Feasible Sanitary Sewer Network Generation Using Graph Theory

Abstract

A graph theory-based methodology is proposed for the sewer system optimization problem in this study. Sewer system optimization includes two subproblems: layout optimization and hydraulic design optimization, which can be solved independently or solved simultaneously. No matter which method is chosen for the solution of the optimization problem, a feasible layout that satisfies the restrictions of the sewer system must be obtained in any step of the solution. There are two different layout options encountered: the layouts containing all sewer links and the layouts not containing all sewer links. The method proposed in this study generates a feasible sewer layout that contains all sewer links and satisfies all restrictions of a sanitary sewer system by using graph theory without any additional strategies unlike other studies. The method is applied to two different case studies. The results of the case studies have shown that graph theory is well applicable to sewer system optimization and the methodology proposed based on it is capable of generating a feasible layout. This study is expected to stimulate the use of graph theory on similar studies.

The Applications of Graph Algorithms to Modeling of Integrated Urban Water Management System

“…These are hypergraphs, the properties and advantages of which are already used in modeling complex systems, including in chemistry, electrical engineering and mechanics. Hanging Gardens Algorithm stormwater [31][32][33] Loop-By-Loop Algorithm stormwater [31,30], sanitary sewage [21,55] Genetic Algorithm stormwater [42,51,52], sanitary sewage [21,56], water distribution system [59,60] Bayesian Networks Algorithm sanitary sewage [58] Dijkstra's Algorithm stormwater [53,54], sanitary sewage [21], water distribution system [61,62] Tree-Growing Algorithm sanitary sewage [56,57]…”

“…They come out of the apartments, as well as business or corporate buildings. In general, sanitary sewerage is highly polluted, mainly due to the content of human excreta and food leftovers [21].…”

“…The loopby-loop cutting algorithm is applied to the layout production to minimize the system construction cost. By means of this algorithm, the restrictions and bounds of the sewer networks layout are immediately met by, step-by-step, opening the loops of an initial base graph [21,55]. The Dijkstra's algorithm is employed to obtain the layout of a sanitary sewerage system by applying the shortest-path spanning tree and minimum spanning tree algorithms [21].…”

“…The genetic algorithm in sanitary sewage is applied as the optimization tool. The target is to minimize the total cost, to minimize the residence time of the water within the system and also to maximize the network reliability metric [21,56].…”

A Simplified Sanitary Sewer System Generator for Exploratory Modelling at City-Scale

“…One way to consider such uncertainties is to explore the consequences of system alternatives under different scenarios in a long-term planning process. Such an approach has been applied to explore potential urban drainage transition pathways (Urich et al 2013, Baron et al 2015, for layout and size optimisation of sewer networks (Duque et al 2016, Bakhshipour et al 2019, Moeini and Afshar 2019, Turan et al 2019, Duque et al 2020, Zaheri et al 2020, operation and maintenance assessment (Marzouk andOmar 2013, Petit-Boix et al 2015), virtual case study generation of urban water infrastructure (Urich et al 2010), quantification of decentralised water management opportunities (Bach et al 2013), risk and vulnerability assessment (Sitzenfrei et al 2011, Meijer et al 2018, among others.…”