and Quality Risk Assessment of Urban Water Supply Systems with Consideration of Uncertainties

Sufficient drinking water supply with acceptable quality has been one of the important challenges that decision makers in urban water systems have always faced. Different natural, non-natural and operational hazards, may threaten different components of urban water systems and they may lead to irreversible consequences. In this research, Fuzzy Hierarchical Risk Assessment model has been presented which is capable of considering the complexities and uncertainties in urban water systems. Different stages of the proposed modeling process include systems components and threatening hazards identification, analyzing the information (i.e. probability of hazard, consequences of hazard and components vulnerabilities) in a fuzzy environment and finally aggregation of estimated risks in different parts of water supply systems and ranking them. Another risk analysis method has been introduced which is based on Monte Carlo simulation using crisp numbers and then results of these models have been compared together for an example of urban water supply system. Presented approaches in this paper, can be very useful for real world risk-based decision making in urban water supply management with respect to the probable hazards