A Scoping Review of Remote Sensing-Based Surface Energy Balance (SEB) Evapotranspiration (ET) Modelling Approaches

This study presents a scoping review of remote sensing of ET using SEB approaches. Accurate determination of evapotranspiration (ET) is crucial for water resources management, water productivity estimations, yield modelling and understanding climate change impacts on ecosystems. Published articles that satisfied the search string, namely “Remote sensing” AND “Evapotranspiration” and “Surface energy balance” were searched on Scopus and Science Direct. Only articles published between 2014 and 2022, whose full text articles were available and in English, were considered. Articles were screened by reading their abstracts and a total of 24 articles were selected for this scaping review. This scoping review found that most studies were conducted in the USA (26%) and Brazil (13%). SEBAL was the most used approach followed by METRIC and SEBS. The frequency of use of SEBAL, METRIC and SEBS was 10, 8 and 7 respectively. Approximately 81% of the studies used Landsat imagery (Landsat 5, 7 and 8). All the studies used the Constant Evaporation Fraction for upscaling to daily, monthly, and seasonal scales. The most used validation techniques are the RMSE, R2 and correlation coefficient. We conclude that a standardization of the method for estimating ET using SEB methods should be considered for comparison purposes. Other upscaling techniques should be tested to see which is the most appropriate. A systematic review for the use of SEB approaches for ET estimating is advocated to uncover the state of knowledge on SEB techniques.