Comparative analysis of the CROPWAT ET0 and MODIS PET for sustainable agricultural water resource management in Meghalaya, India

The current study uses the CROPWAT model and MODIS satellite data for assessing reference evapotranspiration (ET0) for five monitoring stations in Meghalaya from 2001 to 2022 and compares the results for sustainable agricultural water resource management in Meghalaya, one of the northeastern states of India. The analysis showed promising outcomes, with R2 ranging from 0.77 to 0.82, RMSE from 2.59 to 3.74, MAE from 1.83 to 2.95, and NSE from 0.72 to 0.78, with a minimum percent error of 1.43% and a maximum percent error of 2.91% as compared with the CROPWAT estimated ET0. To estimate the CWR of rice and maize, the FAO-CROPWAT model was used. Seasonal minimum and maximum crop water requirement (CWR) for rice and maize crops were found to be 462.5–652.2 mm and 314.6–455.8 mm, respectively. Additionally, the irrigation requirement (IR) for rice crop ranged from 152.9 to 378.8 mm, while for maize, it ranged from 0 to 30.2 mm in the study area. The study revealed that MODIS PET could be a valuable alternative for estimating CWRs and supporting water resource management strategies, particularly in areas lacking meteorological data.