成渝经济区植被生态质量演变特征及驱动力分析

Evolution characteristics and driving forces of vegetation ecological quality in the Chengdu-Chongqing economic zone

利用MODIS NDVI数据反演成渝经济区2005年-2020年植被覆盖度(VFC)、植被净初级生产力(NPP),构建植被生态质量指数(Q)。通过趋势线性分析、相关性分析、残差分析,研究2005年-2020年成渝经济区植被生态质量时空变化特征,探索成渝经济区植被生态质量与气候和人类活动等影响因素的关系。结果表明:(1)2005年-2020年成渝经济区植被覆盖度达95%,NPP显著升高地区达93%,植被生态质量指数(Q)显著增加地区达92%,三者之间空间分布相对一致,植被生态质量整体提升;(2)通过趋势分析,降水、温度增加的空间分布和植被生态质量指数(Q)增加的空间分布范围相对一致,表明气候对改善植被生态质量有重要的驱动作用;相关性分析显示,植被生态质量指数(Q)与降水呈正相关,与温度呈负相关,且降水与植被生态质量指数(Q)的相关性强于温度;(3)驱动分区显示,成渝经济区植被生态质量变化约14.35%地区受气候因素驱动,约85.65%地区受非气候因素(自然灾害和人类活动等)的驱动;通过残差分析,2005年-2020年成渝经济区人类活动对植被的正面作用大于负面作用,说明成渝经济区植被生态质量的时空变化是气候因素和人类活动共同影响的结果。

MODIS NDVI data were used to invert vegetation fractional coverage( VFC) and net primary productivity( NPP) of the Chengdu-Chongqing Economic Zone from 2005 to 2020,and the vegetation ecological quality index( Q) was constructed.Through trend linear analysis,correlation analysis,and residual analysis,the temporal and spatial variation characteristics of vegetation ecological quality of the Chengdu-Chongqing Economic Zone from 2005 to 2020 were studied,and the relationship between vegetation ecological quality of Chengdu-Chongqing Economic Zone and influencing factors such as climate and human activities was explored.The results showed that:( 1) From 2005 to 2020,the vegetation fractional coverage of the Chengdu-Chongqing Economic Zone reached 95 %,the NPP significantly increased area reached 93 %,and the vegetation ecological quality index( Q) significantly increased area reached 92 %.The spatial distribution of the three was relatively consistent,and the vegetation ecological quality was improved as a whole.( 2) Through trend analysis,the spatial distribution of the increase of precipitation and temperature is relatively consistent with the increase of vegetation ecological quality index( Q),indicating that climate plays a vital role in driving the improvement of vegetation ecological quality;correlation analysis showed that vegetation ecological quality index( Q) was positively correlated with precipitation and negatively correlated with temperature,and the correlation between precipitation and vegetation ecological quality index( Q) was more substantial than that of temperature.( 3) The driving zoning shows that about 14.35 % of the changes in vegetation ecological quality in the Chengdu-Chongqing Economic Zone are driven by climate factors,and about 85.65 % are driven by non-climate factors( natural disasters and human activities,etc.);through residual analysis,the positive effect of human activities on vegetation in Chengdu-Chongqing Economic Zone from 2005 to 2020 is greater than the negative effect,indicating that the temporal and spatial variation of vegetation ecological quality in Chengdu-Chongqing Economic Zone is the result of the combined influence of climate factors and human activities.