A modified temperature based model for estimation of potential evapotranspiration over Ghataprabha river basin, south India

다국어 초록 (Multilingual Abstract)

Potential Evapotranspiration (PET) is one of the significant hydrological parameters, but complicated to estimate due to various meteorological parameters involved. Accurate estimation of PET at spatial scale is a major requirement for arid and semiarid agriculture regions such as Ghatapraha river basin for study of water balance. Temperature based models have emerged as promising tools in extracting the spatial distribution of the PET, using remote sensed images. The main objective of the study is, to develop a site-specific temperature-based model for estimation of PET in semiarid regions, applicable to Ghataprabha basin. Performance of five different temperature-based PET models were evaluated by comparing with the standard Penman-Monteith equation for the year 2013 and 2014. The Hargreaves-Samani equation performed better with statistical parameters RMSE, MBE, MPE and R2 of 0.65, 0.43, 10.64 and 0.81 respectively. The model was further calibrated and site-specific modified Hargreaves-Samani equation was developed. The results revealed that spatial PET estimated by modified method based on satellite-derived spatial air temperature data performed better in spatial scale. The proposed approach is new and is advantageous as the spatial distribution of PET can be obtained, with limited data of temperature, where unavailability of the spatial climate data is a major concern.