Optimization of groundwater abstraction system and distribution pipe in pressurized irrigation systems for minimum cost

A tool named DOPIR (Dimensioning Of Pressurized IRrigation) was developed to optimize the process of water abstraction from an aquifer for pressurized irrigation systems. This tool integrates the main factors throughout the irrigation process, from the water source to the emitter. The objective is to minimize the total cost of water abstraction and application (C _T) (investment (C _a) + operation (C _op) per unit of irrigated area according to the type of aquifer, crop water requirement and electricity rate periods. To highlight the usefulness of this tool, DOPIR has been applied to a corn crop in Spain with a permanent sprinkler irrigation system, considering two types of aquifer: confined and unconfined. The effects of parameters such as the static water table in the aquifer (SWT), irrigated area (S), number of subunits in the plot (NS), sprinkler and lateral pipe spacing, and average application rate (ARa) on C _T have been analyzed. Results show that energy cost (C _e) is the most important component of C _T (50–72 % in the case studies). Thus, it is very important to adapt the design and management of the irrigation and pumping system throughout the irrigation season to the energy rate periods.