Application Of The FAO-56 Approach To Calculate Evapotranspiration By Using Remote Sensing Data

Abstract

The growing demand of water resources around the world caused by global drought have severely reduced agricultural yield in semi-arid regions. So, to tackle this issue, remote sensing data can be utilized to determine the water needs of crops by assessing the crop coefficient (K_c) and actual evapotranspiration (ET_c). This research presents a methodology for determining K_c and reference evapotranspiration (ET₀) utilizing the FAO-56 method. Images of Landsat 8 satellite and meteorological data were employed to calculate ET_c, with ET₀ obtained via the Penman-Monteith equation. Additionally, vegetation indices, including the normalized difference vegetation index (NDVI) and the soil-adjusted vegetation index (SAVI). The results demonstrate a strong correlation between predicted and observed K_c values, validating the methodology's accuracy. The technique has considerable efficacy in high-resolution satellite imaging and signifies a crucial advancement in precision agriculture for arid and semi-arid areas.