中国农业气象 ›› 2021, Vol. 42 ›› Issue (09): 788-804.doi: 10.3969/j.issn.1000-6362.2021.09.006

• 农业气象信息技术 栏目 • 上一篇    

风云卫星系列及CLDAS土壤水分产品多尺度精度验证与评价:以青藏高原那曲地区为例

王卓颖,刘杨晓月,杨骥,刘昭华   

  1. 1.江西理工大学土木与测绘工程学院,赣州 341000;2.广东省科学院广州地理研究所,广州 510170;3.南方海洋科学与工程广东省实验室(广州),广州 511458
  • 收稿日期:2021-01-18 出版日期:2021-09-20 发布日期:2021-09-11
  • 通讯作者: 刘杨晓月,助理研究员,研究方向为水文遥感,E-mail: lyxy@lreis.ac.cn;杨骥,正高级工程师,研究方向为地理空间智能与大数据,E-mail: yangji@gdas.ac.cn E-mail:lyxy@lreis.ac.cn
  • 作者简介:王卓颖,E-mail:1240833879@qq.com
  • 基金资助:
    国家自然科学基金委青年项目(42101475);博士后创新人才支持计划(BX20200100);南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0301);广东省科学院实施创新驱动发展能力建设专项(2019GDASYL−0301001;2019GDASYL−0501001;2019GDASYL−0502001);国家对地观测科学数据中心开放基金项目(No.NODAOP2020002)

Multi-scale Evaluation and Validation of Soil Moisture Products of FY-3B/3C and CLDAS: A Case Study in Naqu Region of the Qinghai-Tibet Plateau

WANG Zhuo-ying, LIU Yang-xiao-yue, YANG Ji, LIU Zhao-hua   

  1. 1. School of Civil and Surveying & Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China; 2. Guangzhou Institute of Geography, Guangdong Academy of Sciences, Guangzhou 510170; 3. Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou), Guangzhou 511458
  • Received:2021-01-18 Online:2021-09-20 Published:2021-09-11

摘要: 对风云卫星(FY-3B、FY-3C)系列土壤水分产品和中国气象局陆面数据同化系统CLDAS-V2.0(Chinese Land Data Assimilation System Version 2.0)土壤水分产品展开精度验证与评价,旨在明确中国土壤水分产品的时空序列精度特征,以期为后续土壤水分产品精度校正与反演模型改进提供参考。验证实验在青藏高原那曲地区开展,基于那曲地区大(1°×1°)、中(0.3°×0.3°)、小(0.1°×0.1°)三个尺度观测网中观测站点0-5cm、0-10cm和10-40cm土壤水分逐日观测资料进行评价,并加入全球陆面数据同化系统GLDAS-1(Global Land Data Assimilation System Vision 1.0)Noah土壤水分产品作为对比。结果表明:(1)时序性上,CLDAS-V2.0土壤水分产品表现出良好的时空连贯性,FY系列土壤水分产品空值普遍存在,在冰冻期尤为显著。FY及CLDAS-V2.0土壤水分产品多数时间存在高估现象,在降水事件发生后和植被生长期高估尤为明显。(2)各土壤水分产品在不同尺度观测网中的统计结果一致。但相较于大中尺度稀疏测站,各产品在小尺度密集观测网的评价结果更加稳定和优异。(3)0-5cm深度,CLDAS-V2.0土壤水分产品质量整体优于FY系列土壤水分产品,FY系列土壤水分日间观测产品精度高于夜间观测产品。10-40cm深度,CLDAS-V2.0土壤水分产品精度高于GLDAS-1 Noah土壤水分产品。结果表明中国自主研制的土壤水分产品数据集质量较为稳定、可靠。

关键词: 土壤水分, 风云卫星, 中国气象局陆面数据同化系统, 多尺度, 精度验证

Abstract: Soil moisture is an important variable for the surface hydrological cycle. High-precision soil moisture products, which have consistent time and space consistency, play a vital role in studying hydrological-driven climate and vegetation growth. In this paper, several soil moisture products were evaluated, including Fengyun satellite soil moisture products(FY-3B/3C) and Chinese Land Data Assimilation System Version 2.0(CLDAS-V2.0), aiming to clarify their accuracy characteristics of the time and space sequence. This study is expected to provide a reference for improving accuracy and inversion models of soil moisture products. The verification experiment was carried out in the Naqu region of the Qinghai-Tibet Plateau, based on the daily observed soil moisture data of 0-5cm, 0-10cm and 10-40cm at 1°×1°, 0.3°×0.3° and 0.1°×0.1° scale sparse observation networks. In comparison, the Global Land Data Assimilation System Vision 1.0(GLDAS-1) Noah soil moisture products were added to conduct the evaluate as a reference. The results showed that: (1) in terms of time sequence, CLDAS-V2.0 soil moisture products showed good temporal and spatial continuity. The null values of FY series soil moisture products were common existed, especially in freezing periods. FY and CLDAS-V2.0 soil moisture products usually overestimated the in-situ measurements, especially after the precipitation and in the vegetation growth period. (2) During the multi-scale evaluation, compared with the large-scale sparse observation station, the results were more stable and excellent on the small-scale sparse observation network. Correlation coefficients between soil moisture products and in-situ data at small scale sparse observation network were higher than those at large and middle scale sparse observation network, but Bias, RMSE and ubRMSD were lower. For example, correlation coefficient of CLDAS-V2.0 soil moisture product of 0-5cm at three(large, middle and small) scale sparse observation networks were 0.77, 0.78 and 0.79. (3) At multi-scale sparse observation networks, the results of validation were consistent. At 0−5cm, the quality of CLDAS-V2.0 soil moisture products was better than that of FY series soil moisture products on the whole. The daytime retrieved FY series soil moisture products were more accurate than the night observed data. At 0−10cm, GLDAS-1 Noah soil moisture products estimated closely soil moisture in Naqu region. However, R between GLDAS-1 Noah soil moisture products and in-situ data at multi-scale sparse observation networks were less than CLDAS-V2.0. At 10−40cm, CLDAS-V2.0 soil moisture products performed better than GLDAS-1 soil moisture products. The spatial statistical indices(Bias, RMSE and ubRMSD) of CLDAS-V2.0 and GLDAS-1 soil moisture products were closed, but correlation coefficients of CLDAS-V2.0 soil moisture products were much higher than those of GLDAS-1 soil moisture products. It showed that the quality of FY-3B/3C and CLDAS soil moisture products was relatively stable and reliable.

Key words: Soil moisture, Fengyun satellites, CLDAS, Multi-scale, Accuracy evaluation