{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T15:38:04Z","timestamp":1775057884091,"version":"3.50.1"},"reference-count":58,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2013,8,5]],"date-time":"2013-08-05T00:00:00Z","timestamp":1375660800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa) based on the Enhanced Vegetation Index (EVI) from the Moderate Resolution Imaging Spectrometer (MODIS) sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo). The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 \u2212 e\u2212bEVI) \u2212 c], where the term (1 \u2212 e\u2212bEVI) is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73). It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89) difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.<\/jats:p>","DOI":"10.3390\/rs5083849","type":"journal-article","created":{"date-parts":[[2013,8,5]],"date-time":"2013-08-05T12:16:02Z","timestamp":1375704962000},"page":"3849-3871","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":99,"title":["Estimating Riparian and Agricultural Actual Evapotranspiration by Reference Evapotranspiration and MODIS Enhanced Vegetation Index"],"prefix":"10.3390","volume":"5","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0674-103X","authenticated-orcid":false,"given":"Pamela","family":"Nagler","sequence":"first","affiliation":[{"name":"Sonoran Desert Research Station, Southwest Biological Science Center, US Geological Survey, 1110 E. South Campus Drive, Room 123, Tucson, AZ 85721, USA"},{"name":"CSIRO Land and Water, Waite Road, Gate 4, Glen Osmund, SA 5064, Australia"}]},{"given":"Edward","family":"Glenn","sequence":"additional","affiliation":[{"name":"CSIRO Land and Water, Waite Road, Gate 4, Glen Osmund, SA 5064, Australia"}]},{"given":"Uyen","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Environmental Research Laboratory, University of Arizona, 2601 E. Airport Dr., Tucson, AZ 85706, USA"}]},{"given":"Russell","family":"Scott","sequence":"additional","affiliation":[{"name":"USDA-Agricultural Research Service, 2000 E. Allen Rd., Tucson, AZ 85719, USA"}]},{"given":"Tanya","family":"Doody","sequence":"additional","affiliation":[{"name":"CSIRO Land and Water, Waite Road, Gate 4, Glen Osmund, SA 5064, Australia"}]}],"member":"1968","published-online":{"date-parts":[[2013,8,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"769","DOI":"10.2307\/1313099","article-title":"The natural flow regime","volume":"47","author":"Poff","year":"1997","journal-title":"BioScience"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"211","DOI":"10.3390\/rs2010211","article-title":"A holistic view of global croplands and their water use for ensuring global food security in the 21st Century through advanced remote sensing and non-remote sensing approaches","volume":"2","author":"Thenkabail","year":"2010","journal-title":"Remote Sens"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1061\/(ASCE)0733-9437(2005)131:1(24)","article-title":"Prediction accuracy for project-wide evapotranspiration using crop coefficients and reference evapotranspiration","volume":"131","author":"Allen","year":"2005","journal-title":"J. Irrig. Drain. Eng"},{"key":"ref_4","first-page":"1107","article-title":"Mapping and monitoring agricultural crops and other land cover in the Lower Colorado River Basin","volume":"64","author":"Congalton","year":"1998","journal-title":"Photogram. Eng. Remote Sensing"},{"key":"ref_5","unstructured":"Allen, R., Pereira, L., Rais, D., Smith, M., Solomon, K., and O\u2019Halloran, T. (1998). Crop Evapotranspiration\u2014Guidelines for Computing Crop Water Requirements, Food and Agriculture Organization of the United Nations. FAO Irrigation and Drainage Paper 56."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1080\/07352680701402503","article-title":"Integrating remote sensing and ground methods to estimate evapotranspiration","volume":"26","author":"Glenn","year":"2007","journal-title":"Crit. Rev. Plant Sci"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1007\/s10712-008-9037-z","article-title":"Estimating land surface evaporation: A review of methods using remotely sensed surface temperature data","volume":"29","author":"Kalma","year":"2008","journal-title":"Surv. Geophys"},{"key":"ref_8","first-page":"95","article-title":"Development of reflectance-based crop coefficients for corn","volume":"22","author":"Neale","year":"1989","journal-title":"Irrig. Sci"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2017","DOI":"10.13031\/2013.24105","article-title":"Wheat irrigation