吕梁山植被时空分布规律及地形差异影响

Temporal and spatial distribution of vegetation in Lyuliang mountain and the influence of topographical differences

基于2000—2018年MODIS NDVI数据,应用均值法、趋势分析法揭示吕梁山植被的时空变化特征,探究地形因子对植被变化的影响。结果表明,2000—2018年吕梁山年均归一化植被指数(NDVI)整体呈增加趋势。全区99.77%的植被覆盖稳定趋向良好转化,其中吕梁山脉中段NDVI较高,晋西、晋西北NDVI较低。地形差异在不同程度上对NDVI的空间分布产生影响,高程在1250~2400 m时,NDVI随海拔升高而增大,高程大于2400 m时,NDVI随海拔升高而减小;坡度以35°为界,坡度<35°时,NDVI均值随坡度增加而增大;阴坡的NDVI高于其他坡向且差异明显,平地的NDVI最小。

Based on the MODIS NDVI data from 2000 to 2018,the average method and trend analysis method were used to reveal the characteristics of temporal and spatial changes of vegetation in Lyuliang mountain,and to explore the impact of topographical factors on vegetation changes.The results showed that the average annual normalized difference vegetation index(NDVI)of Lyuliang mountain showed an overall increasing trend from 2000 to 2018.The vegetation coverage of 99.77%of the whole area was stable and tended to be well transformed.Among them,the NDVI value of the middle section of the Lyuliang mountain was highest,and the NDVI value of western and northwestern Shanxi was lowest.Terrain differences affect the spatial distribution of NDVI to varying degrees.The elevation of 1250~2400 m,the NDVI increased with the elevation,and the elevation more than 2400 m,the NDVI decreased with the elevation;The slope was bounded by 35°,When the slope was less than 35°,the mean value of NDVI increased with the increase of slope;The NDVI of shade slopes was higher than other slope directions and the difference was obvious,and the NDVI value of flat land was the smallest.