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The correct management of urban water networks have to be supported by monitoring and estimating water quality. The infrastructure maintenance status and the possibility of a prevention plan availability influence the potential risk of contamination. In this context, the Contamination Source Identification (CSI) models aim to identify the contamination source starting from the concentration values referring to the nodes. This paper proposes a methodology based on Dynamics of Network Pollution (DNP). The DNP approach, linked to the pollution matrix and the incidence matrix, allows a topological analysis on the network structure in order to identify the nodes and paths most sensitive to contamination, namely those that favor a more critical diffusion of the introduced contaminant. The procedure is proposed with the aim of optimally identifying the potential contamination points. By simulating the contamination of a synthetic network, using a bottom-up approach, an optimized procedure is defined to trace back to the chosen node as the most probable contamination source.

A smart management of water distribution networks requires the infrastructure to be operated with high efficiency. For many years the hydraulic modelling of water distribution networks has been conditioned by the scarce availability of quality data but the technological advances contributed to overcome this drawback. The present work describes the research activity carried out about water distribution network modelling, focusing on model construction and calibration. For this purpose, WaterNetGen, an extension of the Epanet hydraulic simulation software, has been used. EPANET simulation model assumes that the required water demand is always fully satisfied regardless the pressure (Demand Driven Analysis - DDA), while WaterNetGen has a new solver assuming that the required water demand is only fully satisfied if the pressure conditions are adequate (Pressure Driven Analysis - PDA). A comparison between the software outputs is the starting point for a new method of allocating and distributing water demand and water losses along the network, leading to model results closer to the measurements obtained in the real network. The case study is the water distribution network of the municipality of Nicotera, in Southern Italy.

Defining criteria for correct distribution of water resource is a common engineering problem. Stringent regulations on environmental impacts underline the need for sustainable management and planning of this resource usage, which is sensitive to many parameters. Optimization models are often used to deal with these problems, identifying the optimal configuration of a Water Distribution Network (WDN) in terms of minimizing an appropriate function propotional to he construction cost of the WDN. Generally, this cost function increases as the distance between the source-user connection increases, therefore in minimum cost optimization models is important to identify minimum source-user paths compatible with the orography. In this direction, the methodology presented in the present work proposes a useful approach to find minimum-length paths on surfaces, which moreover respect suitable hydraulic constraints and are therefore representative of reliable gravity water pipelines. The application of the approach is presented in a real case in Calabria.

The proper allocation of water resources is a very important practical problem in the field of water network planning. Optimization models that are expeditious and easy to use for all stakeholders of the sector play an important role for water resource management. The present work resumes and reviews a least-cost optimization model proposed by our group (Maiolo and Pantusa in Water Sci Tech-W Sup. https://doi.org/10.2166/ws.2015.114 , 2016), able to design a water distribution network with multiple supply sources and multiple users. This approach requires of solving an optimization problem based on a nonlinear objective function which is proportional to the cost of the water distribution network. The cost of pre-existing pipelines is considered null. A more realistic scenario, able to consider the maximum flow rate allowed for existing sources-users connections, is considered here. In order to illustrate the usefulness and flexibility of the proposed approach, an application of the model to the real case of the province of Croton, Southern Italy, is presented.

The main objective of a water distribution network is to provide water to users in compliance with quality and service standards under different conditions. The ability to meet the water demand at the nodes, under the required pressures head, depends on many characteristic factors of the water network, such as various infrastructural components. A water distribution network is a complex system consisting of numerous structural elements and dependent by several factors. Resilience, robustness and vulnerability are of great interest, for these systems, in relation to the possible failure conditions which may compromise the network&rsquo, s ability to fulfill the project conditions. Vulnerability measures how much the network is fragile: a higher value of vulnerability means that the network is prone to fail in achieving the project conditions. In the present work, a new vulnerability measure based on a topological approach is proposed. A first application of the proposed vulnerability measure on two water networks known in the literature is described, and the obtained results are compared with other performance indices showing a significant correlation.