Daily actual evapotranspiration estimation of different land use types based on SEBAL model in the agro-pastoral ecotone of northwest China.

Liangyan Yang,Jinbao Liu,Yuanyuan Yang,Zenghui Sun,Jianfeng Li,Tong Li,Débora Regina Roberti

doi:10.1371/journal.pone.0265138

Liangyan Yang, Jinbao Liu + Show 5 more

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https://doi.org/10.1371/journal.pone.0265138

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Journal: PloS one	Publication Date: Mar 15, 2022
Citations: 5	License type: CC BY 4.0

Affiliation: Xi'an University of Technology, Chang'an University

Abstract

Evapotranspiration (ET) plays a crucial role in hydrological and energy cycles, as well as in the assessments of water resources and irrigation demands. On a regional scale, particularly in the agro-pastoral ecotone, clarification of the distribution of surface ET and its influencing factors is critical for the rational use of water resources, restoration of the ecological environment, and protection of ecological water sources. The SEBAL model was used to invert the regional ET based on Landsat8 images in the agro-pastoral ecotone of northwest China. The results were indirectly verified by monitoring data from meteorological stations. The correlation between ET and surface parameters was analyzed. Thus, the main factors that affect the surface ET were identified. The results show that the SEBAL model determines an accurate inversion, with a correlation coefficient of 0.81 and an average root mean square error of 0.9 mm/d, which is highly suitable for research on water resources. The correlation coefficients of normalized vegetation index, surface temperature, land surface albedo, net radiation flux with daily ET were 0.5830, 0.8425, 0.3428 and 0.9111, respectively. The normalized vegetation index and the net radiation flux positively correlated with the daily ET, while the surface temperature and land surface albedo negatively correlated with the daily ET. The correlation from strong to weak is the net radiation flux > surface temperature > normalized vegetation index > surface albedo. In terms of spatial distribution, the daily ET of water was the highest, followed by woodland, wetland, cropland, built-up land, shrub land, grassland and bare land. However, the SEBAL model overestimates the inversion of daily ET of built-up land.

Highlights

IntroductionEvapotranspiration (ET) is an important part of the global water cycle [1]
The study of surface ET is highly important scientifically to ensure the rational use of water resources and the protection of ecosystems in the study area [14,15]
Liu and Hu investigated the effects of land use/cover change and climate change on wetland ET using surface energy balance algorithm for land (SEBAL), and the results showed that the average relative error of regional ET estimated by the SEBAL model was 9.01% [23]

Summary

Introduction

Evapotranspiration (ET) is an important part of the global water cycle [1]. It is the channel that transforms surface and atmospheric water, which directly affects the spatial distribution of global precipitation and vegetation [2,3]. Studies have shown that > 60% of the precipitation that reaches the surface through condensation returns to the atmosphere through the process of ET, and this proportion can be as high as 90% owing to a reduction in precipitation and a higher ET in arid areas [4–6]. The surface ET plays an important role in the global water and energy cycles [7]. The study of surface ET is highly important scientifically to ensure the rational use of water resources and the protection of ecosystems in the study area [14,15]

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