Application of the Irrigation Land Environmental Evaluation Tool for flood irrigation management and evaluation of water use

Irrigated zones worldwide suffer from water deficits, making it necessary to analyze irrigation management and to study alternatives to maximize adequate partitioning and distribution of irrigation water. The objective of this study is to compare the water use efficiency before (2001) and after (2002-2008) implementation of a new irrigation management plan in an area operating with traditional methods. To this end, annual water balances were carried out in a pilot basin (95 ha) in Northeast Spain during the period between 2001 and 2008. From these, the evolution of irrigation quality (Net Hydric Needs, Irrigation Efficiency, and Water Deficit) was analyzed in climatically different years and after changes in irrigation management (i. assignment of irrigation allowances, ii. on-demand flood irrigation system, and in. creation of water consumption accounts). The changes in irrigation management contributed to a better adjustment between water consumption and net hydric needs of crops, translating into improved irrigation efficiency and drainage reduction, although years with greater net hydric needs presented greater water deficits. Assignment of irrigation allowances and billing according to the volume of irrigation water consumed contributed to raising awareness of farmers about the value of water, especially in dry years. These facts, along with the flexibility in the time of irrigation granted by an "on-demand" management, led to an optimization of irrigation water applications to levels seldom exceeded by gravity irrigation in such permeable soils. (C) 2011 Elsevier B.V. All rights reserved.