# Uncertainty Analysis of Multisource Land Cover Products in China
## 5 Conclusions  
This study used three multisource land cover products from 2001 to 2012 in China to explore their area, spatiotemporal changes, and resolution uncertainty, revealing the essential differences between qualitative, semiquantitative, and quantitative products. The uncertainty of land cover products in different regions and the uncertainty of resolution have been explored, laying the foundation for the uncertainty evaluation of remote sensing inversion, model simulation, and subpixel estimation. The results showed that the overall consistency of the three land cover products was relatively strong, the area uncertainty was relatively small, and they were relatively consistent in China. Considering forest coverage, VCF and ESA CCI products had the slightest uncertainty, and considering nontree vegetation, ESA CCI and MODIS products had the slightest uncertainty. However, the spatial distributions of the three products were locally inconsistent, and different regions may show opposite conclusions regarding spatiotemporal changes. The regions with significant spatial differences were plateaus or hills. The products with the best overall consistency were VCF and ESA CCI, and the worst were VCF and MODIS. The semiquantitative ESA CCI product had both qualitative and quantitative characteristics and was a better choice. As the resolution increased, the consistency of each product was enhanced, but the accuracy was inevitably reduced. The contradiction between accuracy and resolution was balanced through an inflection point of resolution. When scholars conduct remote sensing inversion, model simulation, and subpixel program research, the uncertainty system of multisource land cover products can assess the reliability of different studies. Therefore, in future research, we will establish a global-scale, multiproduct consistency evaluation system.  
Conceptualization, J.J.; Data curation, L.W.; Formal analysis, L.W.; Methodology, J.J.; Resources, J.J.; Visualization, L.W. All authors have read and agreed to the published version of the manuscript.  
This work was funded by the Fundamental Research Funds for the Central Universities (grant number B200202016).  
Not applicable.  
The study did not report any data.  
We would like to acknowledge [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] from Hohai University for the constructive suggestions. Data of the MCD12 product used are available at [[https://modis.gsfc.nasa.gov/data](https://modis.gsfc.nasa.gov/data)]([https://modis.gsfc.nasa.gov/data](https://modis.gsfc.nasa.gov/data)) (accessed on 22 October 2014), data of the ESA CCI product are available at [[http://maps.elei.ucl.ac.be/CCI/viewer/download](http://maps.elei.ucl.ac.be/CCI/viewer/download)]([http://maps.elei.ucl.ac.be/CCI/viewer/download](http://maps.elei.ucl.ac.be/CCI/viewer/download)) (accessed on 22 December 2019), and data of MEASURES VCF are available at [[https://lpdaac.usgs.gov/productsearch/](https://lpdaac.usgs.gov/productsearch/)]([https://lpdaac.usgs.gov/productsearch/](https://lpdaac.usgs.gov/productsearch/)) (accessed on 19 February 2020).  
The authors declare no conflict of interest.