management using multispectral crop coefficients. I. Crop evapotranspiration prediction","volume":"50","author":"Hunsaker","year":"2007","journal-title":"Trans. ASABE"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4050","DOI":"10.1002\/hyp.8392","article-title":"Vegetation index-based crop coefficients to estimate evapotranspiration by remote sensing in agricultural and natural ecosystems","volume":"25","author":"Glenn","year":"2011","journal-title":"Hydrol. Process"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0034-4257(94)90090-6","article-title":"Relations between evaporation coefficients and vegetation indices studies by model simulations","volume":"50","author":"Choudhury","year":"1994","journal-title":"Remote Sens. Environ"},{"key":"ref_12","first-page":"490","article-title":"Evapotranspiration by remote sensing","volume":"32","author":"Tang","year":"2010","journal-title":"Surv. Geophys"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.rse.2011.08.025","article-title":"Use of Landsat thermal imagery in monitoring evapotranspiration and managing water resources","volume":"122","author":"Anderson","year":"2012","journal-title":"Remote Sens. Environ"},{"key":"ref_14","first-page":"2082","article-title":"A comparison of operational remote-sensing based models for estimating crop evapotranspiration","volume":"49","author":"Neale","year":"2009","journal-title":"Agric. For. Meteorol"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.agwat.2013.03.024","article-title":"Monitoring evapotranspiration of irrigated crops using crop coefficients derived from time series of satellite images. II. Application on basin scale","volume":"125","author":"Escuin","year":"2013","journal-title":"Agric. Water Manage"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"146","DOI":"10.1016\/j.jhydrol.2007.07.002","article-title":"Annual groundwater evapotranspiration mapped from single satellite scenes","volume":"344","author":"Groeneveld","year":"2007","journal-title":"J. Hydrol"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1002\/eco.35","article-title":"Wide-area estimates of saltcedar (Tamarix spp.) evapotranspiration on the lower Colorado River measured by heat balance and remote sensing methods","volume":"2","author":"Nagler","year":"2009","journal-title":"Ecohydrology"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1273","DOI":"10.3390\/rs1041273","article-title":"An empirical algorithm for estimating agricultural and riparian evapotranspiration using MODIS Enhanced Vegetation Index and ground measurements of ET. I. Description of method","volume":"1","author":"Nagler","year":"2009","journal-title":"Remote Sens"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/S0022-1694(99)00194-8","article-title":"Using the FAO-56 dual crop coefficient method over an irrigated region as part of an evapotranspiration intercomparison study","volume":"229","author":"Allen","year":"2000","journal-title":"J. Hydrol"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/0034-4257(92)90102-P","article-title":"Canopy reflectance, photosynthesis, and transpiration. III. A reanalysis using improved leaf models and a new canopy integration scheme","volume":"42","author":"Seller","year":"1992","journal-title":"Remote Sens. Environ"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"439","DOI":"10.3390\/rs4020439","article-title":"Satellite NDVI assisted monitoring of vegetable crop evapotranspiration in California\u2019s San Joaquin Valley","volume":"4","author":"Johnson","year":"2012","journal-title":"Remote Sens"},{"key":"ref_22","unstructured":"Melton, F. Available online: http:\/\/ecocast.arc.nasa.gov\/sims\/."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/j.agwat.2011.10.004","article-title":"Long-term water balances in La Violada irrigation district (Spain): I. Sequential assessment and minimization of closing errors","volume":"102","author":"Barros","year":"2011","journal-title":"Agric. Water Manage"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1569","DOI":"10.1016\/j.agwat.2011.04.014","article-title":"Long-term water balances in La Violada Irrigation District (Spain): II. Analysis of irrigation performance","volume":"98","author":"Barros","year":"2011","journal-title":"Agric. Water Manage"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/j.rse.2005.05.011","article-title":"Evapotranspiration on western US rivers estimated using the Enhanced Vegetation Index from MODIS and data from eddy covariance and Bowen ratio flux towers","volume":"97","author":"Nagler","year":"2005","journal-title":"Remote