唐白河流域植被覆盖时空变化研究

Research on Spatial and Temporal Changes in Vegetation Cover in the Tangbai River Basin

基于卫星遥感影像、气象站点数据和统计数据,综合采用Theil-Sen Median趋势分析法和Hurst指数法分析2000—2019年唐白河流域植被覆盖空间格局、年际变化特征和发展趋势,引入通径分析法揭示气象因子(年降水量和平均气温)对植被覆盖的影响机制,利用残差分析法量化气候变化和人类活动对植被变化的贡献率。结果表明:(1)唐白河流域植被覆盖呈西北部和东南部高、中部低的空间特征。(2)研究时段内,唐白河流域植被覆盖的变化以改善类型为主,其面积占流域总面积的96.27%,但流域NDVI增幅较小,且未来植被覆盖存在较大的退化风险。(3)气象因子对植被覆盖变化的直接影响大于间接影响,且主要表现为促进植被覆盖改善;年降水量是决定唐白河流域植被覆盖变化的关键气象因子,综合通径系数为0.224 9。(4)唐白河流域植被覆盖变化受气候变化和人类活动的共同影响,但人类活动的影响大于气候变化的影响。

Based on satellite remote sensing images,meteorological station data and statistical data,Theil-Sen Median trend analysis and Hurst index method were comprehensively used to analyze the spatial pattern,interannual change characteristics and development trend of vegetation cover in the Tangbai River Basin from 2000 to 2019.Path analysis was introduced to reveal the mechanism of meteorological factors(annual precipitation and average temperature)affecting vegetation cover.The contribution rate of climate change and human activities to vegetation change was quantified by residual analysis.The results are as follows.Firstly,the vegetation cover in the Tangbai River Basin is high in the northwest and southeast,and low in the middle.Secondly,during the study period,the vegetation cover of Tangbai River Basin was mainly changed by improving type,which accounted for 96.27%of the total area of the basin.However,the increase of NDVI is small,and there is a greater risk of degradation of vegetation cover in the future.Thirdly,the direct influence of meteorological factors on the change of vegetation cover is greater than the indirect influence,and are mainly seen as contributing to vegetation cover improvement.Annual precipitation is the key meteorological factor to determine vegetation cover change in Tangbai River Basin,and the comprehensive path coefficient is 0.2249.Finally,the vegetation cover change of Tangbai River Basin is affected by both climate change and human activities,but the influence of human activities is greater than that of climate change.