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Irrig Sci (2010) 28:461477 DOI 10.1007/s00271-010-0207-7
ORIGINAL PAPER
Performance assessment of an irrigation scheme using indicators determined with remote sensing techniques
C. Santos Ignacio J. Lorite M. Tasumi
R. G. Allen E. Fereres
Received: 2 June 2009 / Accepted: 12 January 2010 / Published online: 4 February 2010 Springer-Verlag 2010
Abstract In this work, remote sensing-based assessments of actual evapotranspiration using METRIC integrated with a water balance model provided accurate estimates of irrigation performance. This new methodology was applied and tested in the GenilCabra Irrigation Scheme located in southern Spain during the 20042005 irrigation season. The performance indicators used, the annual relative irrigation supply (ARIS) and the irrigation water productivity (IWP), required ET input data which were calculated using either METRIC or standard FAO methodology. The new procedure that used METRIC detected overirrigation (ARIS of 1.27) in situations where the ARIS calculated with the standard FAO methodology indicated near-optimal irrigation (ARIS of 0.98). Additionally, the proposed methodology allows the estimation of the volume of applied water at the eld scale. Comparisons between the ARIS and IWP values obtained from actual applied water records against those calculated with the new methodology resulted in good agreement. It is concluded that the integration of the METRIC method to calculate actual ET with
a water balance model allowed the determination of performance indicators in an irrigation scheme in a reliable and accurate fashion, requiring only very limited information at the eld level.
Introduction
The availability of water for irrigation will probably decrease in the future due to increased demands from other sectors such as municipal, tourism, recreation, and the environment. In Spain, fresh water demand is around 35,000 hm3/year, with about 70% devoted to irrigation, and the rest to other uses (MIMAM 1998). In this scenario, assessments of irrigation performance for improving water management in irrigated areas are of high importance. These activities are needed not only to improve water productivity (Hsiao et al. 2007) but also to increase the sustainability of irrigated agriculture.
The improvement in water management in an irrigation scheme requires the assessment of irrigation performance as a point of departure. Robust models for calculating consumptive use requirements now exist (Doorenbos and Pruit 1977; Allen et al. 1998). Additionally, to facilitate data acquisition and to carry...