Assessment of Evapotranspiration Remote Sensing Products in the Heihe River Basin Based on Station Fluxes Dataset 

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  • 1. School of Environment and Resources of Shanxi University / Shanxi Yellow River LaboratoryTaiyuan 030006ShanxiChina
    2. Northwest Institute of Ecological Environment and ResourcesChinese Academy of Sciences / National Key Laboratory for Ecological Security and Sustainable Development in Arid Areas / Alxa Desert Eco-Hydrology Experimental Research StationLanzhou 730000GansuChina

Online published: 2025-04-29

Abstract

Evapotranspiration is an important part of the energy balance of terrestrial ecosystems and a key link in the atmospheric water cycle. Howeverdue to the limitation of practical conditionsthere is a lack of evaluation of the performance and applicability of long-time remote sensing evapotranspiration products of different underlying surface types at the basin scaleresulting in many uncertainties in the estimation of water demand of the basin ecosystemthe evaluation of water resourcesand the management and use of water resources. Thereforebased on the long-term time-series flux monitoring data of the ground positioning stations of different ecosystems in the Heihe River Basinthis paper uses the random forest algorithm to construct a multi-sitelong-time serieshigh-precision ground actual evapotranspiration dataset15 stations113 station yearsdaily scale),and selects six commonly used remote sensing evapotranspiration products SSEBopGLEAMMOD16PML_V2GLASS and ETMonitorand extracted the annual values of evapotranspiration products of raster pixels in each ecosystem type siteand evaluated the accuracy and applicability of each remote sensing evapotranspiration prod‐ uct in the Heihe River Basin by R²RMSEMAEBias and other indicators. The results showed that:(1SSE‐ Bop products had the highest overall accuracy in the Heihe River BasinR²=0. 63RMSE=251. 99 mm·a-1),followed by ETMonitor productsR²=0. 26RMSE=275. 47 mm·a-1),GLEAM productsR² was not significant), GLASS products with the smallest Bias were -22. 57 mmand GLEAM products were the largest-317. 49 mm.2The performance of the six remote sensing evapotranspiration products in mountain forest system and cropland system was relatively goodand the performance in desert forest system and desert system was the worstwhile the actual evapotranspiration of wetland system was generally underestimated. Among themthe SSEBop product was underestimated in all ecological types except the cropland systemwhile the GLASS product performed well in the desert forest system but seriously overestimated the actual evapotranspiration of the desert system.3At the station scalethe ET of wetland ecosystem was the largestabout 1210 mmand that of desert ecosystem was the smallestabout 180 mm. By evaluating the accuracy and applicability of different re‐ mote sensing evapotranspiration products in the Heihe River Basinthis study provides a scientific basis for the selection of evapotranspiration models in the basin under complex terrainclimate and ecosystem conditions in arid areasand also provides a reference for the scientific management and use of water resources and ecological protection in the basin.

Cite this article

WU Bo, GAO Guanlong, YU Tengfei, HAN Tuo, WANG Qixiang . Assessment of Evapotranspiration Remote Sensing Products in the Heihe River Basin Based on Station Fluxes Dataset [J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00030

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