SEBAL Model with Remotely Sensed Data to Improve Water-Resources Management under Actual Field Conditions

TLDR

Water management is shifting from supply augmentation to consumption limitation, and spatio‑temporal evapotranspiration data from satellite‑based energy balance models help link land use, allocation, and use. The study aims to describe SEBAL’s principles, assess its accuracy across climatic conditions at field and catchment scales, and demonstrate its application in a Yakima River basin case study for water‑conservation evaluation. SEBAL is an energy‑balance algorithm that estimates evapotranspiration from satellite imagery, and its accuracy was evaluated under various soil wetness and plant community conditions at both field and watershed scales. SEBAL achieved 85–95 % accuracy at field scale and 96 % for annual watershed ET, has been applied in over 30 countries, and the Yakima River case study shows remote‑sensing ET can evaluate water‑conservation projects.

Abstract

Water management emphasis tends to shift from supply augmentation to limiting water consumption. Spatio-temporal information on actual evapotranspiration (ET) helps users to better understand evaporative depletion and to establish links between land use, water allocation, and water use. Satellite-based measurements, used in association with energy balance models, can provide the spatial distribution of ET for these linkages. This paper describes the major principles of the Surface Energy Balance Algorithm for Land (SEBAL) and summarizes its accuracy under several climatic conditions at both field and catchment scales. For a range of soil wetness and plant community conditions, the typical accuracy at field scale is 85% for 1day and it increases to 95% on a seasonal basis. The accuracy of annual ET of large watersheds was found to be 96% on average. SEBAL has been applied in more than 30 countries worldwide, and the 26 research studies that were conducted over the past 10years are now gradually being replaced by application studies (17 studies finished). A short case study in the Yakima River basin (Washington State) is presented as new material to demonstrate how ET from remote sensing can be used for evaluating water conservation projects.