1982—2015年内蒙古地区NDVI时空变化及驱动力分析

Temporal and Spatial Variations of NDVI and Its Driving Factors in Inner Mongolia from 1982 to 2015

以1982—2015年间内蒙古地区植被为研究对象,基于GIMMS NDVI3g、ERA5气象和土地覆盖数据,综合运用Theil-Sen median趋势分析、Mann-Kendall检验和Hurst指数、多元线性回归和残差分析方法,定量确定气候因子和人类活动对植被动态变化的影响程度。结果表明:1982—2015年,植被显著和极显著增加的面积分别占研究区总面积的8.83%、24.01%,显著和极显著减少的面积分别占比为4.20%、5.64%,变化不显著的面积占57.32%。研究区NDVI Hurst指数空间差异明显,植被整体呈现反持续性,但趋势不太明显。研究区年均降水与NDVI显著正相关的地区占研究区总面积的31.19%,显著负相关的占1.52%;年均温度与NDVI显著正相关的地区占研究区总面积的18.97%,显著负相关的占13.74%。1982—2015年人类活动、气候、气候和人类活动综合因素引起植被恢复的面积分别占总恢复面积的70.43%、7.82%、21.75%;人类活动、气候、气候和人类综合作用导致植被退化的面积分别占总退化面积的51.03%、26.28%、22.69%。1982—2015年内蒙古地区植被总体处于恢复状态,气候因子与植被显著相关的地区并不是植被变化的主要区域,引起植被恢复和退化的主要原因是人类活动。

Based on the data of GIMMS NDVI3g,ERA5 and land cover,the vegetation variations(1982-2015)were analyzed by using the Theil-Sen median trend analysis,Mann-Kendall test and Hurst index,multivariate linear regression and residual analysis were used to quantitatively determine the impact of climate factors and human activities on the dynamic change of vegetation.The findings indicated that from 1982 to 2015,the area with significant and extremely significant vegetation increase accounted for 8.83%and 24.01%of the total area of the study area;the area with significant and extremely significant vegetation decrease accounted for 4.20%and 5.64%,and the area without significant vegetation change accounted for 57.32%.The spatial difference of NDVI Hurst index was obvious in the study area.The vegetation overall presented reverse sustainability,but the trend was not obvious.The area with significant positive and negative correlation between annual precipitation and NDVI accounted for 31.19%and 1.52%of the study area;the area with significant positive and negative correlation between annual temperature and NDVI accounted for 18.97%and 13.74%.During 1982-2015,the vegetation restoration area caused by human activities,climate,climate and human activities integrated effects accounted for 70.43%,7.82%and 21.75%of the total vegetation restoration area,respectively;the vegetation degradation area resulted from human activities,climate,climate and human integrated effects accounted for 51.03%,26.28%and 22.69%,respectively.From 1982 to 2015,the vegetation in Inner Mongolia was generally in the recovery state.Areas where climatic factors were significantly related to vegetation were not the main areas of vegetation change,and human activities were the main causes of vegetation restoration and degradation.