Estimation of Seasonal Crop Water Demands for the Command Area of Eastern Sone High Level Canal (ESHLC) Irrigation Project, Bihar, Using the Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) Model

The performance assessment of Eastern Sone High Level Canal Command (ESHLC) was made through a case study of an experimental minor irrigation canal command in Bhagwatipur distributary in Jehanabad and Aurangabad, district of Bihar state of India, using RS-based techniques. This study confirmed that while there was a water source in the command, the farmers must also seriously think on harvesting the rainwater at the time of availability for its future use in agriculture. Later on employing the RS data the METRIC model-based ETa estimates using EEFlux-ETa data was validated with field-based observations in a canal command in Aurangabad district of Bihar and performance of the minor was assessed. METRIC-based ETa is a satellite-based image-processing model estimate that calculates actual evapotranspiration (ETa) as a residual of the surface energy balance. The daily ETa as estimated by the EEflux model was 1.5 mm/day in the early stage of crop growth (6th January 2020), 2.4 mm/day in the vegetative growth stage (7th February 2020), 4.9 mm/day in the full maturity stage (18th March 2020) and 3.49 mm/day (11th April 2020). The ETa values calculated using the EEFlux model were compared with crop water requirement calculated using the CROPWAT 8.0 model. The value of coefficient of determination (R2) was found to be 0.918. This shows that the METRIC-based EEFlux data is a good estimator of actual ET estimation of the crop, which can be used for the irrigation planning for the command area. Based on the present study appropriate water management strategies for balancing demand and supply gap after canal performance assessment were developed.