Spatiotemporal variation and driving factors of normalized difference vegetation index(NDVI)in Yan'an City
[Objective]Vegetation is a principal component of terrestrial ecosystems.This study intends to investigate the spatiotemporal variation in regional vegetation coverage,and quantify the relative contributions of climate change and human activities,which can provide scientific support for future ecological environment construction and sustainable development of the region.[Method]Based on the MODIS-normalized difference vegetation index(NDVI)dataset and meteorological data of Yan'an City from 2001 to 2020,Mann-Kendall trend analysis,partial correlation analysis and residual analysis were employed to investigate the response of NDVI to climate change and human activities.[Result](1)From 2001 to 2020,the annual mean NDVI value in Yan'an City was 0.69,indicating a significant upward trend,with a spatial distribution pattern of high in the south and low in the north.(2)The impact of temperature and precipitation on NDVI varied significantly at different temporal scales.At the annual scale,NDVI was influenced more by precipitation than temperature.At the seasonal scale,NDVI in spring was influenced by both temperature and precipitation,while precipitation in summer had a greater impact on NDVI.In autumn and winter,the correlation between NDVI and temperature and precipitation was not significant in most regions.(3)The overall NDVI exhibited a trend of improvement,with 83.27％of the area showing significant improvement.(4)The impact of climate change and human activities on vegetation had a dual effect,with 91.26％of the area affected by both factors.The relative contributions of the two to vegetation change were 17.81％and 82.19％,respectively.[Conclusion]The overall vegetation in Yan'an City demonstrates a positive trend,and compared to climatic factors,human activities have a stronger driving effect on NDVI changes.[Ch,7 fig.3 tab.28 ref.]
normalized difference vegetation index(NDVI)driving factorsclimate changehuman activitiesYan'an City
万方数据
维普
