Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in China

Continuous evapotranspiration (ET) data with high spatial resolution are crucial for water resources management in irrigated agricultural areas in arid regions. Many global ET products are available now but with a coarse spatial resolution. Spatial-temporal fusion methods, such as the spatial and te...

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Main Authors: Jingjing Sun, Wen Wang, Xiaogang Wang, Luca Brocca
Format: Article
Language:English
Published: MDPI AG 2023-11-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/15/22/5411
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author Jingjing Sun
Wen Wang
Xiaogang Wang
Luca Brocca
author_facet Jingjing Sun
Wen Wang
Xiaogang Wang
Luca Brocca
author_sort Jingjing Sun
collection DOAJ
description Continuous evapotranspiration (ET) data with high spatial resolution are crucial for water resources management in irrigated agricultural areas in arid regions. Many global ET products are available now but with a coarse spatial resolution. Spatial-temporal fusion methods, such as the spatial and temporal adaptive reflectance fusion model (STARFM), can help to downscale coarse spatial resolution ET products. In this paper, the STARFM model is improved by incorporating the temperature vegetation dryness index (TVDI) into the data fusion process, and we propose a spatial and temporal adaptive evapotranspiration downscaling method (STAEDM). The modified method STAEDM was applied to the 1 km SSEBOP ET product to derive a downscaled 30 m ET for irrigated agricultural fields of Northwest China. The STAEDM exhibits a significant improvement compared to the original STARFM method for downscaling SSEBOP ET on Landsat-unavailable dates, with an increase in the squared correlation coefficients (r<sup>2</sup>) from 0.68 to 0.77 and a decrease in the root mean square error (RMSE) from 10.28 mm/10 d to 8.48 mm/10 d. The ET based on the STAEDM additionally preserves more spatial details than STARFM for heterogeneous agricultural fields and can better capture the ET seasonal dynamics. The STAEDM ET can better capture the temporal variation of 10-day ET during the whole crop growing season than SSEBOP.
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spelling doaj.art-e16c3e10cbca496d8f5128352a057a962023-11-24T15:04:48ZengMDPI AGRemote Sensing2072-42922023-11-011522541110.3390/rs15225411Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in ChinaJingjing Sun0Wen Wang1Xiaogang Wang2Luca Brocca3State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, ChinaState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, ChinaThe Pearl River Water Resources Research Institute, Guangzhou 510611, ChinaResearch Institute for the Geo-Hydrological Protection, National Research Council (CNR), Via Madonna Alta 126, 06128 Perugia, ItalyContinuous evapotranspiration (ET) data with high spatial resolution are crucial for water resources management in irrigated agricultural areas in arid regions. Many global ET products are available now but with a coarse spatial resolution. Spatial-temporal fusion methods, such as the spatial and temporal adaptive reflectance fusion model (STARFM), can help to downscale coarse spatial resolution ET products. In this paper, the STARFM model is improved by incorporating the temperature vegetation dryness index (TVDI) into the data fusion process, and we propose a spatial and temporal adaptive evapotranspiration downscaling method (STAEDM). The modified method STAEDM was applied to the 1 km SSEBOP ET product to derive a downscaled 30 m ET for irrigated agricultural fields of Northwest China. The STAEDM exhibits a significant improvement compared to the original STARFM method for downscaling SSEBOP ET on Landsat-unavailable dates, with an increase in the squared correlation coefficients (r<sup>2</sup>) from 0.68 to 0.77 and a decrease in the root mean square error (RMSE) from 10.28 mm/10 d to 8.48 mm/10 d. The ET based on the STAEDM additionally preserves more spatial details than STARFM for heterogeneous agricultural fields and can better capture the ET seasonal dynamics. The STAEDM ET can better capture the temporal variation of 10-day ET during the whole crop growing season than SSEBOP.https://www.mdpi.com/2072-4292/15/22/5411evapotranspirationdata fusionSTARFMdownscalingTVDISSEBOP
spellingShingle Jingjing Sun
Wen Wang
Xiaogang Wang
Luca Brocca
Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in China
Remote Sensing
evapotranspiration
data fusion
STARFM
downscaling
TVDI
SSEBOP
title Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in China
title_full Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in China
title_fullStr Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in China
title_full_unstemmed Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in China
title_short Improving the STARFM Fusion Method for Downscaling the SSEBOP Evapotranspiration Product from 1 km to 30 m in an Arid Area in China
title_sort improving the starfm fusion method for downscaling the ssebop evapotranspiration product from 1 km to 30 m in an arid area in china
topic evapotranspiration
data fusion
STARFM
downscaling
TVDI
SSEBOP
url https://www.mdpi.com/2072-4292/15/22/5411
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AT xiaogangwang improvingthestarfmfusionmethodfordownscalingthessebopevapotranspirationproductfrom1kmto30minanaridareainchina
AT lucabrocca improvingthestarfmfusionmethodfordownscalingthessebopevapotranspirationproductfrom1kmto30minanaridareainchina