Modelling potential evapotranspiration: Statistical analysis for Madurai’s water dynamics

Abstract

Potential evapotranspiration is a comprehensive process encompassing both evaporation and transpiration that helps to determine the removal of water from both the soil and plant surfaces. It serves as a crucial mechanism for returning moisture to the atmosphere. The study specifically concentrates on computing the Weekly Potential Evapotranspiration (PET) for Madurai district. Models such as FAO Penman-Monteith, Modified Penman, Penman, Priestley Taylor, Blaney Criddle and Hargreaves models were compared in this study using Multiple Linear Regression. Performance of the fitted models were compared using accuracy metrics such as Root Mean Squared Error (RMSE), RAE, Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and the coefficient of determination (R2). The Penman model emerged as the most pertinent model, exhibiting the least bias and the highest R2.