Large-scale land cover mapping with the integration of multi-source information based on the Dempster–Shafer theory

Abstract

Land cover type is a crucial parameter that is required for various land surface models that simulate water and carbon cycles, ecosystem dynamics, and climate change. Many land use/land cover maps used in recent years have been derived from field investigations and remote-sensing observations. However, no land cover map that is derived from a single source (such as satellite observation) properly meets the needs of land surface simulation in China. This article presents a decision-fuse method to produce a higher-accuracy land cover map by combining multi-source local data based on the Dempster–Shafer (D–S) evidence theory. A practical evidence generation scheme was used to integrate multi-source land cover classification information. The basic probability values of the input data were obtained from literature reviews and expert knowledge. A Multi-source Integrated Chinese Land Cover (MICLCover) map was generated by combining multi-source land cover/land use classification maps including a 1:1,000,000 vegetation map, a 1:100,000 land use map for the year 2000, a 1:1,000,000 swamp-wetland map, a glacier map, and a Moderate-Resolution Imaging Spectroradiometer land cover map for China in 2001 (MODIS2001). The merit of this new map is that it uses a common classification system (the International Geosphere-Biosphere Programme (IGBP) land cover classification system), and it has a unified 1 km resolution. The accuracy of the new map was validated by a hybrid procedure. The validation results show great improvement in accuracy for the MICLCover map. The local-scale visual comparison validations for three regions show that the MICLCover map provides more spatial details on land cover at the local scale compared with other popular land cover products. The improvement in accuracy is true for all classes but particularly for cropland, urban, glacier, wetland, and water body classes. Validation by comparison with the China Forestry Scientific Data Center (CFSDC)–Forest Inventory Data (FID) data shows that overall forest accuracies in five provinces increased to between 42.19% and 88.65% for our MICLCover map, while those of the MODIS2001 map increased between 27.77% and 77.89%. The validation all over China shows that the overall accuracy of the MICLCover map is 71%, which is higher than the accuracies of other land cover maps. This map therefore can be used as an important input for land surface models of China. It has the potential to improve the modeling accuracy of land surface processes as well as to support other aspects of scientific land surface investigations in China.

Keywords:

• land cover
• data fusion
• remote sensing
• land surface modeling
• China

Acknowledgments

This work is supported by the Chinese Academy of Sciences Action Plan for West Development Project ‘Watershed Allied Telemetry Experimental Research (WATER)’ (KZCX2-XB2-09), the National Scientific Foundation of China (41001241, 40871190), the National High Technology R&D Program (863) project (grant number: 2009AA122104) and the Research Fund of State Key Laboratory of Resources and Environmental Information System. We thank the guidance of Prof. Jian Ni from the Institute of Botany, Chinese Academy of Sciences for assigning the correlation coefficient between the vegetation classes and IGBP classes, and Prof. Jianhua Wang from the Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences for assigning the correlation coefficient between the Chinese land use classes and IGBP classes. The China 1:100,000 land use data set was provided by Prof. Jiyuan Liu in the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences. We also thank Prof. Liu's enthusiastic help and encouragement. The forest distribution map is supported by the China forest source data center (http://www.cfsdc.org), Chinese Academy of Forestry. The 1:1,000,000 swamp-wetland map was provided by Prof. Shuqing Zhang in the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. Generous help for revising the article was also provided by Prof. Yuei-An Liou. We also thank the editor and the anonymous reviewers for their extremely helpful in revising the article.