Vulnerability analysis of water distribution systems is a complex task. A review of the literature reveals that there is currently no universally acceptable definition or metric for the vulnerability of water distribution systems. Different definitions are proposed in the literature and some of the most relevant ones have been summarized for the work within STOP-IT, looking at both the quantification of vulnerability metrics and criteria as well as the degree to which these are meaningful and appropriate for water distribution systems, while still computationally feasible.
The Asset Vulnerability Assessment tool (AVAT) of STOP-IT is designed as a standalone tool to be further integrated within the next tasks of the STOP-IT project, helping water utilities to make an initial screening evaluation of the vulnerability of their systems and to focus on a more detailed assessment at the most vulnerable parts of the system. As such, the tool was explicitly designed to only require limited data on the water distribution system, including the layout of the system and one loading (demand) condition.
There are three levels of risk assessment supported by the STOP-IT tools. AVAT belongs mainly to level 2, which incorporates a single scenario assessment with known site-related data, giving a closer estimate on how the utility water distribution system performs under specific events/threats. It can however be used as the first step of both level 1 (expert evaluation based) and level 3 (multiple scenarios) assessments to support the relevant processes.
The required data for AVAT consists of two parts: (1) a steady state hydraulic simulation EPANET file, which runs without any errors, and (2) a MS-Excel file with probability failure data. The output of AVAT consists of tabular data exported to MS-Excel and colour-bar figures.
AVAT was developed in MATLAB® and compiled as a standalone application and as a web application. As such, it mainly relies on MATLAB’s Runtime libraries.
The Asset Vulnerability Assessment Tool (AVAT)