Estratégias para expansão de redes de distribuição de água sob a óptica da teoria de redes complexas

Abstract

Considering the lack of basic drinking water supply services for millions of people in Brazil and worldwide, and in view of the increased demand for drinking water consumption characterized by the global population growth, it is understood that, currently, it is necessary to increase the supply capacity of Water Distribution Networks (WDN), especially in poorer and emerging countries. However, these expansions of Water Supply Systems (WSS) can often, due to the higher demand on the network, generate low system pressures, making it difficult to supply water in adequate quantity and quality. Therefore, aiming to analyze the hydraulic performance and characteristics concerning the connectivity of expansion scenarios of a WDN, in this research, the WSS was modeled as a Complex Network (CN). In order to propose strategies for expanding the capacity of an A, the C-Town network was used as a case study, and several expansion scenarios were implemented based on percentage increases in demand in peripheral nodes of the network. To obtain information about the hydraulic performance of the system the following criteria were considered: pressure uniformity, weighted average age of water above a set limit and hydraulic resilience. The graphs corresponding to the demand increase scenarios were weighted by flow rate and water travel time, in order to obtain, from the application of CN metrics, indicators of the robustness of the WDN. The abstraction of the computational model as CN and the hydraulic analyses of the WDN were done in Python programming language and through, respectively, the packages NetworkX 2.5 and WNTR 0.3.0. In addition, in order to rehabilitate pressures and further improve the hydraulic performance of the system, engineering measures were implemented and budgeted for all expansion scenarios. Finally, in order to obtain optimal scenarios, all scenarios were ranked using the TOPSIS multi-criteria analysis method. As results, it was obtained that, in general, the expansion scenarios that generated the lowest risks of failure and damage to the water distribution network, considering also the metrics of complex networks, are located in Sector 1 and the scenarios that improved the most with the application of engineering measures were the scenarios in Sector 3.