A probabilistic approach for the rehabilitation of an irrigation network: the fondovalle Ufita district case study

This paper proposes a methodology for upgrading Pressurized Irrigation Distribution Systems (PIDSs) based on the determination of a hierarchy of pipes. This methodology involves two main stages: analyz ing the hydraulic performance, to identify the design flow distribution along the network ; and solving the optimization problem, so as to both ensure the minimum pressure at each node and minimize costs. In the first stage, a number of scenarios considering the simultaneous operation of hydrants within the network are generated. For each scenario, the operating hydrants are identified according to a random distribution. In the second stage, pipes that may have a direct impact on the system s performance are identified and considered as design variables in the optimization process. The methodology focuses on the duplication of pipes to upgrade the PIDS, with the decision variables in the optimization problem being the pipe diameters. The objective of the optimization problem is to reduce the pressure deficit within the PIDS while adhering to budget constraints. The paper also argues that using optimization models for developing PIDS upgrade strategies is particularly advantageous given that they provide the ability to compare different strategies in order to identify the most cost effective and efficient solutions for maintaining and upgrading PIDSs. Moreover, when tested on a real PIDS, the proposed methodology yielded results validating its efficiency in terms of achieving the optimal solutions within reasonable computational time while also giving the minimum total costs required to upgrade the network pipes.