Optimal reservoir sizing in on-demand irrigation networks: Application to a collective drip irrigation network in Spain

Optimal reservoir sizing in on-demand irrigation networks with a minimum cost was obtained, taking into account the variability of pressure and flow rate demanded by the network during the irrigation season. With this aim, a model called DRODIN (Design of Reservoirs of regulation in On-Demand Irrigation Networks) was developed under a holistic approach. That obtain the optimal design and management (minimum total annual cost, C-T) of the water abstraction systems in an integrated manner to include the aquifer along with the pumping station, reservoir and pumping and distribution pipes in a collective irrigation network. This tool has been applied to an on-demand irrigation network located in Spain with 171 ha of drip irrigation in vineyard and olive crops. The optimal reservoir volume is approximately 5000 m(3), and the C-T for water lift (WL) = 100 m (the most common case for this aquifer) is 325 (sic) ha(-1) yr(-1). The energy cost is the primary component of C-T, both in the abstraction and the water supply to the irrigation network, representing between 57% and 80%. The operation of the pumping station determines the size of the reservoir and the annual costs of the water supply to the network for a given water supply guarantee. The CT increases linearly with the WL, primarily because of the increase in energy costs (C-e), although there is a clear relation between the investment costs (C-e), C-e and the reservoir size, which is only possible to analyse with tools such as DRODIN. (C) 2016 IAgrE. Published by Elsevier Ltd. All rights reserved.