黄河流域上游植被覆盖变化特征及其影响因素

Characteristics of vegetation cover changes in the upper reaches of the Yellow River Basin and the influencing factors

植被覆盖度能很好的反映流域生态状况,遥感技术为大规模、高效、精准地监测植被覆盖变化提供了重要手段。本文分析了2001—2020年黄河流域上游植被覆盖度时空变化特征,利用Hurst指数与Cv系数检验其持续性、稳定性,分析气候、地形和人口对植被覆盖度变化的影响。结果表明:(1)植被覆盖度由东北向西南递增,69.25%区域呈增长趋势。稳定区域面积占总面积的73.79%,强持续性区域面积占比为66.49%。(2)植被覆盖度与降水正相关区域占比75.63%,与气温正相关区域占比39.28%。(3)植被覆盖度随着高程的增加先升高后下降,与坡度呈正相关,与坡向关系不显著。(4)植被覆盖度在人口密度为65~85人·km^(-2)与GDP为27000~37000元·km^(-2)时最高,人类活动对黄河流域上游植被覆盖变化呈现促进作用。研究结果为黄河流域上游生态高质量发展提供科学参考。

Vegetation coverage provides a good reflection of the ecological status of the watershed,and remote sensing technology is important for the large-scale,efficient,and accurate monitoring of changes in vegetation coverage.This study examined the temporal and spatial variation characteristics of vegetation coverage in the up-per reaches of the Yellow River Basin from 2001 to 2020,using the Hurst index and Cv coefficient to test persis-tence and stability.The effects of climate,topography,and population on changes in vegetation coverage were an-alyzed.The results showed that the vegetation coverage increased from northeast to southwest,with an increasing trend in 69.25%of the areas.Stable areas accounted for 73.79%of the total area,and areas of strong sustainabili-ty accounted for 66.49%.(2)Of the total area,75.63%was positively correlated with precipitation and 39.28%was positively correlated with temperature.(3)As elevation increased,vegetation coverage first increased and then decreased;coverage was positively correlated with slope but not significantly related to aspect.(4)The vege-tation coverage was highest when the population density was 65-85 individuals·km^(-2) and the GDP was 27000-37000 yuan·km^(-2),indicating that human activities promoted changes in the vegetation cover in the upper reaches of the Yellow River Basin.The results of this study provide a scientific reference to support the high-quality eco-logical development of the upper reaches of the Yellow River Basin.