气候变化领域集成服务门户(CCPortal): Evaluation of the RF-Based Downscaled SMAP and SMOS Products Using Multi-Source Data over an Alpine Mountains Basin, Northwest China

CCPortal

DOI	10.3390/w13202875
	Evaluation of the RF-Based Downscaled SMAP and SMOS Products Using Multi-Source Data over an Alpine Mountains Basin, Northwest China
	Wen, Yuanyuan; Zhao, Jun; Zhu, Guofeng; Xu, Ri; Yang, Jianxia
通讯作者	Zhao, J (通讯作者)，Northwest Normal Univ, Coll Geog & Environm Sci, Lanzhou 730070, Peoples R China.
发表日期	2021
EISSN	2073-4441
卷号	13 期号:20
英文摘要	Passive microwave surface soil moisture (SSM) products tend to have very low resolution, which massively limits their application and validation in regional or local-scale areas. Many climate and hydrological studies are urgently needed to evaluate the suitability of satellite SSM products, especially in alpine mountain areas where soil moisture plays a key role in terrestrial atmospheric exchanges. Aiming to overcome this limitation, a downscaling method based on random forest (RF) was proposed to disaggregate satellite SSM products. We compared the ability of the downscaled soil moisture active passive (SMAP) SSM and soil moisture and ocean salinity satellite (SMOS) SSM products to capture soil moisture information in upstream of the Heihe River Basin by using in situ measurements, the triple collocation (TC) method and temperature vegetation dryness index (TVDI). The results showed that the RF downscaling method has strong applicability in the study area, and the downscaled results of the two products after residual correction have more details, which can better represent the spatial distribution of soil moisture. The validation with the in situ SSM measurements indicates that the correlation between downscaled SMAP and in situ SSM is better than downscaled SMOS at both point and watershed scales in the Babaohe River Basin. From the TC method, the root mean square error (RMSE) of the CLDAS (CMA land data assimilation system), downscaled SMAP and downscaled SMOS were 0.0265, 0.0255 and 0.0317, respectively, indicating that the downscaled SMAP has smaller errors in the study area than others. However, the soil moisture distribution in the study area shown by the SMOS downscaled results is closer than the downscaled SMAP to the degree of drought reflected by TVDI. Overall, this study suggests that the proposed RF-based downscaling method can capture the variation of SSM well, and the downscaled SMAP products perform significantly better than the downscaled SMOS products after the accuracy verification and error analysis of the downscaled results, and it should be helpful to facilitate applications for satellite SSM products at small scales.
关键词	SOIL-MOISTURE PRODUCT HIGH-RESOLUTION DISAGGREGATION PRECIPITATION ASSIMILATION TEMPERATURE MISSION ERRORS WATER
英文关键词	downscaling; random forest; SMAP; SMOS; surface soil moisture; triple collocation; validation
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Water Resources
WOS类目	Environmental Sciences ; Water Resources
WOS记录号	WOS:000714456800001
来源期刊	WATER
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/254023
作者单位	[Wen, Yuanyuan; Zhao, Jun; Zhu, Guofeng; Xu, Ri; Yang, Jianxia] Northwest Normal Univ, Coll Geog & Environm Sci, Lanzhou 730070, Peoples R China; [Zhu, Guofeng] Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, State Key Lab Cryosphere Sci, Lanzhou 730070, Peoples R China
推荐引用方式 GB/T 7714	Wen, Yuanyuan,Zhao, Jun,Zhu, Guofeng,et al. Evaluation of the RF-Based Downscaled SMAP and SMOS Products Using Multi-Source Data over an Alpine Mountains Basin, Northwest China[J]. 中国科学院西北生态环境资源研究院,2021,13(20).
APA	Wen, Yuanyuan,Zhao, Jun,Zhu, Guofeng,Xu, Ri,&Yang, Jianxia.(2021).Evaluation of the RF-Based Downscaled SMAP and SMOS Products Using Multi-Source Data over an Alpine Mountains Basin, Northwest China.WATER,13(20).
MLA	Wen, Yuanyuan,et al."Evaluation of the RF-Based Downscaled SMAP and SMOS Products Using Multi-Source Data over an Alpine Mountains Basin, Northwest China".WATER 13.20(2021).