Dynamic characteristics and attribution of vegetation in source region of Pearl River
With its special geographical location,the source regions of rivers play an important role in the protection and con-struction of national ecological environment.In this study,we used the Landsat TM,ETM and OLI_TIRS satellite images in non-monsoon season,combined with Sen's slope,Mann-Kendall trend test,partial correlation analysis and GIS space technology to study the characteristics of vegetation change and its influencing factors in the source region of the Pearl River since 1987.The re-sults showed that:① Since 1987,the annual average NDVI index of the non-monsoon season vegetation in the source region has been 0.19,and the inter-annual NDVI has fluctuated greatly,but there is no obvious long-term trend.The interdecadal NDVI of vegetation has roughly experienced a high-low-high-low dynamic process.② The difference of vegetation coverage in dif-ferent slopes is not obvious.The vegetation coverage is the highest in the range of[8°～15°),while the coverage is the lowest in the area of more than 35°,with NDVI of 0.22 and 0.16 respectively.③The spatial difference of vegetation coverage is large.The line of Dapo-Lingjiao-Reshui-Xize is a dividing line of vegetation coverage in the source area.The average NDVI of vegeta-tion in the west of this line is 0.32,while that in the east is only 0.15.④ The overall temperature shows a fluctuating upward trend,with a change rate of 0.51℃/10 a,while the precipitation shows a decreasing trend,with a rate of-4.70 mm/10 a.The impact of precipitation on vegetation NDVI is more obvious than that of temperature.⑤The construction of natural reserves,the"Pearl River Reserve"program and the project of returning farmland to forest and grassland have improved the regional ecological environment and effectively protected the vegetation.The research results can provide scientific basis for the protection and gov-ernance of the source area of the Pearl River.
vegetation dynamic changeclimate changehuman activityNDVIsource region of Pearl River
万方数据
维普
