Decision Support Systems in Rehabilitation Planning of Water Pipe Networks

The pursuance of a preventive strategy in the planning of rehabilitation measures requires a detailed inventory as well as state analysis of the existing water pipe network. Once they have been adjusted accordingly, data management systems, such as relational data bases and geo-information systems, can serve as valuable tools in decision making. To locate weak spots in water pipe networks and, as a consequence, to plan their rehabilitation based on their current state, a desktop GIS was employed as decision support system. The data of the urban water pipe network of the city of Graz were available for the study. A crucial part of any comprehensive rehabilitation scheme is the assessment of the long-term need for rehabilitation. To this end, the ageing model according to HERZ was integrated into an Access data base. It provided the mathematical foundation of the decision support system PiReP (Pipe Rehabilitation Planning System), which was developed in the course of the study. It can be used for the administration of inventory data and recorded damage, the grouping of pipes displaying similar fatigue behaviour, the determination of trends in failure rates as well as for the calibration of ageing functions of groups of pipes, long-term rehabilitation requirement forecasting and scenario analyses.