Vol.9, No 2, 2011 pp. 335 - 345
UDC 551.573:551.58=111
DOI: 10.2298/FUACE1102335T


MINIMUM WEATHER DATA REQUIREMENTS FOR ESTIMATING REFERENCE EVAPOTRANSPIRATION
Slaviša Trajković1*, Vladimir Stojnić2, Milan Gocić1
1Faculty of Civil Engineering and Architecture, University of Niš
2LinkWater O&M Alliance, 200 Creek St, Spring Hill, Queensland, Australia
E-mail: *slavisa.trajkovic@gaf.ni.ac.rs
The International Commission for Irrigation and Drainage (ICID) and Food and Agriculture Organisation of the United Nations (FAO) have proposed using the Penman-Monteith method as the standard method for estimating reference evapotranspiration (ET0), and for evaluating other methods. The FAO-56 Penman-Monteith (FAO-56 PM) method requires the numerous weather data that are not available in the most of the stations. The objectives of this study were: first, to estimate errors that can arise if some weather data are not available and have to be estimated; second, to compare the FAO-56 PM ET0 values computed under various levels of data availability; and third, to determine minimum weather data requirements for estimating ET0 without decreasing the acceptable accuracy. For this study, full weather data sets were collected from six humid weather stations from Serbia (Southeast Europe).The main conclusion is that the minimum and maximum air temperature and "local default" value of wind speed are the minimum data requirements necessary to apply the FAO-56 PM method in humid climate.
Key words: Reference evapotranspiration, Penman-Monteith, Air temperature, Solar radiation, Relative humidity, Wind speed.

PRORAČUN REFERENTNE EVAPOTRANSPIRACIJE KORIŠĆENJEM MINIMALNOG BROJA KLIMATSKIH PODATAKA
ICID i FAO predlažu korišćenje Penman-Monteith metode kao standardne metode za proračun referentne evapotranspiracije (ET0). FAO-56 Penman-Monteith (FAO-56 PM) metoda zahteva brojne klimatske podatke koje nisu na raspolaganju na najvećem broju stanica. Osnovni cilj ovog rada je da se odredi monimalni skup klimatskih podataka koji su potrebni za pouzdani proračun referentne evapotranspiracije. Na osnovu istraživanja prikazanog u ovom radu zaključeno je da se taj skup sastoji od vrednosti minimalne i maksimalne temperature vazduha i od višegodišnje prosečnelokalne vrednosti brzine vetra.
Ključne reči: Referentna evapotranspiracija, Penman-Monteith, temperatura vazduha, solarna radijacija, vlažnost vazduha, brzina vetra