Investigating the Risk of Garmsar Water Distribution Network through Binary and TOPSIS Methods Using GIS

By increasing the urban populations in the country and development of cities on the one hand and the continuation of the drought and the reduction of precipitation on the other hand, supplying of drinking water has become one of the most important challenges in water resource management. Therefore, the need for preventive activities to reduce losses due to the casualties in water supply pipes has become one of the main needs of any water supply systems. In this study, the present state of the water distribution network of Garmsar city is investigated and by compositing descriptive and spatial information and also remote sensing information during development, the risk of water distribution network in the city is investigated using TOPSIS and Binary methods. The risk map of breakage or failure in pipes due to decay, burst, pressure, and leakage is plotted. The results showed that the TOPSIS method with validity percentage of 63 is more reliable comparing the Binary method with validity percentage of 45 in predicting events in the water distribution network. Also, according to the risk map of the pipes, the length of high risk-taking pipes are about 12000 meters. The total costs for purchasing and running the pipes will be less than the costs of the losses in the water distribution system. This cost is additional to the unaccounted costs for water and must be paid just to rehabilitate the system.