A case study of water distribution network reliability assessment with Mike-Net

This paper describes an hydraulic reliability model that has been developed by University of Basilicata and DHI Water & Environment (Hydroinform in Prague). The model has been described through a case study representing the water distribution system of the city of Matera (Basilicata, Italy). The new module (Reliability Analysis Module) is integrated into the DHI hydraulic simulation model MIKE NET to insure the full technologic transfer of the involved methodologies. This tool permits reliability analysis of complex infrastrucutres and the identification of the critical nodes of the system as well as evaluating the service levels corresponding to different scenarios and the risks due to possible malfunctioning and so it is useful as a support for the decision making process (definition of management criteria and operational rules). The applicability of such approaches is only limited by the capacity of the involved models to reproduce the real hydraulic functioning conditions of the water distribution network analysed. The use of sophisticated simulation instruments facilitates complex analysis that reproduce the spatial-temporal trends of multiple hydraulic and chemical parameters and obtain a wide complex result. The level of analytical detail of the characteristics reproduced by the models makes the interpretation phase difficult and indicate the necessity to synthesize the simulation outputs objectively. Moreover, in this context modeling instruments that evaluate the whole system performance or calculate the reliability of any different elements are the best interpretation aid in undersanding the real bahavior of complex system in any operative conditions (scenarios). The aided outputs model reading permits the identification of the critical system elements and the estimatation of the service levels, thus enabling an evaluation of possible malfunctioning risk and, therefore, is a potent instrument in the selection or definition of optimal management and operation rules.