Abstract
Abstract. Although wetlands are well known as one of the most important ecosystems in the world, there are still few global wetland mapping efforts at present. To evaluate the wetland-related types of data accurately for both the Global Land Cover 2000 (GLC2000) data set and MODIS land cover data set (MOD12Q1), we used the China wetland map of 2000, which was interpreted manually based on Landsat TM images, to examine the precision of these global land cover data sets from two aspects (class area accuracy, and spatial agreement) across China. The results show that the area consistency coefficients of wetland-related types between the two global data sets and the reference data are 77.27% and 56.85%, respectively. However, the overall accuracy of relevant wetland types from GLC2000 is only 19.81% based on results of confusion matrix of spatial consistency, and similarly, MOD12Q1 is merely 18.91%. Furthermore, the accuracy of the peatlands is much lower than that of the water bodies according to the results of per-pixel comparison. The categories where errors occurred frequently mainly include grasslands, croplands, bare lands and part of woodland (deciduous coniferous forest, deciduous broadleaf forest and open shrubland). The possible reasons for the low precision of wetland-related land cover types include (1)the different aims of various products and therefore the inconsistent wetland definitions in their systems; (2) the coarse spatial resolution of satellite images used in global data; (3) Discrepancies in dates when images were acquired between the global data set and the reference data. Overall, the unsatisfactory results highlight that more attention should be paid to the application of these two global data products, especially in wetland-relevant types across China.
Highlights
Wetlands are among the most valuable ecosystems in the world and supply highly valuable services for human welfare (Costanza, 1997)
Suggest that the precision wetland water based on computer automatic extraction methods could meet the demands of research at the global scale
Since the Global Land Cover 2000 (GLC2000) is developed by the coordination of the more than 30 groups, utilizing different classification algorithms, different evaluation methods and various regional schemes from region to region, the precision of GLC2000 is available at regional scale
Summary
Wetlands are among the most valuable ecosystems in the world and supply highly valuable services for human welfare (Costanza, 1997). There are four global land cover data sets available with 1 km spatial resolution, which include IGBP DISCover, UMD land cover products, the MODIS land cover products and Global Land Cover 2000(GLC2000), in which the AVHRR, MODIS, VEGETATION images are used respectively. Another new data set - Globcover Land Cover (2005 and 2009) with 300m spatial resolution - has been produced recently by ESA through an international partnership at global scale. All landcover types, including wetland, of the global land cover data sets were evaluated during existed research. The two global land cover data sets-GLC2000 and MOD12Q1 were evaluated based on China wetland mapping products in this study, and the results of evaluation are discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
