Impacts Of Land Use And Land Cover Change On Vegetation Coverage In China North Korea And Russia

In the context of global warming,vegetation as a feedback to environmental changes,the growth state of vegetation is greatly affected by environmental changes.To study how vegetation responds to environmental changes,the primary task is to quantify changes in vegetation growth.In the study,we used the Normalized Difference Vegetation Index(NDVI)from 1982 to 2015 to systematically analyze the dynamic changes of vegetation in the transboundary regions of China,Democratic People's Republic of Korea(DPRK)and Russia in the past 34 years.The results of the study show that in the past 34 years,the average NDVI value of the cross-border region of China,DPRK and Russia is about 0.71,of which the NDVI value of Russia's Primorsky Krai is about 0.73,and the average value of NDVI in China is about 0.72.The average NDVI of the area is only 0.65.In the past 34 years,the NDVI value of the study area has shown an increasing trend.The interannual growth slope of NDVI is 0.3×10-3,of which the growth trend of Russia's Primorsky Krai is the most obvious(0.6 ×10-3),followed by DPRK(0.2 × 10-3),the slowest growth trend is on the Chinese side(0.1 ×10-3).In order to clarify the impact of vegetation cover change on NDVI in the study area,we used Landsat TM remote sensing data to construct land use status in the cross-border areas of China,DPRK and Russia in 1980,1990.2000 and 2015.We supervised and classified the remote sensing images of the cross-border areas of China,DPRK and Russia.The results of the conversion of various land use types showed that the total area of forest land increased from 1980 to 2015,an increase of 2.08%compared with 1980.The area of settlements increased the most,with an increase of 69.78%compared with 1980.The area of cultivated land decreased by 1.33 ×104 km2,which was 8.33%lower than that in 1980.The reduction of cultivated land was approximately equal to the increase of forest land and settlements.The maim performance is that from the different time periods,the 80s and 90s mainly showed an increase in forest land and a decrease in cultivated land;the magnitude of increase and decrease showed a decreasing trend with time.After 2000,the forest land showed a decrease in forest land,and both cultivated land and settlements increased.Finally,we conducted a comprehensive analysis of the variability of land use data and the interannual variability of NDVI data to identify ways in which human activities affect the dynamics of vegetation.The results show that there is a certain relationship between the changes of land use types and cultivated land types and ND VI trends,and the increase of settlements may be one of the ways to affect vegetation changes.Through literature surveys,it is found that these land-use changes that cause vegetation changes are mainly affected by human activities,especially the land policies promulgated by local governments.Through the quantification and correlation analysis of vegetation growth and land use data in the cross-border areas of China,DPRK and Russia,the study provides a certain data foundation for land management and ecological protection in the region,which is conducive to promoting rational land planning in cross-border areas.