Simultaneous Analysis of Monthly Water Consumption, Air Temperature and Water Supply Network Pressure Using Copula Functions, Case Study: Zone No. One of Isfahan City

Analysis and control of water consumption in water supply and distribution networks is important issues, given the country's climatic conditions and the fact that they can be of great help to designers and managers of water resources. Copula functions are suitable tools for multivariate analysis that do not have the limitations of classical multivariate distribution functions. In this study, two and three variables of factors affecting water consumption prediction using the copula functions of the Archimedean family in zone one of Isfahan city were investigated. The results showed that based on the goodness-of-fit criteria and Q-Q plot diagram, Frank joint function between two variables of monthly water consumption and network pressure for this region was selected as the superior function with a model parameter of -2.02 and in the three variables Gamble joint function was selected with correlation parameters 1, 1.05 and 1 for all cases. Considering the best copula function, the conditional cumulative distribution functions of the two variables and the conjunctive, seasonal and conditional return periods were analyzed to predict water consumption, which can be determined according to the specified return period and the numbers obtained in used managerial planning and finally the three-variable analysis was not evaluated due to inadequate correlation.