Estimation of reference evapotranspiration using cropwat- 8 model in semi-arid region

Accurate estimation of crop reference evapotranspiration (ETo) in semi arid region is essential for better irrigation management and irrigation scheduling of crops. The main objective of this study is to estimates the crop reference evapotranspiration (ET) using climatic parameters. The FAO Penman-Monteith method is regarded as a standard and reliable technique to estimate ET and to evaluate other empirical methods. The ET₀ of Rangareddy district of Telangana state was estimated using the CROPWAT-8.0 model. CROPWAT-8 model indicated the total reference evapotranspiration estimated to be 1879.3 mm year⁻¹. The average annual ET₀in Rangareddy region is 5.15 mm day⁻¹. The highest monthly ET₀ value of 8.09 mm day⁻¹ was observed in May due to a higher temperature and sunshine hour. The lowest monthly ET₀value of 3.26 mm day⁻¹ was observed in December due to a lower temperature and sunshine hour.