Sens. Environ"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1232","DOI":"10.1016\/j.jaridenv.2008.01.001","article-title":"Multiyear riparian evapotranspiration and groundwater use for a semiarid watershed","volume":"72","author":"Scott","year":"2008","journal-title":"J. Arid Environ"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3265","DOI":"10.1029\/94WR02274","article-title":"Groundwater discharge by phreatophyte shrubs in the Great Basin as related to depth to groundwater","volume":"30","author":"Nichols","year":"1994","journal-title":"Water Resour. Res"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1007\/s00442-009-1455-1","article-title":"Patterns of Tamarix water use during a record drought","volume":"162","author":"Nippert","year":"2010","journal-title":"Oecologia"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1016\/j.jaridenv.2004.09.025","article-title":"Comparative ecophysiology of Tamarix ramosissima and native trees in western US riparian zones","volume":"61","author":"Glenn","year":"2005","journal-title":"J. Arid Environ"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1046\/j.1365-3040.1998.00287.x","article-title":"Limitation of plant water use by rhizosphere and xylem conductance: Results from a model","volume":"21","author":"Sperry","year":"1998","journal-title":"Plant Cell Environ"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.jhydrol.2009.02.013","article-title":"Scaling of potential evapotranspiration with MODIS data reproduces flux observations and catchment water balance observations across Australia","volume":"369","author":"Guerschman","year":"2009","journal-title":"J. Hydrol"},{"key":"ref_32","first-page":"103","article-title":"Leaf area index and Normalized Difference Vegetation Index as predictors of canopy characteristics and light interception by riparian species on the Lower Colorado River","volume":"116","author":"Nagler","year":"2004","journal-title":"Agric. For. Meteorol"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1016\/j.agrformet.2012.09.003","article-title":"Two separate periods of the LAI-Vis relationships using in situ measurements in a deciduous broadleaf forest","volume":"169","author":"Potithep","year":"2013","journal-title":"Agric. For. Meteorol"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.agrformet.2003.09.001","article-title":"Interannual and seasonal variation in fluxes of water and carbon dioxide from a riparian woodland ecosystem","volume":"122","author":"Scott","year":"2004","journal-title":"Agric. For. Meteorol"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1111\/j.1365-2486.2005.01093.x","article-title":"Ecohydrological impacts of woody-plant encrhoachment: Seasonal patterns of water and carbon dioxide exchange within a semiarid riparian environment","volume":"12","author":"Scott","year":"2006","journal-title":"Glob. Change Biol"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1016\/S0168-1923(02)00109-0","article-title":"Energy balance closure at FLUXNET sites","volume":"113","author":"Wilson","year":"2002","journal-title":"Agric. For. Meteorol"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1016\/S0168-1923(00)00123-4","article-title":"Correcting eddy-covariance flux underestimates at a grassland site","volume":"103","author":"Twine","year":"2000","journal-title":"Agric. For. Meteorol"},{"key":"ref_38","unstructured":"Chatterjee, S. (2010). Estimating Evapotranspiration Using Remote Sensing: A Hybrid Approach between MODIS Derived Enhanced Vegetation Index, Bowen Ratio System, and Ground-based Micrometeorological Data, Wright State University. Ph.D. Dissertation."},{"key":"ref_39","unstructured":"Available online: http:\/\/ag.arizona.edu\/azmet\/."},{"key":"ref_40","unstructured":"Hanson, B., Orloff, S., Bali, K., Sanden, B., and Putnam, D. (2011, January 1\u20132). Evapotranspiration of Fully-Irrigated Alfalfa in Commercial Fields. Fresno, CA, USA. Available online: http:\/\/calasa.ucdavis.edu\/files\/73479.pdf#page=80."},{"key":"ref_41","unstructured":"California Irrigation Management System (CIMIS) State of California, 2013. Available online: http:\/\/wwwcimis.water.ca.gov\/cimis\/welcome.jsp."