Inter-Relationship between Reference Evapotranspiration and Meteorological Factors at Tarai Region of Uttarakhand, India

In this study, impact of different meteorological parameters and their inter-relationship with reference evapotranspiration (ET o ) calculated by FAO-Penman Monteith (FAO-PM) equation for Udham Singh Nagar district situated in Tarairegion of Uttarakhand wereanalyzed on the basis of 22 years (1991-2012) of daily meteorological data recorded at GB. Pant University of Agriculture and Technology, Pantnagar. For conducting analysis, daily values of observed meteorological parameterswere considered as independent variables, whereas, FAO-PM ETo values were taken as dependent variable.Dailyvalues of observed meteorological parameters and EToweregrouped together to get their respective values for all 52 SMWs and 12 months in accordance with CWS-1 format suggested by IMD, Pune with aim to identify climatic variables which can predict ETofairly accurately on weekly and monthly basis and it was found that best performance indicators for predicting ET o are pan evaporation followed by sunshine duration and maximum air temperature. It was also found that on both weekly and monthly basis, ETocan be fairly accurately predicted by developed equationsat Tarairegion of Uttarakhand, India.