2007—2016年广西植被覆盖时空分布特征及其驱动因素

Changes of Vegetation NDVI and Its Driving Factors from 2007 to 2016 in Guangxi,China

为探索广西植被变化的规律及主导因素,本文利用植被归一化(NDVI)数据、气象数据和DEM数据,通过一元线性回归方法、变异系数以及相关分析法,对比分析不同植被类型、土壤类型、海拔高度的植被NDVI值的变化。研究表明:(1)广西植被覆盖状况良好,总体呈上升趋势。草丛、阔叶林、针叶林的植被覆盖高。(2)广西58.76%区域的植被处于非常稳定状态,37.84%区域的植被处于稳定状态,1.07%区域的植被变异剧烈,即大部分地区植被呈稳定状态,极少数地区变异剧烈。阔叶林处于稳定状态,变化较小。(3)年平均NDVI值与年降水、气温总体呈负相关。(4)针叶林、阔叶林、灌丛和草丛的植被覆盖呈轻度增加。赤红壤、红壤、黄壤、石灰土、粗骨土地区的植被覆盖呈增加趋势,而砖红壤地区的呈下降趋势。(5)NDVI值随着海拔高度的变化比较明显,总体变化呈"增加—下降—增加"的趋势。

To explore general regularity of vegetation cover change in Guangxi and the leading influencing factors, the vegetation change trend from 2007 to 2016 was analyzed based on the vegetation normalized index data, meteorological data and digital elevation model （DEM） data using a linear regression method and coefficient of variation and correlation analysis. The results revealed that： （1） the vegetation coverage in Guangxi was in good condition with a growing tendency, and the perspective of vegetation,grassland, broadleaf forests, coniferous forests of NDVI is high. （2） most of the vegetation covers an Guangxi are stable as revealed by the data of 58.76% in an extremely stable state and 37.84% in a stable state with only 1.07% in a state underwent dramatic variation. Broadleaf forests are in a stable state with only a small change. （3）The annual average NDVI presented a negative correlation with the annual precipitation and the annual temperature. （4） Broadleaf forests, Coniferous forests, Grassland, Shrub showed a slightly increasing trend. And the vegetation cover area on Latosolic red earth, Red earth, Yellow earths, Limestone soils, Skeletal soil showed an increasing trend, but the Latosol vegetation cover area showed a declining trend. （5）NDVI change apparently with the change of altitude with an overall trend of increasing-declining-increasing.