文献类型：期刊文献

英文题名：Spatial Representativeness of Gross Primary Productivity from Carbon Flux Sites in the Heihe River Basin, China

作者：Yu, Tao[1,2,3,4] Zhang, Qiang[3,4,5] Sun, Rui[3,4,5]

第一作者：Yu, Tao;余涛

通信作者：Sun, R[1];Sun, R[2];Sun, R[3]

机构：[1]Chinese Acad Forestry, Res Inst Forest Resource Informat Tech, Beijing 100091, Peoples R China;[2]Natl Forestry & Grassland Adm, Key Lab Forestry Remote Sensing & Informat Syst, Beijing 100091, Peoples R China;[3]Beijing Normal Univ, State Key Lab Remote Sensing Sci, Beijing 100875, Peoples R China;[4]Chinese Acad Sci, State Key Lab Remote Sensing Sci, Inst Remote Sensing & Digital Earth, Beijing 100875, Peoples R China;[5]Beijing Normal Univ, Fac Geog Sci, Beijing Engn Res Ctr Global Land Remote Sensing P, Inst Remote Sensing Sci & Engn, Beijing 100875, Peoples R China

年份：2021

卷号：13

期号：24

外文期刊名：REMOTE SENSING

收录：;EI(收录号：20215111370322);Scopus(收录号：2-s2.0-85121454870);WOS:【SCI-EXPANDED(收录号:WOS:000771728900009)】；

基金：This research was funded by the National Key R&D Program of China (2017YFA0603002), and the Fundamental Research Funds of CAF (CAFYBB2021SY009).

语种：英文

外文关键词：GPP; spatial representativeness; footprint; land cover types

摘要：Studying the spatial representativeness of carbon flux measurement data for typical land cover types can provide important information for benchmarking Earth system models and validating multiple-scale remote sensing products. In our study, daily gross primary productivity (GPP) was firstly derived from eddy covariance observation systems and seasonal variations in field GPP were analyzed at nine flux tower sites for typical land cover types in the Heihe River Basin, China. Then, the real-time footprint distance and climate footprint distance of the field GPP were obtained by using a footprint source area model. Lastly, multiple-scale GPP products were validated at footprint scale, and the impacts (measurement height, surface roughness and turbulent state of the atmosphere) on the footprint distance of field GPP were analyzed. The results of this paper demonstrated that climate footprint distances ranged from about 500 m to 1500 m for different land cover types in the Heihe River Basin. The accuracy was higher when validating MODIS GPP products at footprint scale (R-2 = 0.56, RMSE = 3.07 g C m(-2) d(-1)) than at field scale (R-2 = 0.51, RMSE = 3.34 g C m(-2) d(-1)), and the same situation occurred in the validation of high-resolution downscaled GPP (R-2 = 0.85, RMSE = 1.34 g C m(-2) d(-1) when validated at footprint scale; R-2 = 0.82, RMSE = 1.47 g C m(-2) d(-1) when validated at field scale). The results of this study provide information about the footprints of field GPP for typical land cover types in arid and semi-arid areas in Northwestern China, and reveal that precision may be higher when validating multiple-scale remote sensing GPP products at the footprint scale than at the field scale.