气候和地形对植被覆盖动态演化的影响研究

Impact of climate and topography on vegetation dynamics

基于MODIS NDVI遥感数据,结合气象和DEM等资料,采用线性回归分析、稳定性分析、R/S分析和相关性统计等数理方法,反演了2001—2010年贵州省植被覆盖时空演变趋势,研究不同因素对植被时空格局变化的驱动作用。研究表明:(1)2001—2010年贵州省植被覆盖呈增加趋势,增长率为6.25%,植被改善区域占比例为77.7%;(2)贵州省植被覆盖变异指数介于0.01—0.16之间,总体较稳定;从持续性来看,植被持续恢复是主旋律,反持续性主要集中在西部和东北地区。(3)贵州地区降雨量和温度空间分布格局较为明显,温度是影响该地区植被覆盖的主导因素,不同区域对气候因素的响应存在差异性。(4)各等级海拔植被覆盖均有上升,其中高海拔地区上升最为显著;中海拔地区是植被的主要分布区域,所占比例为72.2%且该海拔范围内NDVI均值差异不大。

Vegetation dynamics can represent the evolution of terrestrial ecosystems and have significant effects on the global climate change and hydrological cycle.This study quantified the temporal and spatial pattern of vegetation cover by using the MODIS NDVI,DEM,and meteorological data.This study was implemented in Guizhou from2001to2010.The main methods of this study include linear regression,coefficient of variation,R/S analysis,correlation statistics and other mathematical methods.Results showed that:(1)The vegetation coverage increased6.25%in Guizhou province from2001to2010.The proportion of vegetation recovery reached77.7%.(2)Vegetation coverage was stable in most areas of Guizhou province.This was proved by the variation coefficient between0.01-0.16.The sustained recovery of vegetation is dominant during this period while the anti-sustainability only located in the western and northeastern parts of Guizhou province.(3)The precipitation and temperature had obvious spatial gradient.The temperature was found to be the dominant factor in the study area.(4)The vegetation cover increased significantly,particularly at high-altitude regions.The regions of mediate altitude had the largest area of vegetation which contributions more than72.2%of the total area.Moreover,the NDVI values in this region had small variations compared with other regions.