资源科学 ›› 2020, Vol. 42 ›› Issue (10): 2035-2046.doi: 10.18402/resci.2020.10.19

• 实证与应用 • 上一篇    

三种高分辨率地表蒸散发产品在华北地区的验证与对比

何韶阳1,2(), 田静1(), 张永强1   

  1. 1. 中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室,北京 100101
    2. 中国科学院大学,北京 100049
  • 收稿日期:2020-05-06 修回日期:2020-08-11 出版日期:2020-10-25 发布日期:2020-12-25
  • 通讯作者: 田静
  • 作者简介:何韶阳,女,河南新乡人,硕士生,研究方向为遥感水文和水足迹。E-mail: hesy.18s@igsnrr.ac.cn
  • 基金资助:
    国家自然科学基金项目(41671354);国家重点研发计划项目(2016YFA0602501)

Verification and comparison of three high-resolution surface evapotranspiration products in North China

HE Shaoyang1,2(), TIAN Jing1(), ZHANG Yongqiang1   

  1. 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2020-05-06 Revised:2020-08-11 Online:2020-10-25 Published:2020-12-25
  • Contact: TIAN Jing

摘要:

华北平原是中国重要的农业主产区,同时也是世界上水资源短缺最为严峻的地区之一。地表蒸散发(ET)是水资源消耗的最大项,因此获取准确的ET数据是华北平原水资源管理的重要基础。本文对全球3种高分辨率ET产品在华北地区进行精度验证和时空对比,以期为选择更适用于华北平原的高分辨率ET数据提供参考信息,更好地为水资源的研究和管理服务。通过与涡动相关测量数据对比,研究显示PML_V2产品在华北地区精度最高,其次是SSEBop_V4,最后是MOD16A2,相关系数分别为0.81、0.74和0.52;均方根误差分别为0.87、1.52和1.44 mm/d,PML_V2与站点观测值的波动趋势一致性最高。3种产品在小麦生长季的估算值与观测值的相关性均高于玉米生长季,SSEBop_V4和PML_V2估算值分别在小麦季和玉米季与观测值具有最高的相关性。通过3种产品相互之间的对比,结果发现PML_V2和SSEBop_V4在空间分布上较一致,相关系数最高,为0.76;MOD16A2的空间分布与其他2个产品差异较大;三者的最大差异出现在耕地区。从2003—2018年的变化趋势上,MOD16A2在3种土地利用类型下明显呈增加趋势,而SSEBop_V4和PML_V2无明显变化。该研究结果有助于评估每种产品的质量和不确定性,以改进ET算法和产品质量。

关键词: 蒸散发, 高分辨率, 精度验证, 时空变化, 涡动相关, Google Earth Engine (GEE), 生长季, 华北平原

Abstract:

The North China Plain is a critical agricultural region in China and one of the most severe water deficient areas in the world. Surface evapotranspiration (ET) is the largest component of water resource consumption, therefore obtaining accurate ET data is an important basis for water resource management on the North China Plain. In this study, accuracy verification and spatiotemporal comparison of three global high-resolution ET products were conducted in North China in order to provide a reference for the selection of a high-resolution ET data product that is more suitable for the North China Plain and can better serve the purpose of water resource research and management. Through the comparison with the eddy correlation measurement, the research showed that the PML_V2 product had the highest accuracy in North China, followed by SSEBop_V4 and MOD16A2, with correlation coefficients of 0.81, 0.74, and 0.52, respectively. The root mean square errors were 0.87, 1.52, and 1.44 (mm/d), respectively. PML_V2 showed the highest consistency with the fluctuation trend observed at the site. The correlation between the estimated and observed ET of the three products in the growing season of wheat was higher than that of maize. SSEBop_V4 ET and PML_V2 ET estimates had the highest correlation with the observed ET in wheat season and maize season, respectively. Comparatively, PML_V2 and SSEBop_V4 are more similar in spatial distribution, with the highest correlation coefficient of 0.76. The spatial distribution of MOD16A2 is very different from that of the other two products. The biggest difference of the three products appears in the cultivated land area. In 2003-2018, MOD16A2 showed a clear trend of increase for three land use types, while SSEBop_V4 and PML_V2 showed no obvious change.

Key words: evapotranspiration, high resolution, accuracy verification, spatiotemporal change, eddy covariance, Google Earth Engine (GEE), growing season, North China Plain