Assessing the correlation between service flexibility and the cost of modernized large-scale pressurized irrigation systems: a perspective of resilience

Abstract

Traditional static design approaches are often challenged by multifaceted uncertainties such as climate change, future demand, supply options, high-tech opportunities as well as budgetary constraints. However, robust approaches that incorporate the option of flexibility combined with optimization advances are likely to meet threshold performance criteria with the least amount of associated expenses. To this aim, several countries have started the process of modernizing their irrigation schemes, foreseeing their on-demand operation. The re-modernized schemes are facing the challenge of the inadequacy of the service reported by the users/ratepayers, whose livelihoods are threatened by it as they mainly rely on agricultural production, and the sustainability of the modernization process. This study develops an adaptive framework that applies a two-pronged approach: it incorporates, on the one hand, a qualitative analysis through a rapid appraisal procedure (RAP) that fills the big data-gap issue, and a top–down approach on the other hand, mainly based on an iterative process that assesses the correlation between the flexibility of the service provided under uncertainties, as well as the financial feasibility. The latter is associated with the sensitive parameters of Clement’s first formula mainly used in the Mediterranean Region to design on-demand irrigation systems, and more specifically: the elasticity assigned at the feed hydrant of the distribution network, the coefficient of utilization of the network in the peak period, and the quality of the service. Applied to a Tunisian case study, the results clearly show that when adequately combining the flexibility levels of these parameters, an optimal quality service may be achieved with an average cost increment ranging between 13 and 16%, with a view of proactively increasing the resilience of the irrigators’ community.