Analysis of intermittent supply systems in water scarcity conditions and evaluation of the resource distribution equity indices

Generally, urban water distribution shortage situations are solved by introducing discontinuous service and rationing the available water resources. This approach is widely adopted, not only in developing countries but also in developed ones, for solving short term scarcity conditions which can be caused by unpredicted drought periods. Intermittent distribution has the advantage of requiring small financial efforts but it leads to network operating conditions that are very far from the usual design ones. With the aim to analyse and describe the water supply network behaviour in intermittent conditions, a network hydraulic model has been set up in which both user and manager dependent regulation structures have been schematised (pumps, private reservoirs, etc.). The analysis allowed evaluating network performance introducing several control strategies so suggesting operational plans for reducing the impact of water scarcity events on population and improving resources distribution equity. The presented model has been applied to the water distribution network of Palermo (Italy).