Vol.1, No 5, 1998 pp. 617-625
UDC 626.85(045)

---

COMPARISON OF PREDICTION MODELS
OF REFERENCE CROP EVAPOTRANSPIRATION
Slaviša Trajković
Faculty of Civil Engineering and Architecture, University of Niš
Beogradska 14, 18000 Niš, Yugoslavia

---

Abstract. The prediction of evapotranspiration is necessary for a reliable management of irrigation systems. This paper is based on several models used for the prediction of reference crop evapotranspiration in the area of Niš, Yugoslavia. Two simple mathematical models (Yearly Differencing model and Monthly AVerage model), in which prediction is based on appropriate previous values of reference crop evapotranspiration, are present here. A seasonal ARIMA (AutoRegressive Integrated Moving Average) model is identified and compared to the previous models. Based on the results of model comparisons it is concluded that seasonal ARIMA can provide a reasonably accurate prediction of reference crop evapotranspiration. The obtained results show that the seasonal ARIMA model is a very effective and reliable prediction model.
Key words: Prediction, Evapotranspiration, ARIMA model.

---

UPOREDJIVANJE MODELA PREDIKCIJE
REFERENTNE EVAPOTRANSPIRACIJE Pouzdano upravljanje irigacionim sistemima se ne može zamisliti bez predikcije evapotranspiracije. U radu se vrši uporedjivanje nekoliko modela predikcije referentne evapotranspiracije. Dva jednostavna matematička modela kod kojih se predikcija zasniva na odgovarajućim prethodnim vrednostima su prikazana u ovom radu. Sezonski ARIMA model je identifikovan i uporedjen sa prethodnim modelima. Na osnovu rezultata uporedjivanja može se zaključiti da sezonski ARIMA model može obezbediti najpouzdaniju predikciju referentne evapotranspiracije.
Ključne reči: Predikcija, Evapotranspiracija, ARIMA model