Land Cover Mapping And Change In The Mongolian Plateau Based On Multi-source Data Fusion

Land cover is a variety of biological or physical cover types on the earth’s surface that can directly reflect the intensity and characteristics of human activities interacting with the natural environment.Accurate land cover datasets are not only key parameters in studies of water cycle,carbon cycle,and climate change simulation,but also important basic data to support ecosystem assessment and human-earth relationship studies.The Mongolian plateau is a typical climate change sensitive area in Asia with fragile ecosystems,and its land cover changes are closely related to major global issues such as material cycles and biodiversity.Therefore,the study of land cover mapping and change characteristics of Mongolian plateau based on the fusion of multi-source data is important to clarify the ecological and environmental changes of Mongolian plateau and promote the sustainable development of the region.In this paper,we analyzed the consistency and accuracy of Globe Land30,GLC＿FCS30 and FROM＿GLC global land cover datasets in Mongolian Plateau,and understood the applicability of different land cover datasets,then fused these three land cover data based on data consistency and fuzzy set theory to obtain the accurate land cover classification information of Mongolian Plateau in 2010 and 2020.The spatial and temporal characteristics of land cover changes on the Mongolian Plateau and the main influencing factors were revealed from the regional scale and the China-Mongolia-Russia scale.The main conclusions are as follows:(1)In terms of area consistency,the land composition descriptions of Globe Land30,GLC＿FCS30 and FROM＿GLC datasets are consistent,and the area correlation among the three land cover datasets is strong,with the correlation coefficient better than 0.881.In terms of spatial consistency,the spatial consistency of the three land cover datasets is low,the areas that were completely consistent among the three land cover datasets accounted for 55.34% of the total area of the Mongolian Plateau in 2010 and 61.87% in 2020.The reasons affecting the consistency are related to the different definitions of land classes in different datasets,the different classification methods used,and the confusion between the spectral characteristics of land classes such as forest,grassland and shrubland.(2)GLC＿FCS30 has the highest overall accuracy of about 78% in the Mongolian Plateau,followed by Globe Land30 with about 76%,and the lowest overall accuracy of FROM＿GLC,only 63.67% in 2010.The type accuracy of forest and water is good in all datasets;the type accuracy of grassland,bare land and built-up land is good only in Globe Land30 and GLC＿FCS30 in 2010 and good in all datasets in 2020;the type accuracy of cropland is good only in Globe Land30;the type accuracy of snow and ice is good only in GLC＿FCS30 data;the type accuracy of shrubland and wetland is poor(less than 60%)in all datasets.For the study of all elements of land cover on the Mongolian Plateau,the three land cover datasets are not ideal and cannot be used directly.When studying specific land types,the type accuracy of the three land cover datasets can be selected in a targeted manner.(3)The fused Mongolian plateau land cover dataset(MP＿LC)were improved in consistency and accuracy.In terms of consistency,the average overall consistency of the fusion dataset and the average consistency of each category improved by 3.54%-13.84% and 1.82%-27.92% in 2010 and 5.43%-8.91%and 0.59%-31.99% in 2020.In terms of accuracy,the overall accuracy of the fusion dataset in 2010 and2020 was 82.76% and 86.58%,which improved by 4.19%-19.09% and 8.25%-10.72% compared with the three sources of land cover datasets.Compared with the three sources land cover datasets,the producer accuracy and the user accuracy of each category in the fusion dataset were higher than those of any two sources of land cover datasets in different periods.(4)The land cover of the whole Mongolian Plateau in the last 10 years is characterized by the increase of grassland,rapid expansion of cropland and built-up land,and continuous decrease of forest and bare land.The integrated dynamic attitude of land cover change in the whole Mongolian Plateau is 2.83%,which is active.In the past 10 years,cropland and built-up land increased in Chinese part,Mongolian and Russian parts;forest decreased in the Russian part and increased in the Chinese and Mongolian parts;grassland increased in the Mongolian and Russian parts and decreased in the Chinese part;bare land continued to decrease in the Chinese and Mongolian parts and increased in the Russian part.Conversion between grassland and built-up land mainly occurred in the Chinese part,conversion between bare land and grassland mainly occurred in the Mongolian part,and conversion between grassland and forest mainly occurred in the Russian part.(5)Qualitative analysis shows that natural factors such as temperature and precipitation profoundly influence the macroscopic pattern of land cover change on the Mongolian plateau,and human factors such as population,economy and policies are the fundamental reasons for regional differences in land cover change between China,Mongolia and Russia.Quantitative analysis shows that land cover change in the Chinese part is mainly influenced by population and economic development,land cover change in the Mongolian part is mainly influenced by climate and economic development,and land cover change in the Russian part is mainly influenced by topography and climate.