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.advwatres.2012.07.023","article-title":"Can weighing lysimeter ET represent surrounding field ET well enough to test flux station measurements of daily and sub-daily ET?","volume":"50","author":"Evett","year":"2012","journal-title":"Adv. Water. Resour"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"4132","DOI":"10.1002\/hyp.8371","article-title":"Water balance of irrigated areas: A remote sensing approach","volume":"25","author":"Taghvaeian","year":"2011","journal-title":"Hydrol. Process"},{"key":"ref_44","unstructured":"US Bureau of Reclamation (2002). Compilation of Records in Accordance with Article V of the Decree of the Supreme Court of the United States in Arizona v. California et al. Calendar Year 2001, US Bureau of Reclamation. Available online: http:\/\/www.usbr.gov\/lc\/region\/g4000\/4200Rpts\/DecreeRpt\/2001DecreeRpt.pdf."},{"key":"ref_45","unstructured":"Colorado River Board of California Available online: http:\/\/www.sci.sdsu.edu\/salton\/PotentialImpactsSaltonSea.html."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1071\/EA06094","article-title":"On-farm measurement of the water use and productivity of maize","volume":"48","author":"Greenwood","year":"2008","journal-title":"Austral. J. Exp. Agric"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1394","DOI":"10.1016\/j.agwat.2011.04.001","article-title":"Irrigation evaluation based on performance analysis at the Bear River Irrigation Project (U.S.A.)","volume":"98","author":"Lecina","year":"2011","journal-title":"Agric. Water Manage"},{"key":"ref_48","first-page":"177","article-title":"Evapotranspiration crop coefficients for mixed riparian plant community and transpiration crop coefficients for Common reed, Cottonwood and Peach-leaf willow in the Platte River Basin, Nebraska U.S.A","volume":"481","author":"Imrak","year":"2012","journal-title":"J. Hydrol"},{"key":"ref_49","unstructured":"Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) Available online: http:\/\/daac.ornl.gov\/MODIS\/modis.html."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"901","DOI":"10.1016\/j.rse.2007.06.025","article-title":"Global estimates of the land-atmosphere water flux based on monthly AVHRR and ISLSCP-II data, validated at 16 FLUXNET sites","volume":"112","author":"Fisher","year":"2008","journal-title":"Remote Sens. Environ"},{"key":"ref_51","unstructured":"Brown, P., and Kopec, D. Available online: http:\/\/ag.arizona.edu\/pubs\/water\/az1195.pdf."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"899","DOI":"10.1016\/j.agwat.2010.12.015","article-title":"Evapotranspiration information reporting: I. Factors governing measurement accuracy","volume":"98","author":"Allen","year":"2011","journal-title":"Agric. Water Manage"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.rse.2012.11.004","article-title":"Evaluation of optical remote sensing to estimate actual evapotranspiration and canopy conductance","volume":"129","author":"Yebra","year":"2013","journal-title":"Remote Sens. Environ"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"1781","DOI":"10.1016\/j.rse.2011.02.019","article-title":"Improvements to a MODIS global terrestrial evapotranspiration product","volume":"115","author":"Mu","year":"2011","journal-title":"Remote Sens. Environ"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/j.1466-8238.2010.00578.x","article-title":"ET come home: potential evapotranspiration in geographical ecology","volume":"20","author":"Fisher","year":"2011","journal-title":"Glob. Ecol. Biogeogr"},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Glenn, E.P., Monino, K., Nagler, P.L., and Hultine, K.R. (2013). Phreatophytes under stress: Transpiration and stomatal conductance of saltcedar (Tamarix spp.) in a high-salinity environment. Plant Soil.","DOI":"10.1007\/s11104-013-1803-0"},{"key":"ref_57","first-page":"394","article-title":"Satellite-based energy balance for mapping evapotranspiration with internalized calibration (METRC)\u2014Applications","volume":"138","author":"Allen","year":"2007","journal-title":"J. Irrig. Drain. Eng"},{"key":"ref_58","unstructured":"King, E.A., van Niel, T.G., van Djik, A., Wang, Z., Paget, M.J., Raupach, T., Guerschman, J., Haverd, V., McVicar, T.R., and Miltenberg, I. (2011). Actual Evapotranspiration Estimates for Australia. Intercomparison and Evaluation, CSIRO."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/5\/8\/3849\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:48:25Z","timestamp":1760219305000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/5\/8\/3849"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,8,5]]},"references-count":58,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2013,8]]}},"alternative-id":["rs5083849"],"URL":"https:\/\/doi.org\/10.3390\/rs5083849","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,8,5]]}}}