长株潭核心区植被覆盖度动态监测与分析

Monitoring and Analysis of Vegetation Fractional Cover in Changsha-Zhuzhou-Xiangtan Core Region Based on Remote Sensing Data

以2000年Landsat5、2013年Landsat8两个时相遥感影像,利用像元二分法模型反演获得2个时期的植被覆盖度,并通过研究区域内2期植被覆盖度的时空变化特征、近13年的区域植被覆盖度转移矩阵、植被改善/退化状况及驱动力,定量分析了长株潭核心区13年植被覆盖度的时序变化和空间分布特征。研究结果表明:长株潭核心区近13年植被覆盖度保持总体稳定并有所改善,平均覆盖度由2000年的0.573 9上升到2013年的0.601 5,植被退化区主要集中在长沙、株洲、湘潭3市城区及周边区域,另外长株潭绿心区植被覆盖度也有小幅下降;长株潭核心区植被覆盖与气候变化有一定关联,但人口增长、土地利用类型变化、城市化进程以及政策等人为因素是影响植被覆盖变化的主要因素。

Based on current status and temporal Xiangtan （CZT） core region, the factors leading fractional cover were discussed. The Landsat 5/8 al cover in CZT core region. And through image dynamics of the vegetation fractional cover in Changsha-Zhuzhou- to the change and the direction of the evolution of the vegetation data in 2000 and 2013 were used to derive the vegetation fraction- analyzing and processing, the NDVI values of pure vegetation and pure soil in such two periods were obtained. Then the vegetation fractional cover distribution maps in 2000 and 2013 were got by conducting the pixel dichotomy model. At last, the temporal and spatial changes of vegetation fractional cover, such as transfer matrixes, the vegetation improvement/degradation and the driving forces which lead to such changes were analyzed. The conclusions of quantitative analysis showed that the mean vegetation fractional cover of CZT core region has been improved from O. 573 9 in 2000 to 0. 601 5 in 2013. Most of vegetation degradation oc- curred in Changsha, Zhuzhou, Xiangtan and the surrounding area. In particular, the vegetation fractional cover in Green-core of CZT declined a little bit. The driving forces analysis showed that the changes of vegetation fractional cover in CZT core region were correlated with the climate change, while the population growth, land-use change, urbanization and policy were the key factors influencing the vegetation fractional cover.