Remote sensing to estimate ET-fluxes and the performance of an irrigation district in southern Italy Simona Consoli a, * , Guido D’Urso b , Attilio Toscano a a Department of Agricultural Engineering, University of Catania, Via S. Sofia 100, 95123 Catania, Italy b Department of Agricultural Engineering, University of Naples ‘‘Federico II’’, Via Universita ` 100, 80055 Portici (Napoli), Italy Accepted 25 April 2005 Available online 23 May 2005 Abstract Satellite remote sensed data on canopy biophysical properties, ground data and agro-meteorological information were combined to estimate evapotranspiration (ET) fluxes of orange orchards using a modified Penman–Monteith equation. The study was carried out during the irrigation season 2004 in an irrigation district, cover for about 95% with orange groves, of 1550 ha located in eastern Sicily (Italy). The spatial pattern in ET-fluxes have been analysed using IKONOS high-resolution satellite and hyper- spectral ground data acquired and processed for the study-area. The remote estimates of ET-fluxes varied between 1.3 and 5.7 mm/day, with a daily average value of about 4.2 mm, showing a good agreement with crop ET values determined as residual of soil water balance of selected ground control sites. Crop coefficient estimates ranged between 0.22 and 1.08 showing positive correlations with percentages of ground cover (C g ) increasing from 30 to 80% ground shading and with LAI values. By comparing ET estimates with water volumes supplied in each sub-district of the study-area, the performance indicator ‘‘IP’’ was evaluated, allowing to rank the conditions of un-fulfilment of crop water requirements by public and private water distribution systems. Generally, out of 29 sub-districts, 14 had ‘‘IP’’ values less than 50%, revealing a sub-optimal water supply for the study-area. # 2005 Elsevier B.V. All rights reserved. Keywords: Crop water requirements; Irrigation water management; Remote sensing www.elsevier.com/locate/agwat Agricultural Water Management 81 (2006) 295–314 * Corresponding author. Tel.: +39 095 7147547; fax: +39 095 7147600. E-mail address: simona.consoli@unict.it (S. Consoli). 0378-3774/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.agwat.2005.04.008