Reference crop evapotranspiration over India: A comparison of estimates from open pan with Penman-Monteith method

Abstract

In the present study the daily reference crop evapotranspiration (ET0) estimated from open pan evaporation data for 52 widely distributed locations across India are compared with P-M estimated ET0. The annual and intra-seasonal variability of ET0 and the inter comparison of these two methodologies has been carried out. Results showed that estimates of ET0 from open pan were always lower than those of P-M and error range was d” 29% across locations. Calibration coefficients evolved from the present study were found to reduce the errors considerably in ETo estimates.

Keywords

• Reference crop ET
• Penman-Monteith
• open pan evaporation
• calibration coefficients