四川省植被变化及其与气象因子的相关性分析

目的]分析四川省植被的变化特征及其与气象因子的相关性,为该区域的可持续发展提供理论依据。方法]采用一元线性回归方法,利用MODIS NDVI数据按不同植被类型对GIMMS NDVI数据进行模拟拓展,并采用变异系数、趋势分析和偏相关等方法进行变化分析和相关性分析。结果](1)近30a四川省植被NDVI以基本无变化和减小为主,减小的区域主要位于盆周山地、川东北的中海拔山地和川西北高原湿地,增长变化的区域较小,主要位于四川盆地中北部和川西高原西部;(2)植被受气温影响较大的区域主要分布在以灌丛和高山植被覆盖为主的甘孜西南部、西北部以及四川盆地的西南部,以针叶林和水稻种植为主的成都平原、四川盆地中部以及川东北的广元则对降水更敏感。结论]过去32a间四川省年最大NDVI变化具有明显的阶段性特征,整体上呈现下降趋势;植被NDVI的变化与降水和气温具有显著的线性相关关系,且气温和降水对植被变化的影响具有明显的区域差异。

Vegetation Change and Its Correlation with Meteorological Factors in Sichuan Province

Objective] This paper analyzed the characteristics of vegetation change and its correlation with meteorological factors in Sichuan Province in order to provide a theoretical basis for sustainable development of the region. Methods] MODIS NDVI data was adopted to extend GIMMS NDVI vegetation types-based data using linear regression method. Then, the characteristics of vegetation change and its correlation with meteorological factors were studied by using coefficient of variation, trend analysis and partial correlation analysis. Results] (1) According to NDVI, most areal vegetation of Sichuan Province were substantially unchanged and decreased. Decreased regions were mainly located in the medium altitude mountain of the northeast areas, the mountain areas around Sichuan Basin and the plateau wetlands. The increased area was small, mainly located in the north central of Sichuan Basin and the west of Western Sichuan plateau. (2) The influence of temperature and precipitation changes on vegetation was different. In the southwestern and the northwestern of Ganzi area, as well as the southwestern of Sichuan Basin, where were mainly covered with shrubs and alpine vegetation, these vegetations was more influenced by the temperature. In the northeast of Sichuan Province and the central of Sichuan Basin, where the vegetation were dominated by coniferous forest and rice cultivation, were more sensitive to precipitation. Conclusion] The change of annual maximum NDVI displayed obvious successive characteristics over the past 32 years, an overall downward trend was observed. The correlations of NDVI with precipitation and temperature displayed significant linear correlation, and the effects of temperature and precipitation on vegetation change had obvious regional differences.