Identifying and Quantifying Pixel-Level Uncertainty among Major Satellite Derived Global Land Cover Products
- PDF / 20,982,289 Bytes
- 16 Pages / 611.98 x 792 pts (letter) Page_size
- 5 Downloads / 191 Views
Advanced Applications of Meteorological Satellite Observations in Ecological Remote Sensing
AUGUST 2020
Identifying and Quantifying Pixel-Level Uncertainty among Major Satellite Derived Global Land Cover Products Hao GAO1*, Gensuo JIA2, and Yu FU3 1 National Satellite Meteorological Center, China Meteorological Administration, Beijing 100081 2 Key Laboratory of Regional Climate–Environment for Temperate East Asia (RCE-TEA), Chinese Academy of Sciences, Beijing 100029 3 Climate Change Research Center, Chinese Academy of Sciences, Beijing 100029 (Received November 21, 2019; in final form June 4, 2020)
ABSTRACT Accurate global land cover (GLC), as a key input for scientific communities, is important for a wide variety of applications. In order to understand the current suitability and limitation of GLC products, the discrepancy and pixellevel uncertainty in major GLC products in three epochs are assessed in this study by using an integrated uncertainty index (IUI) that combines the thematic uncertainty and local classification accuracy uncertainty. The results show that the overall spatial agreements (Ao values) between GLC products are lower than 58%, and the total areas of forests are very consistent in major GLC products, but significant differences are found in different forest classes. The misclassification among different forest classes and mosaic types can account for about 20% of the total disagreements. The mean IUI almost reaches 0.5, and high uncertainty mostly occurs in transition zones and heterogeneous areas across the world. Further efforts are needed to make in the land cover classifications in areas with high uncertainty. Designing a classification scheme for climate models, with explicit definitions of land cover classes in the threshold of common attributes, is urgently needed. Information of the pixel-level uncertainty in major GLC products not only give important implications for the specific application, but also provide a quite important basis for land cover fusion. Key words: global land cover (GLC), discrepancies, thematic similarity, local accuracy, pixel-level uncertainty Citation: Gao, H., G. S. Jia, and Y. Fu, 2020: Identifying and quantifying pixel-level uncertainty among major satellite derived global land cover products. J. Meteor. Res., 34(4), 806–821, doi: 10.1007/s13351-020-9183-x.
1.
Introduction
Land cover plays an important role in the biogeochemistry of earth system, which influences the carbon, moisture, energy, and momentum exchanges between the land and atmosphere (Findell et al., 2007; Sterling et al., 2013). As an essential variable considered by the Global Climate Observing System (GCOS), land cover is used in science and policy applications, such as the climate change, food security, biodiversity conservation, ecosystem assessment, and hydrological and dynamic vegetation modeling. A number of global land cover (GLC) products have been produced based on the remote sensing data in response to the need for land cover information and dy-
namics in the past decades (Hans
